Generating photorealistic 3D hand-object interactions (HOIs) from text is important for applications like robotic grasping and AR/VR content creation. In practice, however, achieving both visual fidelity and physical plausibility remains difficult, as mesh extraction from text-generated Gaussians is inherently ill-posed and the resulting meshes are often unreliable for physics-based optimization. We present THOM, a training-free framework that generates physically plausible 3D HOI meshes directly from text prompts, without requiring template object meshes. THOM follows a two-stage pipeline: it first generates hand and object Gaussians guided by text, and then refines their interaction using physics-based optimization. To enable reliable interaction modeling, we introduce a mesh extraction method with an explicit vertex-to-Gaussian mapping, which enables topology-aware regularization. We further improve physical plausibility through contact-aware optimization and vision-language model (VLM)-guided translation refinement. Extensive experiments show that THOM produces high-quality HOIs with strong text alignment, visual realism, and interaction plausibility.
Figures & tables
Figure 2: Overall pipeline of THOM. In the first stage, object and hand Gaussians are separately generated from the text prompts. During the second stage, we jointly refine the HOI Gaussians and HOI parameters. At HOI initialization, we refine the hand translation with VLM-guided refinement. During HOI parameters optimization, we introduce physics-based optimization via distance-adaptive contact losses and reposition loss. For both the first and the second stage, Laplacian regularization is applied for topological consistency.
Table 1: Comparison with state-of-the-art text-to-3D and text-to-3D human-object interaction generation methods. *: Adapted to generate hand-object interactions.
Figure 4: Qualitative comparison with human-object interaction methods. *: Adapted to generate hand-object interactions.
Method
Max. pene. ↓
Mean. pene. ↓
Contact ratio ↑
Disp. ↓
G-HOP
1.30 ×10−2
9.52 ×10−3
0.15
1.00
Text2HOI
5.16 ×10−4
2.28 ×10−4
0.98
0.25
Ours
2.20 ×10−5
1.24 ×10−5
0.95
0.20
Table 2: Physics and simulation evaluation results with learning-based HOI generation methods.
w/o Llap
w/o Lhoi-phys
w/o Lrepos
w/o VLM
all
30.4
30.3
31.0
31.3
31.4
Table 3: Ablation results with CLIP score. Higher scores indicate better performance. Our complete method shows the best score.
Method
CLIP ↑
Pene. ↓
Downsample
30.9
7.3 ×10−5
Marching Cubes
26.8
2.3 ×10−5
SuGaR
30.4
3.8 ×10−5
Ours
31.4
2.2 ×10−5
Table 4: Ablation of object mesh reconstruction methods.
w/o phys. opt
w/o VLM
Ours (all)
13
25
61
Table 5: Ablation of physics optimization and VLM refinement using GPT-4o select metric. Values indicate the preference frequency (one sample excluded due to GPT-4o non-response).
Figure 5: VLM refinement results. Left: “A right hand calling a smartphone”. Middle: “A right hand using a hammer”. Right: “A right hand inspecting Paddington Bear”.
Figure 6: User preference study for THOM.
Method
CLIP ↑
T 3 -Align ↑
Contact ratio ↑
Disp. ↓
Baseline
30.4
1.9
0.98
0.25
+ phys. opt
31.3
2.0
0.95
0.20
+ VLM refine (full)
31.4
2.6
0.95
0.20
Table 6: Contribution of physics optimization and VLM-guided translation refinement.
Method
Llap
Lpene
Loc
Lhc
concise mesh
Lrepos
Lcons
VLM refine
CLIP ↑
w/o Llap
×
◯
◯
◯
◯
◯
◯
◯
30.4
w/o Lpene
◯
×
◯
◯
◯
◯
◯
◯
30.4
w/o Loc
◯
◯
×
◯
◯
◯
◯
◯
30.8
w/o Lhc
◯
◯
◯
×
◯
◯
◯
◯
30.9
w/o concise mesh
◯
◯
◯
◯
×
◯
◯
◯
31.0
w/o Lrepos
◯
◯
◯
◯
◯
×
◯
◯
31.0
Table 7: Comprehensive ablation results of our proposed method.
Figure 7: Diverse generation results of our method from various HOI prompts.
Figure 8: Visualization of hand and object contact maps. Input prompt: ”A right hand using a tambourine.”
Technical University of Munich School of Computation, Information and Technology · Tongji University Shanghai Research Institute for Intelligent Autonomous Systems