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Laarz

Hardware T&L

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Hi, I read a review of the new GeForce 2 GTS, and they said that games like Q3A etc. would benefit from the hardware T&L (Yeah, I know, GeForce has HW T&L, so it''s nothing new to GF2GTS), but does it really? Doesn''t Q3A do transformations and lighting in the engine, rather than using OpenGL functions (Quake 1 and 2 does it this way, at least)? What is the point in releasing graphics chips with HW T&L if no games uses it? I know, there will probably be games supporting it in the near future, but considering the advantages of coding your own T&L functions (such as more control in clipping etc.), how many??

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I think DirectX 7 supports hardware transform and lighting. I don''t know how Q3A does it''s lighting - the 8 OpenGL light sources wouldn''t be enough I think.

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GA

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If Q3A lets the card do the some of the transforms, such as the projection matrix, then yes, it should perform better.

As far as nobody using it, well, a lot of games are using it already. More games will use it in the future. As with any new technology, you have to give the industry time to catch up.

Tim

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Quake 3 does take advantage of TnL, as do a lot of the games released this year. Remember, commerical game developers have access to DirectX 7.0 spec (which featured TnL) / most recent OpenGl extensions, and Geforce cards ages before anyone else!

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Well, I''m well aware of all the information from you guys, but I''m still a bit confused, because from what I have heard Q3A (and lots of other FPS games, such as UT) does all of it''s transformation in code, rather than using API functions. (Or is it so that Mr. Carmack has been rethinking, and decided to use OpenGL transformations? )

The reason for this is that it''s possible to perform a lot more culling as fast as possible in the pipeline if you''re coding your own transformation routines ("BSP node/View frustum" culling etc..), which results in much higher framerates, and this is impossible to do if you''re using API functions.

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Well the geforce cards DO have only 8 light hw lights. DX or OpenGL just calculates the rest on the CPU. Quake 3 does not use vertex lighting. Quake3 CAN use vertex lighting, but we all know vertex lighting sucks and that is just a bad option.

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Quake3 uses OpenGL for transforms, and uses multitexturing with lightmaps, gloss maps, etc. for the lighting. The new Geforce 2 cards support more than 8 active lights at one time. Per-vertex lighting does not "suck", it just doesn''t look as nice at current polygonal resolutions. As far as asking why TnL was introduced if nobody''s using it, if someone doesn''t introduce new features, then where does the innovation come from? It just takes the games some time to catch up.

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Hi

I do not know how Q3A is transforming their 3D Data, but there aren''t just Levels, which are done with BSP-Trees, there are also Charakters running around which are transformed "normaly" (with standard API Functions). So if the CPU transforms the Levels and the GPU transforms the Player''s, than you can get an speed increase.
The thing with those Hardware Lights, is that it means 8 Lights per Vertex. That means, if have to Objects, and you wan''t to render them, you can set 8 Lights to enlight the first Object, then send the Data tothe Card and it calculates all the Lighting and so on. then change the Lights Position, to enlight the second Object, and draw that. Voila you have 16 Hardware Supported Lights, and normally you don''t need that much Lights per Object.

And with the new per Pixel Lighting, you get the same, mostly better Results, than with Lightmaps, and that fully dynamic, at no extra cost.
But as every new Feature, it could take some Month so that many Games support that.

Lars

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