Re: Interleaved arrays and vertex attribute arrays...

Subject: Re: Interleaved arrays and vertex attribute arrays...

From: Daniel Koch <email@hidden>

Date: Fri, 28 Nov 2008 07:13:00 -0500

Delivered-to: email@hidden

Hi Stephen,

I don't believe that interleaved arrays work that way. If you want to do instancing you are really after something like ARB_instanced_arrays (please file a request for support for that extension!).

Otherwise, something like point sprites (if your quads are small enough) or using geometry shaders to expand out points into quads is are likely your best bets.

Hope this helps,

Daniel

On 27-Nov-08, at 11:27 PM, Stephen Northcott wrote:

I wonder if someone can clarify this for me...

If I am using interleaved arrays to try and reduce vertex buffer sizes for quads.
i.e. One actual coordinate referenced 4 times in the Element array.

Do the vertex attribute arrays run concurrent with the element array, or with each vertex?

In short can I use an attribute array to pass an individual piece of data for each indexed vertex, or (as it appears) are the indexes in the attribute array slaved to each actual vertex definition?

If the answer is the latter, is there any way to do faux instancing like this, and avoid uploading 3 extra sets of redundant and identical vertices for quads?

Cheers,
Stephen.

---

Daniel Koch -+- email@hidden

Graphics Technology Lead -+- TransGaming Inc. -+- www.transgaming.com

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References:
	>Interleaved arrays and vertex attribute arrays... (From: Stephen Northcott <email@hidden>)