BRL-CAD is a powerful cross-platform constructive solid geometry solid modeling system that includes an interactive geometry editor, ray-tracing for rendering & geometric analyses, network distributed framebuffer support, image & signal-processing tools.
Importer library to import assets from different common 3D file formats such as Collada, Blend, Obj, X, 3DS, LWO, MD5, MD2, MD3, MDL, MS3D and a lot of other formats. The data is stored in an own in-memory data-format, which can be easily processed.
www.open3mod.com/ is a 3D model viewer and exporter based on Assimp that is also Open Source.
StereoWS developed by UCL-MSSL within the ProVisG project
...In addition, a part of software (called StView
ver.1.0) was ported to a web-based GIS system (e.g., ProGIS) and ProVIP as a solution for
stereo visualisation.
Apart from the stereo visualisation, some useful stereo tools (e.g., stereo matcher or stereo
imageprocessing tools) have been extracted from UCL’s previous development for HRSC
data processing, and modified for close-range stereo imagery.