Blender - Blender is the open source, cross platform suite of tools for 3D creation.

Union Bytes Painter - 2D sprite and low res texturing tool for editing with color, normal, height, roughness, and metallic maps.

Sculptris - Sculptris: Enter a world of digital art without barriers.

Zero Brush - blendersensei.com/zero-brush Texture painting, sculpting, and baking addon for Blender.

Sketchfab - Sketchfab is an industrial design software tool is useful for ideation and for beginners in the industrial design field.

ZBrush - ZBrush is a digital sculpting and painting software solution.