I want to render some soft round particles. Currently I'm rendering white quads with an alpha value calculated as:
float alpha = 1.0f - clamp(length(position), 0.0f, 1.0f);
The blending function looks like:
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
But the particles seem to subtract from each other around the outside (dark halo):
[attachment=24091:example.jpg]