DreamPartGenSemantically Grounded Part-Level 3D Generation via Collaborative Latent Denoising

PLAN Lab · University of Illinois Urbana-Champaign

ECCV 2026

TL;DR

We introduce DreamPartGen, a text-to-3D framework that generates objects as distinct, meaningful parts. DreamPartGen coordinates each part’s geometry and appearance with the relationships described in language, producing coherent assemblies that support part editing, articulated objects, and mini-scene generation.

Interactive 3D Models

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Abstract

Understanding and generating 3D objects as compositions of meaningful parts is fundamental to human perception and reasoning. However, most text-to-3D methods overlook the semantic and functional structure of parts. While recent part-aware approaches introduce decomposition, they remain largely geometry-focused, lacking semantic grounding and failing to model how parts align with textual descriptions or their inter-part relations. We propose DreamPartGen, a framework for semantically grounded, part-aware text-to-3D generation. DreamPartGen introduces Duplex Part Latents (DPLs) that jointly model each part's geometry and appearance, and Relational Semantic Latents (RSLs) that capture inter-part dependencies derived from language. A synchronized co-denoising process enforces mutual geometric and semantic consistency, enabling coherent, interpretable, and text-aligned 3D synthesis. Across multiple benchmarks, DreamPartGen delivers state-of-the-art performance in geometric fidelity and text-shape alignment.

Contributions

  • DreamPartGen unifies geometric, visual, and relational reasoning. We introduce a language-grounded collaborative diffusion framework for coherent and interpretable part-level text-to-3D synthesis. Persistent language-derived relational semantic latents remain active throughout denoising, rather than using text only as a one-shot condition.
  • Duplex Part Latents and Relational Semantic Latents encode complementary information. DPLs encode modular, disentangled part geometry and appearance, while RSLs provide text-derived local refinements and global planning signals. Synchronized co-denoising through intra-part and inter-part attention maintains geometry–appearance alignment and guides consistent part assembly.
  • PartRel3D provides explicit supervision for inter-part relations. We curate a large-scale relational dataset with 300K canonicalized functional and spatial triplets across 175 object categories. These annotations connect part geometry, appearance, and language through relations such as support, attach, hinge, above, touching, and aligned-with.
  • Experiments demonstrate coherent and controllable part-aware generation. DreamPartGen achieves state-of-the-art performance across the reported benchmarks, with gains in geometric fidelity, text–shape alignment, and controllable part-level synthesis.

DreamPartGen Method

Semantically Grounded Part-Level 3D Generation

DreamPartGen jointly refines part geometry, appearance, and language-derived relationships to generate coherent 3D objects from text.

DreamPartGen examples of part-aware text-to-3D synthesis, part editing, articulated objects, and mini-scenes.
Part-aware text-to-3D generation, part editing, articulated objects, and mini-scene generation.

DreamPartGen treats part-based 3D generation as a collaborative diffusion process. Geometric and visual representations are refined together with language-derived relationships, so individual parts remain consistent with both the prompt and the assembled object.

DreamPartGen synchronizes geometry, appearance, and language-derived relational latents.
Synchronized denoising aligns each part’s geometry and appearance with local and global semantic relationships.
Duplex Part Latents (DPLs)
These latents encode each part’s geometry and appearance in modular, disentangled representations. They preserve the correspondence between the 3D part and its visual features.
Relational Semantic Latents (RSLs)
These compact, text-derived tokens carry local refinements and global planning signals, including how parts should relate to one another. They remain active throughout denoising.
Synchronized co-denoising
Intra-part attention aligns geometry and appearance within each part. Inter-part attention coordinates relationships across parts, allowing language to guide a coherent assembly.

PartRel3D Dataset

We introduce PartRel3D, a large-scale, relationally annotated part dataset that links part geometry, appearance, and language through explicit functional and spatial relationships. Each object is augmented with canonicalized triplets that encode both functional dependencies (e.g., support, attach, hinge) and spatial arrangements (e.g., above, touching, aligned-with), providing large-scale supervision of assembly-level semantics in 3D.

300K
Canonicalized functional and spatial triplets
175
Object categories
PartRel3D annotates functional and spatial relations between object parts.
PartRel3D links object parts through functional dependencies and spatial relationships.

Quantitative Results

DreamPartGen achieves the lowest CD and EMD on all four generation benchmarks and the strongest text–shape alignment at both object and part levels.

Object generation

Object generation across four benchmarks. Lower scores are better. Best results are bold; second-best results are underlined.

Object generation
Method Objaverse ShapeNet ABO PartRel3D
CD ↓ EMD ↓ IoU ↓ CD ↓ EMD ↓ IoU ↓ CD ↓ EMD ↓ IoU ↓ CD ↓ EMD ↓ IoU ↓
Trellis 0.361 1.320 — 0.549 1.482 — 0.287 0.933 — 0.532 1.526 —
CLAY 0.318 1.245 — 0.527 1.503 — 0.321 1.022 — 0.410 1.646 —
HoloPart 0.334 1.298 0.494 0.478 1.354 0.542 0.269 0.911 0.529 0.355 1.623 0.716
PartCrafter 0.278 1.107 0.453 0.451 1.252 0.499 0.266 0.905 0.505 0.371 1.474 0.700
DreamPartGen (Ours) 0.141 0.810 0.359 0.222 0.967 0.503 0.101 0.531 0.404 0.081 0.412 0.304

Text–shape alignment

Text–shape alignment at object and part levels. Higher scores are better. Best results are bold; second-best results are underlined.

Text–shape alignment
Method CLIP(N-T) ↑ CLIP(I-T) ↑ ULIP-T ↑
Object-level
Trellis 0.192 0.214 0.164
CLAY 0.194 0.216 0.156
HoloPart 0.186 0.206 0.155
PartCrafter 0.187 0.207 0.162
DreamPartGen 0.235 0.264 0.197
Part-level
Trellis 0.106 0.122 0.091
CLAY 0.112 0.128 0.096
HoloPart 0.130 0.141 0.113
PartCrafter 0.125 0.145 0.109
DreamPartGen 0.179 0.200 0.153

Qualitative Results

Part Editing

“A chef’s hat”

“A Christmas hat”

“A clown hat”

“A top hat”

“A shark hat”

“A witch’s hat”

Mini-Scene

Qualitative comparison of generated object parts across methods.
Qualitative comparison on part-level 3D generation. Across diverse object categories, DreamPartGen yields the most faithful decompositions, preserving clear part boundaries, correct topology, and consistent spatial alignment.

Generation Samples

Each pair shows the generated object on the left and its part decomposition on the right. Use the video controls to inspect each example.

BibTeX

@inproceedings{yu2026dreampartgen,
  title={DreamPartGen: Semantically Grounded Part-Level 3D Generation via Collaborative Latent Denoising},
  author={Yu, Tianjiao and Li, Xinzhuo and Wahed, Muntasir and Xiong, Jerry and Shen, Yifan and Shen, Ying and Lourentzou, Ismini},
  booktitle={European Conference on Computer Vision (ECCV)},
  year={2026}
}
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