S3's Delta Chrome

[Inspirer]

Did anybody understand the "Advanced Deffered Rendering with a two pass rendering scheme" feature ?

over here

please don't comment on s3 in general or compare their past products to ATI's, Nvidia's or 3dfx's
this is a question specifically about a certain technological concept.

what do they mean by "analizing depth complexity" and by repeatedly referring to the Z Buffer in Plural ?

is it possible that the card is dynamically allocating Z storage space in order to store multiple Z values for each pixel?

 

[Inspirer]

what I think is going on, is that in the first pass they only calculate Z values for all the pixels in the scene.
instead of storing the z values, they use them to build for every pixel an array of 1bit values that determine if the pixel is drawn(1) or discarded(0).
the order of the values in the array is the same order the app is sending the commands.
This way, effectively you don't need a Z buffer. you use a regular single Z buffer in the first pass and use it to build the bit arrays.
but when you have the arrays built (together they act as multiple Z buffers) you don't need your original Z buffer anymore, you can ditch it.

in the second pass, when the card has to decide whether or not to render a pixel, it reads the array's realevant block
(which is the amount of times the current pixel was accessed in the current frame).
if the block equals 0, the pixel is skipped.
if the block equals 1, the pixel is proccessed and blended with the currently stored pixel.

things I saw on s3's site that made me come up with this :
* they said that in the first pass, no values are stored in the frame buffer.
* they used the phrase "depth complexity" (the length of the bit array equals the scene's maximum depth complexity)

 

[Idoxash]

I do not know to much of this new gfx chip or even the new one from trident... But I would love too see any small gfx maker get into the game.