Can you make a bump map using grey scale after you texture paint? I'm working on an apple model and am about to texture it. I plan on using bump maps, reflection maps, etc. My only problem is that it would be much easier for me to texture paint the apple instead of using an image or such. What I was wondering if it's possible to turn the texture painting I do on the apple into a bump map using grey scale, or do I need to use an image directly?
It is possible to directly paint your bump maps and view it real time. 

Its a little hard to see in the GIF but works perfect close up. 



Here is a flat plane (Not subdived). 



This is the render view 



Just make a new image texture and make sure it is set to 50% grey, So when you paint white it bumps up and black bumps down. 




This is what the image texture looked like after painting.