Z-Buffer FAQ?

Discussion in 'Architecture and Products' started by Jimmers, Jul 6, 2004.

  1. Quitch

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    So, what is the downside of all this additional precision? Larger memory hit? Takes more bandwidth?
     
  2. Cryect

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    Basically, and really you definately don't want to be using 16 bit Z-Precision anymore (well unless you are messing around with something that is really low poly count where as well the polys aren't close together).
     
  3. Quitch

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    Okay, but say then 24bit compared to 24bit 8bit. What's the up and down sides to going with the additional 8bit stencil over plain old 24bit?
     
  4. Cryect

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    Heh as far as I know just that you get a stencil buffer. Either way you have to read you data 32 bits at a time. It could be possible those 8 bits really get used in some other way to help performance but I don't know. Also not sure on this but it might be easier to do Z-Buffer compression when you don't have stencil bits since thats 8 less bits you have to worry about trying to compress.
     
  5. KimB

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    The stencil buffer is a programmer's tool. It's not related directly to turning on any performance or effects.
     
  6. Mendel

    Mendel Mr. Upgrade
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    So even if I select a mode in radlinker, where there is not this 8 bit stencil listed, I will still get stencil shadows when game requests such a thing?
     
  7. Simon F

    Simon F Tea maker
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    I think it's likely that you'll find that, in the above cases, if you haven't enabled the stencil, the 24 bit Z data will still be put into 32bit units and the remaining 8 bits ignored. Its the same with 24bit colour.
     
  8. KimB

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    I don't think the game would be able to run its stencil algorithm if the stencil buffer is disabled, no.
     
  9. Quitch

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    From what I can gather, there seems little point in selecting anything other than 16,24,8bit stencil?
     
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