Multi-subject personalized image generation aims to synthesize customized images containing multiple specified subjects without requiring test-time optimization. However, achieving fine-grained independent control over multiple subjects remains challenging due to difficulties in preserving subject fidelity and preventing cross-subject attribute leakage. We present FocusDPO, a framework that adaptively identifies focus regions based on dynamic semantic correspondence and supervision image complexity. During training, our method progressively adjusts these focal areas across noise timesteps, implementing a weighted strategy that rewards information-rich patches while penalizing regions with low prediction confidence. The framework dynamically adjusts focus allocation during the DPO process according to the semantic complexity of reference images and establishes robust correspondence mappings between generated and reference subjects. Extensive experiments demonstrate that our method substantially enhances the performance of existing pre-trained personalized generation models, achieving state-of-the-art results on both single-subject and multi-subject personalized image synthesis benchmarks. Our method effectively mitigates attribute leakage while preserving superior subject fidelity across diverse generation scenarios, advancing the frontier of controllable multi-subject image synthesis.

We propose a neural reflectance model (NeuBRDF) that offers highly versatile material representation, yet with light memory and neural computation consumption towards achieving real-time rendering. The results depicted in Fig. 1, rendered at full HD resolution on a contemporary desktop machine, demonstrate that our system achieves real-time performance with a wide variety of appearances, which is approached by the following two designs. Firstly, recognizing that the bidirectional reflectance is distributed in a sparse high-dimensional space, we propose to project the BRDF into two low-dimensional components, i.e. two hemisphere feature-grids for incoming and outgoing directions, respectively. Secondly, we distribute learnable neural reflectance primitives on our highly-tailored spherical surface grid. These primitives offer informative features for each hemisphere component and reduce the complexity of the feature learning network, leading to fast evaluation. These primitives are centrally stored in a codebook and can be shared across multiple grids and even across materials, based on low-cost indices stored in material-specific spher-ical surface grids. Our NeuBRDF, agnostic to the material, provides a unified framework for representing a variety of materials consistently. Comprehensive experimental results on measured BRDF compression, Monte Carlo simulated BRDF acceleration, and extension to spatially varying effects demonstrate the superior quality and generalizability achieved by the proposed scheme.

Micro-mesh (μ-mesh.) is a new graphics primitive for compact representation of extreme geometry, consisting of a low-polygon base mesh enriched by per micro-vertex displacement. A new generation of GPUs supports this structure with hardware evolution on μ-mesh ray tracing, achieving real-time rendering in pixel level geometric details. In this article, we present a differentiable framework to convert standard meshes into this efficient format, offering a holistic scheme in contrast to the previous stage-based methods. In our construction context, a μ-mesh is defined where each base triangle is a parametric primitive, which is then reparameterized with Laplacian operators for efficient geometry optimization. Our framework offers numerous advantages for high-quality μ-mesh production: (i) end-to-end geometry optimization and displacement baking; (ii) enabling the differentiation of renderings with respect to μ-mesh for faithful reprojectability; (iii) high scalability for integrating useful features for μ-mesh production and rendering, such as minimizing shell volume, maintaining the isotropy of the base mesh, and visual-guided adaptive level of detail. Extensive experiments on μ-mesh construction for a large set of high-resolution meshes demonstrate the superior quality achieved by the proposed scheme.

We develop a simple yet surprisingly effective implicit representing scheme called Multiplicative Fourier Level of Detail (MFLOD) motivated by the recent success of multiplicative filter network. Built on multi-resolution feature grid/volume (e.g., the sparse voxel octree), each level's feature is first modulated by a sinusoidal function and then element-wisely multiplied by a linear transformation of previous layer's representation in a layer-to-layer recursive manner, yielding the scale-aggregated encodings for a subsequent simple linear forward to get final output. In contrast to previous hybrid representations relying on interleaved multilevel fusion and nonlinear activation-based decoding, MFLOD could be elegantly characterized as a linear combination of sine basis functions with varying amplitude, frequency, and phase upon the learned multilevel features, thus offering great feasibility in Fourier analysis. Comprehensive experimental results on implicit neural representation learning tasks including image fitting, 3D shape representation, and neural radiance fields well demonstrate the superior quality and generalizability achieved by the proposed MFLOD scheme.