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iliak

Point Sprite

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Hello in the current featured article, it says : "Point sprites were introduced in DirectX 8.0. They offer a nice advantage over the normal method of rendering particles. Normally you would create a rectangle using four view-aligned vertices set to the appropriate texture coordinates. With point sprites you can simply use one vertex for every particle! Therefore they require less bandwidth, so you can render more particles using point sprites instead of using the old method, and you don''t have to manually adjust the vertices to be aligned with the view vector." Is it possible to do the same in OpenGL (send one vertex for a particle) ? - Iliak -

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Yes you can. Look for the GL_ARB_point_sprite extension. It''s supported on GeForce2 and up (with the latest detonator drivers at least). I don''t know what ATI cards support it though. If anyone could tell me i''d be might pleased

Sander Maréchal
[Lone Wolves Game Development][RoboBlast][Articles][GD Emporium][Webdesign][E-mail]

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Ok, thx for the reponses.

Anyway, i''ll check if the extension is supported or not in my code.

What i want to do is to make a particle engine, so does any one have a good source or tutorial ?

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In that case, I assume that not all ATI cards support point sprites in DX8 and up (old cards like the Rage128 and stuff).

Could you tell me the oldest ATI card that supports DX8+ point sprites? I''m guessing that *when* ARB_point_sprites are added, these will be implemented for the same cards.

Sander Maréchal
[Lone Wolves Game Development][RoboBlast][Articles][GD Emporium][Webdesign][E-mail]

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AFAIK, the Radeon 8500 and better support point sprites in hardware.

EDIT: Previous ATI cards were conceived before the DX8 specs arrived, which is when point sprites appeared.

[edited by - Ostsol on October 7, 2003 8:35:08 PM]

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Hmmm.... Just looked at Nvidia''s site. My GeForce2 MX comes from the early DirectX 7.0 era. It still does point sprites though. Any chance that pre 8500 raedons also support point sprites? Like the Raedon 7200?

The reason i''m asking is because I''d like to convert my particle engine to point sprites, but I don''t want to cut out the older cards too much. GeForce2 minimum is okay for Nvidia cards, but a lot of people are owning older ATI cards as well. If it really is Raedon 8500 minimum then I''ll loose too much potential users if I go for pure point_sprite based systems.

Sander Maréchal
[Lone Wolves Game Development][RoboBlast][Articles][GD Emporium][Webdesign][E-mail]

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*shrugs* If they do, it''s probably in software. . .

On ATI''s site there''s a PDF with a list of extensions and the Radeons that support those extensions. There''s an experimental extension called ATIX_point_sprite and it is listed as only being supported by the Radeon 8500 and better.

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