PI3D: Efficient Text-to-3D Generation with Pseudo-Image Diffusion

Diffusion models trained on large-scale text-image datasets have demonstrated a strong capability of con-trollable high-quality image generation from arbitrary text prompts. However, the generation quality and general-ization ability of 3D diffusion models is hindered by the scarcity of high-quality and large-scale 3D datasets. In this paper, we present PI3D, a framework that fully lever-ages the pre-trained text-to-image diffusion models' abil-ity to generate high-quality 3D shapes from text prompts in minutes. The core idea is to connect the 2D and 3D domains by representing a 3D shape as a set of Pseudo RGB Images. We fine-tune an existing text-to-image dif-fusion model to produce such pseudo-images using a small number of text-3D pairs. Surprisingly, we find that it can al-ready generate meaningful and consistent 3D shapes given complex text descriptions. We further take the generated shapes as the starting point for a lightweight iterative re-finement using score distillation sampling to achieve high-quality generation under a low budget. PI3D generates a single 3D shape from text in only 3 minutes and the quality is validated to outperform existing 3D generative models by a large margin.