https://www.allegorithmic.com/products/substance-painter  

Substance Painter is a brand new 3D Painting app with never before seen features and workflow improvements to make the creation of textures for 3D assets easier than ever. It is acknowledged as the most innovative and user-friendly 3D Painter out there.

- Paint full materials, in real-time
Choose your brush, select a material, tweak it if needed and then start painting! Each stroke applies all channels at once and the render is instantaneous, making it the most interactive 3D Painter out there. Paint multiple materials on one mesh, with each map going up to 4K resolution.

- Next-Gen viewport
Preview your painting in a Physically based (PBR) viewport for accurate material feedback. Create beauty shots of your assets using one of the best optical effects technology out there (Yebis 2 by Silicon Studio) adding antialiasing, color correction, DOF, glare, bloom and much more.

- Particle brushes
Throw dirt, fire or even make it rain on your object and watch the realistic weathering effects unfold in real time! Any material can be painted with particle brushes and these can be tweaked to an infinity of variations. Advanced users can also create their own particles using the editor provided by Popcorn FX.

- Use any rendering shader
Import your own custom shaders and create your own channels to paint on. You can also use pre-built shaders such as the standard PBR (Physically-Based) or even one of the non-photorealistic rendering shaders we provide, like a simple toon shader.