Pixels2Peaks: Converting Terrain Images to Heightmaps

A common process in authoring digital scenes for games, films, and virtual environments is for artists to construct 3D geometry that matches a 2D perspective reference image. In the case of the bare-earth terrain, this is typically a manual process since, unlike for trees and buildings, few inverse reconstruction methods currently exist. To address this, we introduce a method for automatically inferring a detailed, consistent, and complete terrain heightmap from a single photographic image. Our initial phase involves extracting camera parameters and a 3D pointmap from the input image, which is then transformed into a heightmap. However, this only recovers the unoccluded portions of the terrain visible from the perspective of the image. The next phase thus entails the generation of plausible occluded regions using a diffusion model trained on terrain elevation data. The entire process is guided by three consistency principles: geomorphological consistency (the features of the occluded terrain resemble the visible portions), hydrological consistency (the river network is uninterrupted and flows reliably), and view consistency (the shape of the rendered terrain accurately matches the input image). We demonstrate that our method obeys these principles, reliably generates terrains across various scales, and integrates with scene authoring workflows.