Various tools for creating/editing textures in editor and/or at run time. Primarily designed for OpenGL, I'm working on improving support/stability.

Forum
Documentation

Features
-Baker for projection based PBR painting in editor and at runtime.
-Stamper for UV rectangle based PBR painting in editor and at runtime.
-TerrainStamper for terrain creation using projected textures.
-Import .abr (Photoshop brushes) or .gbr (Gimp brushes) to mask textures.
-Image processing stacks, for editor textures or creating things like normal maps.
-And more.

Baker Features
-Projection based texture painting.
-Fast bake time typically less than .1 ms.
-Normal blending and auto normal rotation.
-Height blending.
-ProceduralMaterial support.
-Text support. (Early)(Through TextMesh Pro.)

TerrainStamper Features
-Stamp textures to height, alpha layers, and detail layers.
-Mass place trees with masking and filtering options.
-Branched path system with smoothing options, for easily creating mountain ranges, city paths, rivers...

Demos are included.

WARNING: Painting wont work as well where meshes share UVs. For instance, the Standard Assets Ethan model uses the same uv for both arms so anything you paint to one will paint to the other.

Tested on Windows developed on Linux.