diff --git a/dataset_toolkits/datasets/HSSD.py b/dataset_toolkits/datasets/HSSD.py
new file mode 100644
index 0000000..465e6a1
--- /dev/null
+++ b/dataset_toolkits/datasets/HSSD.py
@@ -0,0 +1,103 @@
+import os
+import re
+import argparse
+import tarfile
+from concurrent.futures import ThreadPoolExecutor
+from tqdm import tqdm
+import pandas as pd
+import huggingface_hub
+from utils import get_file_hash
+
+
+def add_args(parser: argparse.ArgumentParser):
+    pass
+
+
+def get_metadata(**kwargs):
+    metadata = pd.read_csv("hf://datasets/JeffreyXiang/TRELLIS-500K/HSSD.csv")
+    return metadata
+        
+
+def download(metadata, output_dir, **kwargs):    
+    os.makedirs(os.path.join(output_dir, 'raw'), exist_ok=True)
+
+    # check login
+    try:
+        huggingface_hub.whoami()
+    except:
+        print("\033[93m")
+        print("Haven't logged in to the Hugging Face Hub.")
+        print("Visit https://huggingface.co/settings/tokens to get a token.")
+        print("\033[0m")
+        huggingface_hub.login()
+        
+    try:
+        huggingface_hub.hf_hub_download(repo_id="hssd/hssd-models", filename="README.md", repo_type="dataset")
+    except:
+        print("\033[93m")
+        print("Error downloading HSSD dataset.")
+        print("Check if you have access to the HSSD dataset.")
+        print("Visit https://huggingface.co/datasets/hssd/hssd-models for more information")
+        print("\033[0m")
+    
+    downloaded = {}
+    metadata = metadata.set_index("file_identifier")
+    with ThreadPoolExecutor(max_workers=os.cpu_count()) as executor, \
+        tqdm(total=len(metadata), desc="Downloading") as pbar:
+        def worker(instance: str) -> str:
+            try:
+                huggingface_hub.hf_hub_download(repo_id="hssd/hssd-models", filename=instance, repo_type="dataset", local_dir=os.path.join(output_dir, 'raw'))
+                sha256 = get_file_hash(os.path.join(output_dir, 'raw', instance))
+                pbar.update()
+                return sha256
+            except Exception as e:
+                pbar.update()
+                print(f"Error extracting for {instance}: {e}")
+                return None
+            
+        sha256s = executor.map(worker, metadata.index)
+        executor.shutdown(wait=True)
+
+    for k, sha256 in zip(metadata.index, sha256s):
+        if sha256 is not None:
+            if sha256 == metadata.loc[k, "sha256"]:
+                downloaded[sha256] = os.path.join('raw', k)
+            else:
+                print(f"Error downloading {k}: sha256s do not match")
+
+    return pd.DataFrame(downloaded.items(), columns=['sha256', 'local_path'])
+
+
+def foreach_instance(metadata, output_dir, func, max_workers=None, desc='Processing objects') -> pd.DataFrame:
+    import os
+    from concurrent.futures import ThreadPoolExecutor
+    from tqdm import tqdm
+    
+    # load metadata
+    metadata = metadata.to_dict('records')
+
+    # processing objects
+    records = []
+    max_workers = max_workers or os.cpu_count()
+    try:
+        with ThreadPoolExecutor(max_workers=max_workers) as executor, \
+            tqdm(total=len(metadata), desc=desc) as pbar:
+            def worker(metadatum):
+                try:
+                    local_path = metadatum['local_path']
+                    sha256 = metadatum['sha256']
+                    file = os.path.join(output_dir, local_path)
+                    record = func(file, sha256)
+                    if record is not None:
+                        records.append(record)
+                    pbar.update()
+                except Exception as e:
+                    print(f"Error processing object {sha256}: {e}")
+                    pbar.update()
+            
+            executor.map(worker, metadata)
+            executor.shutdown(wait=True)
+    except:
+        print("Error happened during processing.")
+        
+    return pd.DataFrame.from_records(records)
diff --git a/glb2svg.py b/glb2svg.py
new file mode 100644
index 0000000..e3f7e7e
--- /dev/null
+++ b/glb2svg.py
@@ -0,0 +1,555 @@
+import math
+import secrets
+from collections import defaultdict
+from datetime import datetime
+
+import os
+import subprocess
+from pathlib import Path
+import logging
+from typing import Optional
+
+import imageio
+import numpy as np
+import torch
+from PIL import Image
+
+# ---------- PyTorch3D ----------
+from pytorch3d.structures import Meshes
+from pytorch3d.renderer import (
+    RasterizationSettings, MeshRasterizer,
+    MeshRenderer, BlendParams, SoftSilhouetteShader,
+    look_at_view_transform, OrthographicCameras
+)
+from pytorch3d.renderer.mesh.rasterizer import Fragments
+
+# ---------- SVG / Image ----------
+import svgwrite
+from skimage import measure
+
+# ---------- pythonocc (OCC) ----------
+from OCC.Core.STEPControl import STEPControl_Reader
+from OCC.Core.TopAbs import TopAbs_FACE
+from OCC.Core.TopExp import TopExp_Explorer
+from OCC.Core.BRep import BRep_Tool
+from OCC.Core.BRepMesh import BRepMesh_IncrementalMesh
+from OCC.Core.TopLoc import TopLoc_Location
+from OCC.Core.ShapeFix import ShapeFix_Shape
+
+# ---------- Combine SVG ----------
+import svgutils.transform as st
+from svgutils.compose import Unit
+import cairosvg
+
+from trellis.pipelines import TrellisImageTo3DPipeline
+from trellis.utils import render_utils, postprocessing_utils
+
+logger = logging.getLogger(__name__)
+
+"""single image to 3D"""
+
+
+def generate_unique_name(original_name: str) -> str:
+    stem, ext = os.path.splitext(original_name)
+    timestamp = datetime.now().strftime("%Y%m%d_%H%M%S")
+    random_part = secrets.token_hex(4)  # 8位随机十六进制
+    return f"{stem}_{timestamp}_{random_part}{ext}"
+
+
+def image_to_3d(image: list[str], out_dir: str = "trellis_out", single_image: bool = False, seed: int = 1,
+                steps_sparse: int = 12, cfg_sparse: float = 7.5, steps_slat: int = 12,
+                cfg_slat: float = 3.0, simplify: float = 0.95, texture_size: int = 1024,
+                save_video: bool = False, fps: int = 30, video_gs_name: str = "sample_gs.mp4", video_rf_name: str = "sample_rf.mp4", video_mesh_name: str = "sample_mesh.mp4"):
+    os.makedirs(out_dir, exist_ok=True)
+    # Optional env
+    os.environ.setdefault("SPCONV_ALGO", "native")
+    pipeline = TrellisImageTo3DPipeline.from_pretrained("microsoft/TRELLIS-image-large")
+    pipeline.cuda()
+
+    if single_image:
+        image = Image.open(image[0])
+        outputs = pipeline.run(
+            image,
+            seed=seed,
+            sparse_structure_sampler_params={
+                "steps": steps_sparse,
+                "cfg_strength": cfg_sparse,
+            },
+            slat_sampler_params={
+                "steps": steps_slat,
+                "cfg_strength": cfg_slat,
+            },
+        )
+    else:
+        images = [Image.open(p) for p in image]
+        outputs = pipeline.run_multi_image(
+            images,
+            seed=seed,
+            sparse_structure_sampler_params={
+                "steps": steps_sparse,
+                "cfg_strength": cfg_sparse,
+            },
+            slat_sampler_params={
+                "steps": steps_slat,
+                "cfg_strength": cfg_slat,
+            },
+        )
+
+    if save_video:
+        video = render_utils.render_video(outputs["gaussian"][0])["color"]
+        imageio.mimsave(os.path.join(out_dir, video_gs_name), video, fps=fps)
+
+        video = render_utils.render_video(outputs["radiance_field"][0])["color"]
+        imageio.mimsave(os.path.join(out_dir, video_rf_name), video, fps=fps)
+
+        video = render_utils.render_video(outputs["mesh"][0])["normal"]
+        imageio.mimsave(os.path.join(out_dir, video_mesh_name), video, fps=fps)
+
+    glb_path = os.path.join(out_dir, generate_unique_name("sample.glb"))
+    ply_path = os.path.join(out_dir, generate_unique_name("sample.ply"))
+
+    glb = postprocessing_utils.to_glb(
+        outputs["gaussian"][0],
+        outputs["mesh"][0],
+        simplify=simplify,
+        texture_size=texture_size,
+    )
+
+    # 先写到临时路径
+    glb.export(glb_path)
+    outputs["gaussian"][0].save_ply(ply_path)
+
+    return glb_path, ply_path
+
+
+"""
+glb_to_obj
+"""
+
+
+def glb_to_obj(glb_input, obj_output_dir="obj_output"):
+    obj_path = os.path.join(obj_output_dir, generate_unique_name("sample.obj"))
+    os.makedirs(obj_output_dir, exist_ok=True)
+
+    cmd = [
+        "blender",
+        "-b",
+        "-P",
+        "0_glb_to_obj.py",
+        "--",
+        "--input",
+        glb_input,
+        "--output",
+        obj_path
+    ]
+
+    result = subprocess.run(cmd, capture_output=True, text=True)
+    print(result)
+    print("\n")
+    if result.returncode != 0:
+        raise RuntimeError(
+            f"Blender failed\nstdout:\n{result.stdout}\nstderr:\n{result.stderr}"
+        )
+
+    return obj_path
+
+
+"""
+obj_to_step
+"""
+
+
+def obj_to_step(
+        input_obj: str | Path,
+        output_dir: str | Path,
+        script_path: str | Path = "1_obj_to_step.py",
+        timeout: int = 120,  # 秒，建议根据实际转换耗时调整
+        freecadcmd_path: Optional[str] = None
+) -> bool:
+    """
+    把 OBJ 转 STEP 的 FreeCAD 命令封装成函数
+    返回 True 表示成功，False 表示失败
+    """
+    input_obj = Path(input_obj).resolve()
+    output_dir = Path(output_dir).resolve()
+    script_path = Path(script_path).resolve()
+
+    print(f"input_obj : {input_obj}")
+    print(f"output_dir : {output_dir}")
+    print(f"script_path : {script_path}")
+
+    if not input_obj.exists():
+        raise FileNotFoundError(f"输入文件不存在: {input_obj}")
+    if not script_path.exists():
+        raise FileNotFoundError(f"转换脚本不存在: {script_path}")
+
+    # 构造 -c 参数（完全复刻你原来的命令）
+    python_code = f'''import sys
+sys.argv = ["{script_path.name}", "{input_obj}", "{output_dir}"]
+exec(open("{script_path}", "r", encoding="utf-8").read())'''
+
+    cmd = [
+        freecadcmd_path or "freecadcmd",  # 如果不在 PATH 中，可传入绝对路径
+        "-c",
+        python_code
+    ]
+
+    try:
+        result = subprocess.run(
+            cmd,
+            capture_output=True,
+            text=True,
+            check=True,  # 自动抛出 CalledProcessError
+            timeout=timeout,
+            cwd=script_path.parent  # 让脚本能找到相对路径文件
+        )
+
+        logger.info(f"FreeCAD 转换成功: {input_obj.name} → {output_dir}")
+        print(f"FreeCAD 转换成功: {input_obj.name} → {output_dir}")
+        if result.stdout:
+            logger.debug(result.stdout)
+        return result.stdout.split()[-1]
+
+    except subprocess.TimeoutExpired:
+        logger.error(f"FreeCAD 转换超时（>{timeout}s）: {input_obj}")
+        return False
+    except subprocess.CalledProcessError as e:
+        logger.error(f"FreeCAD 执行失败: {e.stderr}")
+        return False
+    except Exception as e:
+        logger.exception("未知错误")
+        return False
+
+
+"""
+step to svg
+"""
+
+
+def autodevice():
+    return torch.device("cuda:0" if torch.cuda.is_available() else "cpu")
+
+
+def read_step_solid(path: str):
+    reader = STEPControl_Reader()
+    stat = reader.ReadFile(path)
+    if stat != 1:
+        raise RuntimeError(f"STEP 读取失败: {path}")
+    reader.TransferRoots()
+    shape = reader.OneShape()
+    fixer = ShapeFix_Shape(shape)
+    fixer.Perform()
+    return fixer.Shape()
+
+
+def triangulate(shape, deflection=0.5, angle=0.5):
+    """OCC 三角化：返回 (V(np.float32 N×3), F(np.int64 M×3))"""
+    BRepMesh_IncrementalMesh(shape, deflection, False, angle, True)
+    verts, faces, v_off = [], [], 0
+    exp = TopExp_Explorer(shape, TopAbs_FACE)
+    while exp.More():
+        face = exp.Current()
+        loc = TopLoc_Location()
+        tri = BRep_Tool.Triangulation(face, loc)
+        if tri is not None:
+            nb_nodes = tri.NbNodes()
+            has_nodes_arr = hasattr(tri, "Nodes")
+            for i in range(1, nb_nodes + 1):
+                p = tri.Nodes().Value(i) if has_nodes_arr else tri.Node(i)
+                p = p.Transformed(loc.Transformation())
+                verts.append([p.X(), p.Y(), p.Z()])
+            nb_tris = tri.NbTriangles()
+            has_tris_arr = hasattr(tri, "Triangles")
+            for i in range(1, nb_tris + 1):
+                t = tri.Triangles().Value(i) if has_tris_arr else tri.Triangle(i)
+                a, b, c = t.Get()
+                faces.append([v_off + a - 1, v_off + b - 1, v_off + c - 1])
+            v_off += nb_nodes
+        exp.Next()
+    if not verts or not faces:
+        raise RuntimeError("三角化为空，尝试减小 --defl")
+    return np.asarray(verts, np.float32), np.asarray(faces, np.int64)
+
+
+def normalize_mesh_np(verts: np.ndarray, unit_scale=1.0):
+    c = verts.mean(axis=0, keepdims=True)
+    v0 = verts - c
+    s = np.max(np.abs(v0))
+    s = max(s, 1e-12)
+    return v0 / s * unit_scale
+
+
+def build_mesh(V_np, F_np, device):
+    V = torch.from_numpy(V_np).to(device)
+    F = torch.from_numpy(F_np).to(device)
+    return Meshes(verts=[V], faces=[F])
+
+
+def compute_face_normals(verts: torch.Tensor, faces: torch.Tensor):
+    v0 = verts[faces[:, 0]]
+    v1 = verts[faces[:, 1]]
+    v2 = verts[faces[:, 2]]
+    n = torch.cross(v1 - v0, v2 - v0, dim=1)
+    return torch.nn.functional.normalize(n, dim=1, eps=1e-12)
+
+
+def extract_feature_edges(faces: torch.Tensor, face_normals: torch.Tensor, angle_deg: float):
+    """二面角>=angle_deg 视为特征棱；边界边必取。"""
+    thr = math.cos(math.radians(max(0.0, angle_deg)))
+    e2f = defaultdict(list)
+    F = faces.shape[0]
+    for f in range(F):
+        i, j, k = faces[f].tolist()
+        for a, b in ((i, j), (j, k), (k, i)):
+            e = (a, b) if a < b else (b, a)
+            e2f[e].append(f)
+    feat = []
+    for e, fl in e2f.items():
+        if len(fl) == 1:
+            feat.append(e)
+        elif len(fl) == 2:
+            n0, n1 = face_normals[fl[0]], face_normals[fl[1]]
+            cosv = torch.clamp((n0 * n1).sum(), -1.0, 1.0).item()
+            if cosv <= thr:
+                feat.append(e)
+    return feat
+
+
+def make_camera(view: str, device, dist=2.7):
+    """
+    look_at_view_transform spherical params for engineering views.
+    """
+    if view == "top":
+        # from +Z to origin (view -Z)
+        R, T = look_at_view_transform(dist=dist, elev=90.0, azim=180.0, device=device)
+    elif view == "left":
+        # from -X to origin (view +X)
+        R, T = look_at_view_transform(dist=dist, elev=0.0, azim=270.0, device=device)
+    elif view == "front":
+        # from +Y to origin (view -Y)
+        R, T = look_at_view_transform(dist=dist, elev=0.0, azim=180.0, device=device)
+    else:
+        raise ValueError("view must be one of ['top','left','front']")
+    return OrthographicCameras(R=R, T=T, device=device)
+
+
+def render_silhouette(mesh: Meshes, cameras, image_size=1600):
+    rs = RasterizationSettings(
+        image_size=image_size,
+        blur_radius=1e-6,
+        faces_per_pixel=50,
+        cull_backfaces=True
+    )
+    renderer = MeshRenderer(
+        rasterizer=MeshRasterizer(cameras=cameras, raster_settings=rs),
+        shader=SoftSilhouetteShader(blend_params=BlendParams(sigma=1e-4, gamma=1e-4))
+    )
+    with torch.no_grad():
+        img = renderer(mesh, cameras=cameras)  # (1,H,W,4)
+    return np.clip(img[0, ..., 3].detach().cpu().numpy(), 0.0, 1.0)
+
+
+def raster_fragments(mesh: Meshes, cameras, image_size=1600, faces_per_pixel=1):
+    rs = RasterizationSettings(
+        image_size=image_size,
+        blur_radius=0.0,
+        faces_per_pixel=faces_per_pixel,
+        cull_backfaces=True
+    )
+    rast = MeshRasterizer(cameras=cameras, raster_settings=rs)
+    with torch.no_grad():
+        frags: Fragments = rast(mesh, cameras=cameras)
+    return frags, frags.zbuf[0, ..., 0]
+
+
+def project_points_to_screen(cameras, points_world: torch.Tensor, image_size: int):
+    with torch.no_grad():
+        scr = cameras.transform_points_screen(
+            points_world[None, ...],
+            image_size=((image_size, image_size),)
+        )
+    return scr[0]
+
+
+def edge_visibility_split(edges_idx, verts_world, cameras, zbuf, image_size, eps=1e-4):
+    H = W = image_size
+    vis, hid = [], []
+    scr = project_points_to_screen(cameras, verts_world, image_size)
+    zmin = zbuf.detach().cpu().numpy()
+    for i, j in edges_idx:
+        p0, p1 = scr[i], scr[j]
+        m = 0.5 * (p0 + p1)
+        x = int(np.clip(m[0].item(), 0, W - 1))
+        y = int(np.clip(m[1].item(), 0, H - 1))
+        z_proj = m[2].item()
+        z_ref = zmin[y, x]
+        seg = (p0[0].item(), p0[1].item(), p1[0].item(), p1[1].item())
+        if np.isfinite(z_ref) and (z_proj <= z_ref + eps):
+            vis.append(seg)
+        else:
+            hid.append(seg)
+    return vis, hid
+
+
+def trace_silhouettes(alpha: np.ndarray, threshold=0.5, step=1):
+    contours = measure.find_contours(alpha, level=threshold)
+    polys = []
+    for cnt in contours:
+        if len(cnt) < 8:
+            continue
+        cnt = cnt[::max(1, step)]
+        polys.append(np.stack([cnt[:, 1], cnt[:, 0]], axis=1))  # (x,y)
+    return polys
+
+
+def svg_from_view(out_svg, W, H, silhouettes, edges_vis, edges_hid, stroke=2.0, margin=10, fill="none"):
+    dwg = svgwrite.Drawing(out_svg, size=(W + 2 * margin, H + 2 * margin))
+    dwg.add(dwg.rect(insert=(0, 0), size=(W + 2 * margin, H + 2 * margin), fill="none"))
+
+    # silhouette fill (optional)
+    for poly in silhouettes:
+        if len(poly) < 3:
+            continue
+        path = [f"M {poly[0, 0] + margin:.2f} {poly[0, 1] + margin:.2f}"]
+        for i in range(1, len(poly)):
+            path.append(f"L {poly[i, 0] + margin:.2f} {poly[i, 1] + margin:.2f}")
+        path.append("Z")
+        dwg.add(dwg.path(" ".join(path), fill=fill, stroke="none"))
+
+    # visible edges
+    for (x0, y0, x1, y1) in edges_vis:
+        dwg.add(dwg.line(
+            (x0 + margin, y0 + margin),
+            (x1 + margin, y1 + margin),
+            stroke="black",
+            stroke_width=stroke
+        ))
+
+    # hidden edges
+    for (x0, y0, x1, y1) in edges_hid:
+        dwg.add(dwg.line(
+            (x0 + margin, y0 + margin),
+            (x1 + margin, y1 + margin),
+            stroke="black",
+            stroke_width=max(1.0, 0.75 * stroke),
+            stroke_dasharray=[6, 6],
+            opacity=0.85
+        ))
+
+    dwg.save()
+
+
+def combine_svgs(view1_path, view2_path, view3_path, output_svg, output_image):
+    """
+    横向拼接 3 张 SVG，并额外导出 PNG。
+    """
+    out_dir = os.path.dirname(output_svg)
+    if out_dir:
+        os.makedirs(out_dir, exist_ok=True)
+
+    view1 = st.fromfile(view1_path)
+    view2 = st.fromfile(view2_path)
+    view3 = st.fromfile(view3_path)
+
+    r1 = view1.getroot()
+    r2 = view2.getroot()
+    r3 = view3.getroot()
+
+    w1, h1 = [float(x.replace("px", "")) for x in view1.get_size()]
+    w2, h2 = [float(x.replace("px", "")) for x in view2.get_size()]
+    w3, h3 = [float(x.replace("px", "")) for x in view3.get_size()]
+
+    max_w = max(w1, w2, w3)
+    max_h = max(h1, h2, h3)
+
+    combined_width = max_w * 3 + 40
+    combined_height = max_h + 20
+
+    combined = st.SVGFigure(Unit(combined_width), Unit(combined_height))
+
+    x_offset = 10
+    y_offset = 10
+
+    r1.moveto(x_offset, y_offset)
+    x_offset += max_w + 20
+    r2.moveto(x_offset, y_offset)
+    x_offset += max_w + 20
+    r3.moveto(x_offset, y_offset)
+
+    combined.append([r1, r2, r3])
+    combined.save(output_svg)
+
+    # SVG -> PNG
+    cairosvg.svg2png(url=output_svg, write_to=output_image)
+
+
+def step_to_svg(step_path, out_dir,
+                res: int = 1400, defl: float = 1.5,
+                ang: float = 65.0, stroke: float = 1.3,
+                scale: float = 1.0, no_combine: bool = False,
+                combined_svg: str = None, combined_png: str = None):
+    os.makedirs(out_dir, exist_ok=True)
+    device = autodevice()
+    print(f"[Device] {device}")
+
+    # STEP -> mesh
+    shape = read_step_solid(step_path)
+    V_np, F_np = triangulate(shape, deflection=defl)
+    V_np = normalize_mesh_np(V_np, unit_scale=scale)
+
+    mesh = build_mesh(V_np, F_np, device)
+    verts = mesh.verts_packed()
+    faces = mesh.faces_packed()
+    fn = compute_face_normals(verts, faces)
+    feat_edges = extract_feature_edges(faces, fn, angle_deg=ang)
+
+    view_paths = {}
+    for name in ["top", "left", "front"]:
+        print(f"[View] {name}")
+        cam = make_camera(name, device)
+        alpha = render_silhouette(mesh, cam, image_size=res)
+        _, zbuf = raster_fragments(mesh, cam, image_size=res, faces_per_pixel=1)
+
+        e_vis, e_hid = edge_visibility_split(feat_edges, verts, cam, zbuf, res, eps=1e-4)
+        polys = trace_silhouettes(alpha, threshold=0.5, step=1)
+
+        out_svg = os.path.join(out_dir, f"{name}.svg")
+        svg_from_view(out_svg, res, res, polys, e_vis, e_hid,
+                      stroke=stroke, margin=10, fill="none")
+        view_paths[name] = out_svg
+        print(f"  -> {out_svg} (edges: vis={len(e_vis)}, hid={len(e_hid)}, polys={len(polys)})")
+
+    if no_combine:
+        print("[Done] 3 views exported (no combine).")
+        return None
+
+    combined_svg = combined_svg or os.path.join(out_dir, "combined_views.svg")
+    combined_png = combined_png or os.path.join(out_dir, "combined_views.png")
+
+    # 注意：这里组合顺序按你第二段示例：front / top / left
+    combine_svgs(
+        view1_path=view_paths["front"],
+        view2_path=view_paths["top"],
+        view3_path=view_paths["left"],
+        output_svg=combined_svg,
+        output_image=combined_png
+    )
+    return combined_svg, combined_png
+
+
+if __name__ == "__main__":
+    # step -1
+    glb_result, ply_result = image_to_3d(image=["assets/whiteboard_exported_image.png"])
+    print(f"glb_result : {glb_result}", f"ply_result : {ply_result}")
+
+    # step 0
+    obj_result = glb_to_obj(glb_result)
+    print(f"obj_result : {obj_result}")
+
+    # step 1
+    step_result = obj_to_step(input_obj=obj_result, output_dir="step_output", script_path="1_obj_to_step.py")
+
+    # step 2
+    out_dir = "svg_output"
+    combined_svg, combined_png = step_to_svg(step_path=step_result, out_dir=out_dir)
+    print(f"combined_svg : {combined_svg}", f"combined_png : {combined_png}")
diff --git a/trellis/pipelines/samplers/guidance_interval_mixin.py b/trellis/pipelines/samplers/guidance_interval_mixin.py
new file mode 100644
index 0000000..7074a4d
--- /dev/null
+++ b/trellis/pipelines/samplers/guidance_interval_mixin.py
@@ -0,0 +1,15 @@
+from typing import *
+
+
+class GuidanceIntervalSamplerMixin:
+    """
+    A mixin class for samplers that apply classifier-free guidance with interval.
+    """
+
+    def _inference_model(self, model, x_t, t, cond, neg_cond, cfg_strength, cfg_interval, **kwargs):
+        if cfg_interval[0] <= t <= cfg_interval[1]:
+            pred = super()._inference_model(model, x_t, t, cond, **kwargs)
+            neg_pred = super()._inference_model(model, x_t, t, neg_cond, **kwargs)
+            return (1 + cfg_strength) * pred - cfg_strength * neg_pred
+        else:
+            return super()._inference_model(model, x_t, t, cond, **kwargs)
diff --git a/trellis/renderers/gaussian_render.py b/trellis/renderers/gaussian_render.py
new file mode 100644
index 0000000..57108e3
--- /dev/null
+++ b/trellis/renderers/gaussian_render.py
@@ -0,0 +1,231 @@
+#
+# Copyright (C) 2023, Inria
+# GRAPHDECO research group, https://team.inria.fr/graphdeco
+# All rights reserved.
+#
+# This software is free for non-commercial, research and evaluation use 
+# under the terms of the LICENSE.md file.
+#
+# For inquiries contact  george.drettakis@inria.fr
+#
+
+import torch
+import math
+from easydict import EasyDict as edict
+import numpy as np
+from ..representations.gaussian import Gaussian
+from .sh_utils import eval_sh
+import torch.nn.functional as F
+from easydict import EasyDict as edict
+
+
+def intrinsics_to_projection(
+        intrinsics: torch.Tensor,
+        near: float,
+        far: float,
+    ) -> torch.Tensor:
+    """
+    OpenCV intrinsics to OpenGL perspective matrix
+
+    Args:
+        intrinsics (torch.Tensor): [3, 3] OpenCV intrinsics matrix
+        near (float): near plane to clip
+        far (float): far plane to clip
+    Returns:
+        (torch.Tensor): [4, 4] OpenGL perspective matrix
+    """
+    fx, fy = intrinsics[0, 0], intrinsics[1, 1]
+    cx, cy = intrinsics[0, 2], intrinsics[1, 2]
+    ret = torch.zeros((4, 4), dtype=intrinsics.dtype, device=intrinsics.device)
+    ret[0, 0] = 2 * fx
+    ret[1, 1] = 2 * fy
+    ret[0, 2] = 2 * cx - 1
+    ret[1, 2] = - 2 * cy + 1
+    ret[2, 2] = far / (far - near)
+    ret[2, 3] = near * far / (near - far)
+    ret[3, 2] = 1.
+    return ret
+
+
+def render(viewpoint_camera, pc : Gaussian, pipe, bg_color : torch.Tensor, scaling_modifier = 1.0, override_color = None):
+    """
+    Render the scene. 
+    
+    Background tensor (bg_color) must be on GPU!
+    """
+    # lazy import
+    if 'GaussianRasterizer' not in globals():
+        from diff_gaussian_rasterization import GaussianRasterizer, GaussianRasterizationSettings
+    
+    # Create zero tensor. We will use it to make pytorch return gradients of the 2D (screen-space) means
+    screenspace_points = torch.zeros_like(pc.get_xyz, dtype=pc.get_xyz.dtype, requires_grad=True, device="cuda") + 0
+    try:
+        screenspace_points.retain_grad()
+    except:
+        pass
+    # Set up rasterization configuration
+    tanfovx = math.tan(viewpoint_camera.FoVx * 0.5)
+    tanfovy = math.tan(viewpoint_camera.FoVy * 0.5)
+    
+    kernel_size = pipe.kernel_size
+    subpixel_offset = torch.zeros((int(viewpoint_camera.image_height), int(viewpoint_camera.image_width), 2), dtype=torch.float32, device="cuda")
+
+    raster_settings = GaussianRasterizationSettings(
+        image_height=int(viewpoint_camera.image_height),
+        image_width=int(viewpoint_camera.image_width),
+        tanfovx=tanfovx,
+        tanfovy=tanfovy,
+        kernel_size=kernel_size,
+        subpixel_offset=subpixel_offset,
+        bg=bg_color,
+        scale_modifier=scaling_modifier,
+        viewmatrix=viewpoint_camera.world_view_transform,
+        projmatrix=viewpoint_camera.full_proj_transform,
+        sh_degree=pc.active_sh_degree,
+        campos=viewpoint_camera.camera_center,
+        prefiltered=False,
+        debug=pipe.debug
+    )
+    
+    rasterizer = GaussianRasterizer(raster_settings=raster_settings)
+
+    means3D = pc.get_xyz
+    means2D = screenspace_points
+    opacity = pc.get_opacity
+
+    # If precomputed 3d covariance is provided, use it. If not, then it will be computed from
+    # scaling / rotation by the rasterizer.
+    scales = None
+    rotations = None
+    cov3D_precomp = None
+    if pipe.compute_cov3D_python:
+        cov3D_precomp = pc.get_covariance(scaling_modifier)
+    else:
+        scales = pc.get_scaling
+        rotations = pc.get_rotation
+
+    # If precomputed colors are provided, use them. Otherwise, if it is desired to precompute colors
+    # from SHs in Python, do it. If not, then SH -> RGB conversion will be done by rasterizer.
+    shs = None
+    colors_precomp = None
+    if override_color is None:
+        if pipe.convert_SHs_python:
+            shs_view = pc.get_features.transpose(1, 2).view(-1, 3, (pc.max_sh_degree+1)**2)
+            dir_pp = (pc.get_xyz - viewpoint_camera.camera_center.repeat(pc.get_features.shape[0], 1))
+            dir_pp_normalized = dir_pp/dir_pp.norm(dim=1, keepdim=True)
+            sh2rgb = eval_sh(pc.active_sh_degree, shs_view, dir_pp_normalized)
+            colors_precomp = torch.clamp_min(sh2rgb + 0.5, 0.0)
+        else:
+            shs = pc.get_features
+    else:
+        colors_precomp = override_color
+
+    # Rasterize visible Gaussians to image, obtain their radii (on screen). 
+    rendered_image, radii = rasterizer(
+        means3D = means3D,
+        means2D = means2D,
+        shs = shs,
+        colors_precomp = colors_precomp,
+        opacities = opacity,
+        scales = scales,
+        rotations = rotations,
+        cov3D_precomp = cov3D_precomp
+    )
+
+    # Those Gaussians that were frustum culled or had a radius of 0 were not visible.
+    # They will be excluded from value updates used in the splitting criteria.
+    return edict({"render": rendered_image,
+            "viewspace_points": screenspace_points,
+            "visibility_filter" : radii > 0,
+            "radii": radii})
+
+
+class GaussianRenderer:
+    """
+    Renderer for the Voxel representation.
+
+    Args:
+        rendering_options (dict): Rendering options.
+    """
+
+    def __init__(self, rendering_options={}) -> None:
+        self.pipe = edict({
+            "kernel_size": 0.1,
+            "convert_SHs_python": False,
+            "compute_cov3D_python": False,
+            "scale_modifier": 1.0,
+            "debug": False
+        })
+        self.rendering_options = edict({
+            "resolution": None,
+            "near": None,
+            "far": None,
+            "ssaa": 1,
+            "bg_color": 'random',
+        })
+        self.rendering_options.update(rendering_options)
+        self.bg_color = None
+    
+    def render(
+            self,
+            gausssian: Gaussian,
+            extrinsics: torch.Tensor,
+            intrinsics: torch.Tensor,
+            colors_overwrite: torch.Tensor = None
+        ) -> edict:
+        """
+        Render the gausssian.
+
+        Args:
+            gaussian : gaussianmodule
+            extrinsics (torch.Tensor): (4, 4) camera extrinsics
+            intrinsics (torch.Tensor): (3, 3) camera intrinsics
+            colors_overwrite (torch.Tensor): (N, 3) override color
+
+        Returns:
+            edict containing:
+                color (torch.Tensor): (3, H, W) rendered color image
+        """
+        resolution = self.rendering_options["resolution"]
+        near = self.rendering_options["near"]
+        far = self.rendering_options["far"]
+        ssaa = self.rendering_options["ssaa"]
+        
+        if self.rendering_options["bg_color"] == 'random':
+            self.bg_color = torch.zeros(3, dtype=torch.float32, device="cuda")
+            if np.random.rand() < 0.5:
+                self.bg_color += 1
+        else:
+            self.bg_color = torch.tensor(self.rendering_options["bg_color"], dtype=torch.float32, device="cuda")
+
+        view = extrinsics
+        perspective = intrinsics_to_projection(intrinsics, near, far)
+        camera = torch.inverse(view)[:3, 3]
+        focalx = intrinsics[0, 0]
+        focaly = intrinsics[1, 1]
+        fovx = 2 * torch.atan(0.5 / focalx)
+        fovy = 2 * torch.atan(0.5 / focaly)
+            
+        camera_dict = edict({
+            "image_height": resolution * ssaa,
+            "image_width": resolution * ssaa,
+            "FoVx": fovx,
+            "FoVy": fovy,
+            "znear": near,
+            "zfar": far,
+            "world_view_transform": view.T.contiguous(),
+            "projection_matrix": perspective.T.contiguous(),
+            "full_proj_transform": (perspective @ view).T.contiguous(),
+            "camera_center": camera
+        })
+
+        # Render
+        render_ret = render(camera_dict, gausssian, self.pipe, self.bg_color, override_color=colors_overwrite, scaling_modifier=self.pipe.scale_modifier)
+
+        if ssaa > 1:
+            render_ret.render = F.interpolate(render_ret.render[None], size=(resolution, resolution), mode='bilinear', align_corners=False, antialias=True).squeeze()
+            
+        ret = edict({
+            'color': render_ret['render']
+        })
+        return ret
diff --git a/trellis/representations/gaussian/general_utils.py b/trellis/representations/gaussian/general_utils.py
new file mode 100644
index 0000000..541c082
--- /dev/null
+++ b/trellis/representations/gaussian/general_utils.py
@@ -0,0 +1,133 @@
+#
+# Copyright (C) 2023, Inria
+# GRAPHDECO research group, https://team.inria.fr/graphdeco
+# All rights reserved.
+#
+# This software is free for non-commercial, research and evaluation use 
+# under the terms of the LICENSE.md file.
+#
+# For inquiries contact  george.drettakis@inria.fr
+#
+
+import torch
+import sys
+from datetime import datetime
+import numpy as np
+import random
+
+def inverse_sigmoid(x):
+    return torch.log(x/(1-x))
+
+def PILtoTorch(pil_image, resolution):
+    resized_image_PIL = pil_image.resize(resolution)
+    resized_image = torch.from_numpy(np.array(resized_image_PIL)) / 255.0
+    if len(resized_image.shape) == 3:
+        return resized_image.permute(2, 0, 1)
+    else:
+        return resized_image.unsqueeze(dim=-1).permute(2, 0, 1)
+
+def get_expon_lr_func(
+    lr_init, lr_final, lr_delay_steps=0, lr_delay_mult=1.0, max_steps=1000000
+):
+    """
+    Copied from Plenoxels
+
+    Continuous learning rate decay function. Adapted from JaxNeRF
+    The returned rate is lr_init when step=0 and lr_final when step=max_steps, and
+    is log-linearly interpolated elsewhere (equivalent to exponential decay).
+    If lr_delay_steps>0 then the learning rate will be scaled by some smooth
+    function of lr_delay_mult, such that the initial learning rate is
+    lr_init*lr_delay_mult at the beginning of optimization but will be eased back
+    to the normal learning rate when steps>lr_delay_steps.
+    :param conf: config subtree 'lr' or similar
+    :param max_steps: int, the number of steps during optimization.
+    :return HoF which takes step as input
+    """
+
+    def helper(step):
+        if step < 0 or (lr_init == 0.0 and lr_final == 0.0):
+            # Disable this parameter
+            return 0.0
+        if lr_delay_steps > 0:
+            # A kind of reverse cosine decay.
+            delay_rate = lr_delay_mult + (1 - lr_delay_mult) * np.sin(
+                0.5 * np.pi * np.clip(step / lr_delay_steps, 0, 1)
+            )
+        else:
+            delay_rate = 1.0
+        t = np.clip(step / max_steps, 0, 1)
+        log_lerp = np.exp(np.log(lr_init) * (1 - t) + np.log(lr_final) * t)
+        return delay_rate * log_lerp
+
+    return helper
+
+def strip_lowerdiag(L):
+    uncertainty = torch.zeros((L.shape[0], 6), dtype=torch.float, device="cuda")
+
+    uncertainty[:, 0] = L[:, 0, 0]
+    uncertainty[:, 1] = L[:, 0, 1]
+    uncertainty[:, 2] = L[:, 0, 2]
+    uncertainty[:, 3] = L[:, 1, 1]
+    uncertainty[:, 4] = L[:, 1, 2]
+    uncertainty[:, 5] = L[:, 2, 2]
+    return uncertainty
+
+def strip_symmetric(sym):
+    return strip_lowerdiag(sym)
+
+def build_rotation(r):
+    norm = torch.sqrt(r[:,0]*r[:,0] + r[:,1]*r[:,1] + r[:,2]*r[:,2] + r[:,3]*r[:,3])
+
+    q = r / norm[:, None]
+
+    R = torch.zeros((q.size(0), 3, 3), device='cuda')
+
+    r = q[:, 0]
+    x = q[:, 1]
+    y = q[:, 2]
+    z = q[:, 3]
+
+    R[:, 0, 0] = 1 - 2 * (y*y + z*z)
+    R[:, 0, 1] = 2 * (x*y - r*z)
+    R[:, 0, 2] = 2 * (x*z + r*y)
+    R[:, 1, 0] = 2 * (x*y + r*z)
+    R[:, 1, 1] = 1 - 2 * (x*x + z*z)
+    R[:, 1, 2] = 2 * (y*z - r*x)
+    R[:, 2, 0] = 2 * (x*z - r*y)
+    R[:, 2, 1] = 2 * (y*z + r*x)
+    R[:, 2, 2] = 1 - 2 * (x*x + y*y)
+    return R
+
+def build_scaling_rotation(s, r):
+    L = torch.zeros((s.shape[0], 3, 3), dtype=torch.float, device="cuda")
+    R = build_rotation(r)
+
+    L[:,0,0] = s[:,0]
+    L[:,1,1] = s[:,1]
+    L[:,2,2] = s[:,2]
+
+    L = R @ L
+    return L
+
+def safe_state(silent):
+    old_f = sys.stdout
+    class F:
+        def __init__(self, silent):
+            self.silent = silent
+
+        def write(self, x):
+            if not self.silent:
+                if x.endswith("\n"):
+                    old_f.write(x.replace("\n", " [{}]\n".format(str(datetime.now().strftime("%d/%m %H:%M:%S")))))
+                else:
+                    old_f.write(x)
+
+        def flush(self):
+            old_f.flush()
+
+    sys.stdout = F(silent)
+
+    random.seed(0)
+    np.random.seed(0)
+    torch.manual_seed(0)
+    torch.cuda.set_device(torch.device("cuda:0"))
diff --git a/trellis/trainers/flow_matching/mixins/image_conditioned.py b/trellis/trainers/flow_matching/mixins/image_conditioned.py
new file mode 100644
index 0000000..be18d64
--- /dev/null
+++ b/trellis/trainers/flow_matching/mixins/image_conditioned.py
@@ -0,0 +1,93 @@
+from typing import *
+import torch
+import torch.nn.functional as F
+from torchvision import transforms
+import numpy as np
+from PIL import Image
+
+from ....utils import dist_utils
+
+
+class ImageConditionedMixin:
+    """
+    Mixin for image-conditioned models.
+    
+    Args:
+        image_cond_model: The image conditioning model.
+    """
+    def __init__(self, *args, image_cond_model: str = 'dinov2_vitl14_reg', **kwargs):
+        super().__init__(*args, **kwargs)
+        self.image_cond_model_name = image_cond_model
+        self.image_cond_model = None     # the model is init lazily
+        
+    @staticmethod
+    def prepare_for_training(image_cond_model: str, **kwargs):
+        """
+        Prepare for training.
+        """
+        if hasattr(super(ImageConditionedMixin, ImageConditionedMixin), 'prepare_for_training'):
+            super(ImageConditionedMixin, ImageConditionedMixin).prepare_for_training(**kwargs)
+        # download the model
+        torch.hub.load('facebookresearch/dinov2', image_cond_model, pretrained=True)
+        
+    def _init_image_cond_model(self):
+        """
+        Initialize the image conditioning model.
+        """
+        with dist_utils.local_master_first():
+            dinov2_model = torch.hub.load('facebookresearch/dinov2', self.image_cond_model_name, pretrained=True)
+        dinov2_model.eval().cuda()
+        transform = transforms.Compose([
+            transforms.Normalize(mean=[0.485, 0.456, 0.406], std=[0.229, 0.224, 0.225]),
+        ])
+        self.image_cond_model = {
+            'model': dinov2_model,
+            'transform': transform,
+        }
+    
+    @torch.no_grad()
+    def encode_image(self, image: Union[torch.Tensor, List[Image.Image]]) -> torch.Tensor:
+        """
+        Encode the image.
+        """
+        if isinstance(image, torch.Tensor):
+            assert image.ndim == 4, "Image tensor should be batched (B, C, H, W)"
+        elif isinstance(image, list):
+            assert all(isinstance(i, Image.Image) for i in image), "Image list should be list of PIL images"
+            image = [i.resize((518, 518), Image.LANCZOS) for i in image]
+            image = [np.array(i.convert('RGB')).astype(np.float32) / 255 for i in image]
+            image = [torch.from_numpy(i).permute(2, 0, 1).float() for i in image]
+            image = torch.stack(image).cuda()
+        else:
+            raise ValueError(f"Unsupported type of image: {type(image)}")
+        
+        if self.image_cond_model is None:
+            self._init_image_cond_model()
+        image = self.image_cond_model['transform'](image).cuda()
+        features = self.image_cond_model['model'](image, is_training=True)['x_prenorm']
+        patchtokens = F.layer_norm(features, features.shape[-1:])
+        return patchtokens
+        
+    def get_cond(self, cond, **kwargs):
+        """
+        Get the conditioning data.
+        """
+        cond = self.encode_image(cond)
+        kwargs['neg_cond'] = torch.zeros_like(cond)
+        cond = super().get_cond(cond, **kwargs)
+        return cond
+    
+    def get_inference_cond(self, cond, **kwargs):
+        """
+        Get the conditioning data for inference.
+        """
+        cond = self.encode_image(cond)
+        kwargs['neg_cond'] = torch.zeros_like(cond)
+        cond = super().get_inference_cond(cond, **kwargs)
+        return cond
+
+    def vis_cond(self, cond, **kwargs):
+        """
+        Visualize the conditioning data.
+        """
+        return {'image': {'value': cond, 'type': 'image'}}
diff --git a/trellis/utils/general_utils.py b/trellis/utils/general_utils.py
new file mode 100644
index 0000000..c0d765f
--- /dev/null
+++ b/trellis/utils/general_utils.py
@@ -0,0 +1,202 @@
+import re
+import numpy as np
+import cv2
+import torch
+import contextlib
+
+
+# Dictionary utils
+def _dict_merge(dicta, dictb, prefix=''):
+    """
+    Merge two dictionaries.
+    """
+    assert isinstance(dicta, dict), 'input must be a dictionary'
+    assert isinstance(dictb, dict), 'input must be a dictionary'
+    dict_ = {}
+    all_keys = set(dicta.keys()).union(set(dictb.keys()))
+    for key in all_keys:
+        if key in dicta.keys() and key in dictb.keys():
+            if isinstance(dicta[key], dict) and isinstance(dictb[key], dict):
+                dict_[key] = _dict_merge(dicta[key], dictb[key], prefix=f'{prefix}.{key}')
+            else:
+                raise ValueError(f'Duplicate key {prefix}.{key} found in both dictionaries. Types: {type(dicta[key])}, {type(dictb[key])}')
+        elif key in dicta.keys():
+            dict_[key] = dicta[key]
+        else:
+            dict_[key] = dictb[key]
+    return dict_
+
+
+def dict_merge(dicta, dictb):
+    """
+    Merge two dictionaries.
+    """
+    return _dict_merge(dicta, dictb, prefix='')
+
+
+def dict_foreach(dic, func, special_func={}):
+    """
+    Recursively apply a function to all non-dictionary leaf values in a dictionary.
+    """
+    assert isinstance(dic, dict), 'input must be a dictionary'
+    for key in dic.keys():
+        if isinstance(dic[key], dict):
+            dic[key] = dict_foreach(dic[key], func)
+        else:
+            if key in special_func.keys():
+                dic[key] = special_func[key](dic[key])
+            else:
+                dic[key] = func(dic[key])
+    return dic
+
+
+def dict_reduce(dicts, func, special_func={}):
+    """
+    Reduce a list of dictionaries. Leaf values must be scalars.
+    """
+    assert isinstance(dicts, list), 'input must be a list of dictionaries'
+    assert all([isinstance(d, dict) for d in dicts]), 'input must be a list of dictionaries'
+    assert len(dicts) > 0, 'input must be a non-empty list of dictionaries'
+    all_keys = set([key for dict_ in dicts for key in dict_.keys()])
+    reduced_dict = {}
+    for key in all_keys:
+        vlist = [dict_[key] for dict_ in dicts if key in dict_.keys()]
+        if isinstance(vlist[0], dict):
+            reduced_dict[key] = dict_reduce(vlist, func, special_func)
+        else:
+            if key in special_func.keys():
+                reduced_dict[key] = special_func[key](vlist)
+            else:
+                reduced_dict[key] = func(vlist)
+    return reduced_dict
+
+
+def dict_any(dic, func):
+    """
+    Recursively apply a function to all non-dictionary leaf values in a dictionary.
+    """
+    assert isinstance(dic, dict), 'input must be a dictionary'
+    for key in dic.keys():
+        if isinstance(dic[key], dict):
+            if dict_any(dic[key], func):
+                return True
+        else:
+            if func(dic[key]):
+                return True
+    return False
+
+
+def dict_all(dic, func):
+    """
+    Recursively apply a function to all non-dictionary leaf values in a dictionary.
+    """
+    assert isinstance(dic, dict), 'input must be a dictionary'
+    for key in dic.keys():
+        if isinstance(dic[key], dict):
+            if not dict_all(dic[key], func):
+                return False
+        else:
+            if not func(dic[key]):
+                return False
+    return True
+
+
+def dict_flatten(dic, sep='.'):
+    """
+    Flatten a nested dictionary into a dictionary with no nested dictionaries.
+    """
+    assert isinstance(dic, dict), 'input must be a dictionary'
+    flat_dict = {}
+    for key in dic.keys():
+        if isinstance(dic[key], dict):
+            sub_dict = dict_flatten(dic[key], sep=sep)
+            for sub_key in sub_dict.keys():
+                flat_dict[str(key) + sep + str(sub_key)] = sub_dict[sub_key]
+        else:
+            flat_dict[key] = dic[key]
+    return flat_dict
+
+
+# Context utils
+@contextlib.contextmanager
+def nested_contexts(*contexts):
+    with contextlib.ExitStack() as stack:
+        for ctx in contexts:
+            stack.enter_context(ctx())
+        yield
+
+
+# Image utils
+def make_grid(images, nrow=None, ncol=None, aspect_ratio=None):
+    num_images = len(images)
+    if nrow is None and ncol is None:
+        if aspect_ratio is not None:
+            nrow = int(np.round(np.sqrt(num_images / aspect_ratio)))
+        else:
+            nrow = int(np.sqrt(num_images))
+        ncol = (num_images + nrow - 1) // nrow
+    elif nrow is None and ncol is not None:
+        nrow = (num_images + ncol - 1) // ncol
+    elif nrow is not None and ncol is None:
+        ncol = (num_images + nrow - 1) // nrow
+    else:
+        assert nrow * ncol >= num_images, 'nrow * ncol must be greater than or equal to the number of images'
+    
+    if images[0].ndim == 2:
+        grid = np.zeros((nrow * images[0].shape[0], ncol * images[0].shape[1]), dtype=images[0].dtype)
+    else:
+        grid = np.zeros((nrow * images[0].shape[0], ncol * images[0].shape[1], images[0].shape[2]), dtype=images[0].dtype)
+    for i, img in enumerate(images):
+        row = i // ncol
+        col = i % ncol
+        grid[row * img.shape[0]:(row + 1) * img.shape[0], col * img.shape[1]:(col + 1) * img.shape[1]] = img
+    return grid
+
+
+def notes_on_image(img, notes=None):
+    img = np.pad(img, ((0, 32), (0, 0), (0, 0)), 'constant', constant_values=0)
+    img = cv2.cvtColor(img, cv2.COLOR_RGB2BGR)
+    if notes is not None:
+        img = cv2.putText(img, notes, (0, img.shape[0] - 4), cv2.FONT_HERSHEY_SIMPLEX, 1, (255, 255, 255), 1)
+    img = cv2.cvtColor(img, cv2.COLOR_BGR2RGB)
+    return img
+
+
+def save_image_with_notes(img, path, notes=None):
+    """
+    Save an image with notes.
+    """
+    if isinstance(img, torch.Tensor):
+        img = img.cpu().numpy().transpose(1, 2, 0)
+    if img.dtype == np.float32 or img.dtype == np.float64:
+        img = np.clip(img * 255, 0, 255).astype(np.uint8)
+    img = notes_on_image(img, notes)
+    cv2.imwrite(path, cv2.cvtColor(img, cv2.COLOR_RGB2BGR))
+
+
+# debug utils
+
+def atol(x, y):
+    """
+    Absolute tolerance.
+    """
+    return torch.abs(x - y)
+
+
+def rtol(x, y):
+    """
+    Relative tolerance.
+    """
+    return torch.abs(x - y) / torch.clamp_min(torch.maximum(torch.abs(x), torch.abs(y)), 1e-12)
+
+
+# print utils
+def indent(s, n=4):
+    """
+    Indent a string.
+    """
+    lines = s.split('\n')
+    for i in range(1, len(lines)):
+        lines[i] = ' ' * n + lines[i]
+    return '\n'.join(lines)
+
diff --git a/trellis/utils/grad_clip_utils.py b/trellis/utils/grad_clip_utils.py
new file mode 100644
index 0000000..990a435
--- /dev/null
+++ b/trellis/utils/grad_clip_utils.py
@@ -0,0 +1,81 @@
+from typing import *
+import torch
+import numpy as np
+import torch.utils
+
+
+class AdaptiveGradClipper:
+    """
+    Adaptive gradient clipping for training.
+    """
+    def __init__(
+        self,
+        max_norm=None,
+        clip_percentile=95.0,
+        buffer_size=1000,
+    ):
+        self.max_norm = max_norm
+        self.clip_percentile = clip_percentile
+        self.buffer_size = buffer_size
+        
+        self._grad_norm = np.zeros(buffer_size, dtype=np.float32)
+        self._max_norm = max_norm
+        self._buffer_ptr = 0
+        self._buffer_length = 0
+
+    def __repr__(self):
+        return f'AdaptiveGradClipper(max_norm={self.max_norm}, clip_percentile={self.clip_percentile})'
+        
+    def state_dict(self):
+        return {
+            'grad_norm': self._grad_norm,
+            'max_norm': self._max_norm,
+            'buffer_ptr': self._buffer_ptr,
+            'buffer_length': self._buffer_length,
+        }
+
+    def load_state_dict(self, state_dict):
+        self._grad_norm = state_dict['grad_norm']
+        self._max_norm = state_dict['max_norm']
+        self._buffer_ptr = state_dict['buffer_ptr']
+        self._buffer_length = state_dict['buffer_length']
+
+    def log(self):
+        return {
+            'max_norm': self._max_norm,
+        }
+
+    def __call__(self, parameters, norm_type=2.0, error_if_nonfinite=False, foreach=None):
+        """Clip the gradient norm of an iterable of parameters.
+
+        The norm is computed over all gradients together, as if they were
+        concatenated into a single vector. Gradients are modified in-place.
+
+        Args:
+            parameters (Iterable[Tensor] or Tensor): an iterable of Tensors or a
+                single Tensor that will have gradients normalized
+            norm_type (float): type of the used p-norm. Can be ``'inf'`` for
+                infinity norm.
+            error_if_nonfinite (bool): if True, an error is thrown if the total
+                norm of the gradients from :attr:`parameters` is ``nan``,
+                ``inf``, or ``-inf``. Default: False (will switch to True in the future)
+            foreach (bool): use the faster foreach-based implementation.
+                If ``None``, use the foreach implementation for CUDA and CPU native tensors and silently
+                fall back to the slow implementation for other device types.
+                Default: ``None``
+
+        Returns:
+            Total norm of the parameter gradients (viewed as a single vector).
+        """
+        max_norm = self._max_norm if self._max_norm is not None else float('inf')
+        grad_norm = torch.nn.utils.clip_grad_norm_(parameters, max_norm=max_norm, norm_type=norm_type, error_if_nonfinite=error_if_nonfinite, foreach=foreach)
+        
+        if torch.isfinite(grad_norm):
+            self._grad_norm[self._buffer_ptr] = grad_norm
+            self._buffer_ptr = (self._buffer_ptr + 1) % self.buffer_size
+            self._buffer_length = min(self._buffer_length + 1, self.buffer_size)
+            if self._buffer_length == self.buffer_size:
+                self._max_norm = np.percentile(self._grad_norm, self.clip_percentile)
+                self._max_norm = min(self._max_norm, self.max_norm) if self.max_norm is not None else self._max_norm
+        
+        return grad_norm
\ No newline at end of file