Recent text-to-image (T2I) models have benefited from large-scale and high-quality data, demonstrating impressive performance. However, these T2I models still struggle to produce images that are aesthetically pleasing, geometrically accurate, faithful to text, and of good low-level quality. We present VersaT2I, a versatile training framework that can boost the performance with multiple rewards of any T2I model. We decompose the quality of the image into several aspects such as aesthetics, text-image alignment, geometry, low-level quality, etc. Then, for every quality aspect, we select high-quality images in this aspect generated by the model as the training set to finetune the T2I model using the Low-Rank Adaptation (LoRA). Furthermore, we introduce a gating function to combine multiple quality aspects, which can avoid conflicts between different quality aspects. Our method is easy to extend and does not require any manual annotation, reinforcement learning, or model architecture changes. Extensive experiments demonstrate that VersaT2I outperforms the baseline methods across various quality criteria.
City layout generation has recently gained significant attention. The goal of this task is to automatically generate the layout of a city scene, including elements such as roads, buildings, vegetation, as well as other urban infrastructures. Previous methods using VAEs or GANs for 3D city layout generation offer limited diversity and constrained interactivity, only allowing users to selectively regenerate parts of the layout, which greatly limits customization. In this paper, we propose CityGen, a novel end-to-end framework for infinite, diverse and controllable 3D city layout generation.First, we propose an outpainting pipeline to extend the local layout to an infinite city layout. Then, we utilize a multi-scale diffusion model to generate diverse and controllable local semantic layout patches. The extensive experiments show that CityGen achieves state-of-the-art (SOTA) performance under FID and KID in generating an infinite and controllable 3D city layout. CityGen demonstrates promising applicability in fields like smart cities, urban planning, and digital simulation.