Abstract: Gradient-domain rendering methods can render higher-quality images at the same time cost compared with traditional ray tracing rendering methods, and, combined with the neural network, achieve better rendering quality than conventional screened Poisson reconstruction. However, it is still challenging for these methods to keep detailed information, especially in areas with complex indirect illumination and shadows. We propose an unsupervised reconstruction method that separates the direct rendering from the indirect, and feeds them into our unsupervised network with some corresponding auxiliary channels as two separated tasks. In addition, we introduce attention modules into our network which can further improve details. We finally combine the results of the direct and indirect illumination tasks to form the rendering results. Experiments show that our method significantly improves image quality details, especially in scenes with complex conditions.