True Reality (TR) is an open source LGPL Game and Simulation Engine written entirely in Standard C++ and OpenGL. It runs on all Windows platforms and GNU/Linux. OpenSceneGraph is used as its graphics engine, along with many other open source projects for support of various features.
Have shaders use the PBR model.
Some links on the topic:
https://www.marmoset.co/toolbag/learn/pbr-theory https://docs.unrealengine.com/latest/INT/Engine/Rendering/Materials/PhysicallyBased/index.html https://jmonkeyengine.org/299803/physically-based-rendering-part-one/
-IR material Info -Heat