multi pass shaders ?

[divide]

talking about "multi pass".. is there really a way to develop true multi pass fragment shaders ? Since it is impossible to read back from the framebuffer, or transmit values from one fragment pass to the next fragment pass, how can we talk about multi pass beyond the simple color blend provided by opengl core ?

I heard that ashli could decompose shaders in different pass. how is this possible ? how can fragments shaders receives values from the previous pass ? (and avoiding pbuffer, wich can be really slow if you have to change the context hundred times for a single image).

[jeickmann]

Hi,

as far as I know, render-to-texture (currently using pbuffers) is your only option. Hopefully, the new RTT-Extension will be out soon.

Jan

[Humus]

Ashli uses render targets to pass data along to the next pass.

[divide]

"the new RTT-Extension": Render To Target ?

"Ashli uses render targets": what do you mean ? PBuffer/Render to texture ? Or Render To Target extension ? In the last case, isn't this a non yet implemented feature ?