论文标题
Epigraf:重新思考3D GAN的培训
EpiGRAF: Rethinking training of 3D GANs
论文作者
论文摘要
生成建模的最新趋势是从2D图像收集中构建3D感知发电机。为了诱发3D偏见,此类模型通常依赖于体积渲染,这在高分辨率上使用昂贵。在过去的几个月中,通过训练单独的2D解码器来对纯度3D发电机产生的低分辨率图像(或特征张量)进行示例来解决这个扩展问题。但是该解决方案是有代价的:它不仅打破了多视图的一致性(即相机移动时的形状和纹理变化),而且还以低忠诚度学习了几何形状。在这项工作中,我们表明,可以通过遵循完全不同的途径,仅训练模型贴片,可以获得具有SOTA图像质量的高分辨率3D发电机。我们通过两种方式重新审视和改进此优化方案。首先,我们设计了一个位置和规模感知的歧视者,以处理不同比例和空间位置的贴片。其次,我们基于退火的beta分布来修改斑块采样策略,以稳定训练并加速收敛。所得的模型名为Epigraf,是一个高效,高分辨率的纯3D发电机,我们在四个数据集(在这项工作中引入两个)上对其进行了测试,价格为$ 256^2 $和$ 512^2 $分辨率。它获得了最先进的图像质量,高保真的几何形状,并比基于UpSampler的同行训练$ {\ of tims $ $ a。项目网站:https://universome.github.io/epigraf。
A very recent trend in generative modeling is building 3D-aware generators from 2D image collections. To induce the 3D bias, such models typically rely on volumetric rendering, which is expensive to employ at high resolutions. During the past months, there appeared more than 10 works that address this scaling issue by training a separate 2D decoder to upsample a low-resolution image (or a feature tensor) produced from a pure 3D generator. But this solution comes at a cost: not only does it break multi-view consistency (i.e. shape and texture change when the camera moves), but it also learns the geometry in a low fidelity. In this work, we show that it is possible to obtain a high-resolution 3D generator with SotA image quality by following a completely different route of simply training the model patch-wise. We revisit and improve this optimization scheme in two ways. First, we design a location- and scale-aware discriminator to work on patches of different proportions and spatial positions. Second, we modify the patch sampling strategy based on an annealed beta distribution to stabilize training and accelerate the convergence. The resulted model, named EpiGRAF, is an efficient, high-resolution, pure 3D generator, and we test it on four datasets (two introduced in this work) at $256^2$ and $512^2$ resolutions. It obtains state-of-the-art image quality, high-fidelity geometry and trains ${\approx} 2.5 \times$ faster than the upsampler-based counterparts. Project website: https://universome.github.io/epigraf.