I want a semi transparent particle that adds to the color behind it. Stack enough on them on top of each other it will be brighter and brighter until it is pure white. It is of course volumetrics I really want.
I have tried this but it only decreases transparency. Not much surprise there. Is it at all possible?
My result with the Add shader. Light isn't added (then it would be white). It is only the transparency that goes away.
My node setup with the Add shader. I have also tried it with reversing the colors of the two shaders I add. Similar result.
Start of a solution
Thanks to Gandalf3, I have begun to solve this with only a shader. This is the shader.
This is a test render. I need more geometry, tweek the alphas and some more, but basicly, it is what I want.
I had to increase bounces in light path settings. This is experimental values but work for now. If not changed, the central part of the flames would be black.