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View Full Version : Reading Z-buffer informations during rasterization



flav1
03-27-2002, 06:39 AM
(First I want you to excuse me for my poor english ...)

I'm working on GeForce3 ...
I want to find an opengl function which permit to take the Z-buffer values during the scene rendering ... at the moment, the solution I have found is:
Between two declarations of polygons(part of a surface of an object), I practice a glReadBuffer on the DephtBuffer ... but this solution forces me to declare the polygons of my objects one by one ! (no use of glut or List to create objects ...) what is not interesting, because of the time I loose !
So, on the Opengl rendering method, all the depht values are evaluated and comparated to the buffer's one ... how can we take back an information of this change ??? (That should be a solution ...) ...
An other solution I have tried is to use the FeedBack, but to have a fine description, I need to create clipping planes near of my focus point ... but it use a lot of time to give sub-polygon vertexs ...
Does anybody have an idea ??
Thanks for your feedback !