Have a look at the snippet code [url]WIP - Fast offscreen soft particles], I didn’t success to get soft particles but it’s working with a simple z-test.
You need one dedicated buffer + camera for the particles and hide them from the main rendering camera.
You need one dedicate buffer & camera for your objects/scene and hide it from the particles camera.
You must have 4 textures :
- 1 texture for scene depth,
- 1 texture for scene colors,
- 1 texture for particles depth (reduced size buffer),
- 1 texture for particles colors (reduced size or not).
postimage.org/image/2l1aghlno/
Then you combine them in a compositing shader.
It may be overkill but I didn’t find simpler way to do it in Panda.
What is the cause of fps drop is the overdraw caused by the alpha of the particles textures in front of each other, I think you’ll get this in all engines.