Trajectory distillation based on consistency models (CMs) provides an effective framework for accelerating diffusion models by reducing inference steps. However, we find that existing CMs degrade style similarity and compromise aesthetic quality in stylization tasks-especially when handling image-to-image or video-to-video transformations that start denoising from partially noised inputs. The core limitation stems from existing methods enforcing initial-step alignment between the probability flow ODE (PF-ODE) trajectories of student models and their imperfect teacher models. This partial alignment strategy inevitably fails to guarantee full trajectory consistency, thereby compromising the overall generation quality. To address this issue, we propose Single Trajectory Distillation (STD), a training framework initiated from partial noise states. To counteract the additional time overhead introduced by STD, we design a trajectory bank that pre-stores intermediate states of the teacher model's PF-ODE trajectories, effectively offsetting the computational cost during student model training. This mechanism ensures STD maintains equivalent training efficiency compared to conventional consistency models. Furthermore, we incorporate an asymmetric adversarial loss to explicitly enhance style consistency and perceptual quality in generated outputs. Extensive experiments on image and video stylization demonstrate that our method surpasses existing acceleration models in terms of style similarity and aesthetic evaluations. Our code and results are available on the project page: https://single-trajectory-distillation.github.io/.

Diffusion models have demonstrated remarkable capabilities in generating high-quality images. Recent advancements in Layout-to-Image (L2I) generation have leveraged positional conditions and textual descriptions to facilitate precise and controllable image synthesis. Despite overall progress, current L2I methods still exhibit suboptimal performance. Therefore, we propose InstanceAssemble, a novel architecture that incorporates layout conditions via instance-assembling attention, enabling position control with bounding boxes (bbox) and multimodal content control including texts and additional visual content. Our method achieves flexible adaption to existing DiT-based T2I models through light-weighted LoRA modules. Additionally, we propose a Layout-to-Image benchmark, Denselayout, a comprehensive benchmark for layout-to-image generation, containing 5k images with 90k instances in total. We further introduce Layout Grounding Score (LGS), an interpretable evaluation metric to more precisely assess the accuracy of L2I generation. Experiments demonstrate that our InstanceAssemble method achieves state-of-the-art performance under complex layout conditions, while exhibiting strong compatibility with diverse style LoRA modules. The code and pretrained models are publicly available at \url{https://github.com/FireRedTeam/InstanceAssemble}.