The present disclosure relates to systems, methods, and non-transitory computer-readable media that generates object shadows for digital images utilizing corresponding geometry-aware buffer channels. For instance, in one or more embodiments, the disclosed systems generate, utilizing a height prediction neural network, an object height map for a digital object portrayed in a digital image and a background height map for a background portrayed in the digital image. The disclosed systems also generate, from the digital image, a plurality of geometry-aware buffer channels using the object height map and the background height map. Further, the disclosed systems modify the digital image to include a soft object shadow for the digital object using the plurality of geometry-aware buffer channels.