Free tools for transforming textures on 3D models include Blender (for UV mapping and direct painting), GIMP, and Krita (for editing 2D texture files).
- Blender handles UV mapping (aligning textures to 3D surfaces) and direct texture painting, so you can edit in the model’s context. - GIMP and Krita are 2D editors for modifying texture files (like PNG/JPG) before applying them to 3D objects.
For beginners, start with Blender’s Texture Paint mode—it lets you see changes in real time on the model, no need to switch tools.