support for models without indices ?

[fabrobinet]

We agreed to start conservative by doing so, though we are aware it can be not convenient for points. Keep track of this here for now.

[fabrobinet]

Patrick initial question was: "Do all COLLADA models have indices or do we need to adjust the statement about drawArrays above? Or make changes to the converter?" . I would say YES.

[fabrobinet]

I mean YES COLLADA models have indices, but we still need to decide if we adjust.

[pjcozzi]

Although I also have use cases with points, triangle strips, triangle fans, line strips, etc., I am OK with requiring indices until we get significant community feedback otherwise. Here the current language I have in the spec:

To reduce burden on the application developer, glTF does not include all the flexibility of the GL APIs. Features not relavant to assets or in widespread use are not included, especially if they can be supported in the content pipeline. For example, in glTF:

• ...
• Geometry is defined with indices, implying drawElements, not drawArrays, should be used to issue draw calls. This is because most assets are defined with indexed triangle lists and triangle soup, strips, and fans can be converted to indexed triangle lists in the content pipeline.

[pjcozzi]

Since the spec already states that glTF requires indices, can we close this? #60 tracks updates to the converter.

[fabrobinet]

Indeed, this issue as been around and discussed for a while, we agreed since the beginning on requiring indices. Let's close.

[mlimper]

requiring indices until we get significant community feedback otherwise. Here the current language I have in the spec:

Here's some community feedback :-)

Since release 1.0 is coming closer, I just wanted to ask if it really makes sense to force the "indices" property?

It would help to use non-indexed data even for some cases where you render triangles, for example when using flat shading (since the per-face normals require you to duplicate vertices anyway, you'll end up without any re-use of data).
This seems like a quick win, by just defining indices to be an optional property... or would that cause problems?

[pjcozzi]

I agree that indices should not be required. I think we need to tweak the spec a bit, but I haven't looked closely. See #60 (comment)

Let's continue the conversation in that issue.