A technique for painting directly on 3D surfaces is proposed to synthesize complex textures in this paper. Different from the conventional 2D paint system, the color painted by each stroke is applied as surface attributes to set up various textures and shading effects on 3D surfaces in real time. The approach allows users to continuously blend the texture on adjacent surface and blend multi-layer textures on the same surface.Results demonstrate that the method can be employed to create very complex textures.