Ooh-videogames
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Is bump-mapping, all filter techniques, lighting free on the Xbox and GC or is there a performance hit.
Ialways believed anything done in hardware is free.
Ialways believed anything done in hardware is free.
Console hardware features whats free and whats not
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megadrive0088
Regular
costly:
lighting
texturing
bump-mapping
tri and aniso filtering
anti-aliasing
virtually free(?)
bilinear filtering
mip-mapping
lighting
texturing
bump-mapping
tri and aniso filtering
anti-aliasing
virtually free(?)
bilinear filtering
mip-mapping
G
Guest
Guest
Nothing is free.
Most of us know Kristof's saying, but hardware can be designed in a way that certain features can be used without performance cost anymore (e.g. by adding dedicated hardware that only boosts a certain feature) and could thus be considered free (as long as you don't talk about the costs of hardware development and manufacturing). 
Take Xbox for example, if its GPU's PC counterparts are anything to go by, then trilinear filtering should be virtually free on Xbox - at least in the sense that reverting to the next best filtering, bilinear, doesn't give you a performance boost. Apart from that I think megadrive0088's list is correct, FSAA, Aniso, Bumpmapping, etc. certainly don't come for "free" on any of today's console hardware.
Its always a matter of using features in a well balanced way so that no single feature becomes the performance bottleneck for your game/engine...
Take Xbox for example, if its GPU's PC counterparts are anything to go by, then trilinear filtering should be virtually free on Xbox - at least in the sense that reverting to the next best filtering, bilinear, doesn't give you a performance boost. Apart from that I think megadrive0088's list is correct, FSAA, Aniso, Bumpmapping, etc. certainly don't come for "free" on any of today's console hardware.
Its always a matter of using features in a well balanced way so that no single feature becomes the performance bottleneck for your game/engine...
Pretty much as Kristoff used to say "Nothing is free in 3D".
This is particularly true of none hardwired features and as hardware becomes more programmable this encompasses a wider variety of features.
Doing a Dot Product for bump mapping on NV2A is no more expensive than any other combiner operation. However bumpmapping still requires an extra texture and the VS needs to do extra work.
If you think about this for a second it's a pretty dumb question, lets say that you design a piece of hardware that only outputs one pixel every 1000 or so clock cycles. Anything you could do in that 1000 or so clock cycles would be take exactly the same amount of time and is therefore "free". The fact is it's clearly not, you've compromised the performance of simpler verts or pixels, everything is a tradeoff and there is no such thing as free.
This is particularly true of none hardwired features and as hardware becomes more programmable this encompasses a wider variety of features.
Doing a Dot Product for bump mapping on NV2A is no more expensive than any other combiner operation. However bumpmapping still requires an extra texture and the VS needs to do extra work.
If you think about this for a second it's a pretty dumb question, lets say that you design a piece of hardware that only outputs one pixel every 1000 or so clock cycles. Anything you could do in that 1000 or so clock cycles would be take exactly the same amount of time and is therefore "free". The fact is it's clearly not, you've compromised the performance of simpler verts or pixels, everything is a tradeoff and there is no such thing as free.
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