I'm writing this speed tool that paints 3d models, but id like to have a more "complete" brush package to come with it. Id like to include dodge and burn in its toolset, but have no idea how to actually code it.
Simple google search didnt produce any results... can anyone help?
The brushes using these blend modes in photoshop is the same as layer blend modes, but using the brush colour instead. They can be quite destructive so you might be better implementing them as layers. Search google for:
equation dodge burn
You should find plenty of info, the layer blend modes have been documented many times.
Hi rouncer,
Here's a page with code for all of Photoshop's blend modes. http://inlandstudios.com/en/?p=851 It's written using C macros so it looks a bit weird, but the maths you want is all there, including dodge and burn. I used this info a while ago when I wanted to create a procedural animation using the overlay blend mode.
If you search for Photoshop blend modes, you'll find a lot more info out there.
(EDIT) Heres another good page on the blend modes: http://photoblogstop.com/photoshop/photoshop-blend-modes-explained
