Help with texture paint in game engine?

So I have a simple building but I want to add some cracks as if it was old. I am not sure if it matters but I am using GLSL and when I go in texture paint mode, I choose my texture I click to paint but nothing shows up? How do I fix this?

If you want to add cracks, you need do more work to improve the output effect!

what??? I don’t see what you are saying?

Make a new UV-image, if you don’t have one, and ensure that it’s applied to the mesh (in edit-mode, UV-Unwrap (may not be necessary), and select the image). After that, you should be able to paint on the image with Texture Paint mode. The larger the image you used, the longer it will take to paint on it.

oh ok thanks solarlune

No problem.