Download free texture de-lighting tool Agisoft De-Lighter
Agisoft has released Agisoft De-Lighter, a free standalone tool for removing baked-in lighting from the texture maps of 3D models generated through photogrammetry.
The new software is based on the built-in de-lighting functionality in Metashape, Agisoft’s popular image-based modelling software, formerly known as PhotoScan.
Remove baked shadows and ambient occlusion from photogrammetric texture maps
Agisoft De-Lighter rectifies a common issue in photogrammetry: that real-world lighting information becomes baked into texture maps, resulting in issues when the 3D model is re-lit inside DCC software.
According to Agisoft, the software is intended to remove cast shadows and ambient occlusion from colour textures, leaving them ready for re-lighting.
It’s designed for use with textured 3D models: unlike online service Lightbrush Cloud, which we wrote about last month, you can’t use it with the source photos themselves.
However, its core algorithm is optimised for 8-bit JPEG textures, meaning that it doesn’t require the RAW data or high-bit-depth images that Lightbrush Cloud prefers.
Sketch in light and shadow areas manually to tune the de-lighting process
Unlike some other tools for de-lighting photogrammetric textures, like Unity Technologies’ free Unity add-on, De-Lighter doesn’t require additional texture maps like ambient occlusion or bent normals.
That means that the initial workflow requires rather more manual input, with the user sketching in the viewport to indicate light and shadow areas, as shown by the blue and yellow strokes in the image above.
Output can then be fine-tuned by adjusting global parameters, or using user-generated ‘shadow scale maps’ to exclude parts of a texture from the calculation, or to identify matching materials.
Once processed, the model and its de-lit textures can be exported in “various formats” or uploaded to online portfolio service Sketchfab. You can see the workflow in more detail via the link below.
Availability and system requirements
Agisoft De-Lighter 1.5.4 is available free for Windows, Linux and macOS.
At the time of posting, the blog post linked below seems to be the only written documentation available online, but Agisoft has just opened a new section on its forum devoted to the software.
Read more about Agisoft De-Lighter in Agisoft’s tutorial blog post