Implementation - transparency in OpenGL

Transparency is not straightforward using projection/rasterization rendering.

\(\Rightarrow\) Possibility to blend color for each pixel using \(\alpha\) channel (rgba)

glEnable(GL_BLEND); 
glBlendFunc (GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
 ... Draw Calls ... 
glDisable(GL_BLEND);

- - Various blending are possible for multiple effects (see glBlendFunc)
- - For transparency: (GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA)
- - \(\Rightarrow\) newColor = \(\alpha\) currentColor + \((1-\alpha)\) previousColor

Important note: