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Index › Programming Questions & Help › OpenGL and 3D Libraries › How can I do subtractive blending

nardove Full Member Offline Posts: 189 UK

How can I do subtractive blending? Mar 15th, 2010, 2:12am   Hi, I want to know how to do subtractive blending, from the very popular flight404 mini tutorial, we know that Code: gl.glBlendFunc(GL.GL_SRC_ALPHA, GL.GL_ONE); Is additive blending, so overlapping pixels will add together and as result you get a bright white colour. So how can I do subtractive? I want the overlapping pixels to go black Any help will be much appreciated rS

koogy God Member Offline Posts: 788	Re: How can I do subtractive blending? Reply #1 - Mar 15th, 2010, 5:25am   http://zanir.wz.cz/?p=60&lang=en and click on the picture for a big version

koogy God Member Offline Posts: 788	Re: How can I do subtractive blending? Reply #2 - Mar 15th, 2010, 5:29am   actually, this might be more useful http://www.opengl.org/sdk/docs/man/xhtml/glBlendEquation.xml which has a GL_FUNC_SUBTRACT value.

Krux YaBB Newbies Offline Posts: 17	Re: How can I do subtractive blending? Reply #3 - Mar 18th, 2010, 9:28am   try it with Code: gl.glBlendFunc(GL.GL_MINUS_SRC_ALPHA, GL.GL_ONE);