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Raeldor

Indexed Primitive Drawing... Just Simple?

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Ignoring shaders, am I right in saying that indexed primitive drawing in DirectX is a pretty simple implementation? I mean, it seems all the data is attached to the vertices, whereas some of it (such as the UV's) would be better attached to the indexed faces. Looking at the API, it seems that the indexing is just a basic list of vertex indexes for each triangle. Is this a fair statement or am I missing something? Thanks Ray

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Quote:
it seems all the data is attached to the vertices


That's the way, gfx card handle the data. Even in OpenGL uv's are
attached to the vertices. If you need more than one uv per vertex
you will have to duplicate them.

Quote:
it seems that the indexing is just a basic list of vertex indexes for each triangle


indeed. How did you come to that conclusion? ;)
however, depending on the primitive you're drawing (tri-list, tri-strip, tri-fan), the indices have to be in a specific order.

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Quote:
Original post by Madhed
Quote:
it seems all the data is attached to the vertices


That's the way, gfx card handle the data. Even in OpenGL uv's are
attached to the vertices. If you need more than one uv per vertex
you will have to duplicate them.

Quote:
it seems that the indexing is just a basic list of vertex indexes for each triangle


indeed. How did you come to that conclusion? ;)
however, depending on the primitive you're drawing (tri-list, tri-strip, tri-fan), the indices have to be in a specific order.


Haha, ok I asked for that last one, lol. By specific order, are you talking about the winding order for backface culling? Or that tri-strip needs less indexes (ie, not 3 per face like tri-list)?

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