When I using the Additive(glBlendFunc(GL_ONE, GL_ONE) ) to do the blending for the particle system, if where have a background it will looks perfect, but when I try without background, it will get the black color.
The result is when not background(RGBA(0,0,0,0)), the Additive will add the black color together, for example:
RGBA(0,0,0,1) + background(RGBA(0,0,0,0)) = RGBA(0,0,0,1);
so that is why I get the black color.
How to make it happen:
- Run in android without background, but have wallpaper.
- Using Fbo and Fbo clear color is RGBA(0,0,0,0), and with Translucent, then draw a bitmap to the Fbo with Additive.
Question: How to solve this problem, make the bitmap won't have black color, or how to avoid that when without background.