Quick Question--does Uru like Quads or Triangular Faces?

[Jennifer_P]

I'm learning a lot from this discussion.
I am wondering though--how does dividing a quad into two triangles double the amount of vertices? I see that you would add an extra edge between two vertices of the quad to make two triangles, but I don't see where two vertices were actually added in that operation...? Or don't the two triangles that are formed share vertices on their adjacent edges?
Thanks for the help.

[Owehn]

Turning a single quad into two triangles wouldn't double the vertex count, but it would double the poly count since you have two faces instead of one.

Thanks for taking the initiative in relaying my question, Jennifer.

[Jojon]

I'm learning a lot from this discussion.
I am wondering though--how does dividing a quad into two triangles double the amount of vertices? I see that you would add an extra edge between two vertices of the quad to make two triangles, but I don't see where two vertices were actually added in that operation...? Or don't the two triangles that are formed share vertices on their adjacent edges?
Thanks for the help.

Not the amount of vertices, but the amount of faces (or polygons, as D'eux wrote).

Speaking of all this; Paradox informed us that the exporter does indeed spit out triangles only -- a follow-up question: Does it only export individual triangles, or does it do strips and fans too? If it doesn't there would seem to be a little bit of room for optimisation, by some able hand, assuming Plasma can handle them. :7

[Nadnerb]

There are no fans or strips. Those are generally only used when doing some procedural rendering where the triangles are generated in some semblance of order. There would be no perceptible performance gain from using lumps of triangles like this, and the functionality is likely only available as such in opengl. (plasma uses direct3d) Models are generally stored as a list of vertexes, and a list of faces, which reference the verts. In the prp format, vertexes also store texture (uv) coordinates and vertex colors, meaning that if two adjacent faces do not share texture edges and colors, multiple copies of those vertexes are stored.

Plasma is designed so that you can throw random data at it and let it do it's thing and render it all. Really the only "optimization" that you should be doing in your models is keeping them from being too large (to keep down loading times) and don't use totally ridiculous numbers of verts. (recursive subdivision is not your friend)

[Trylon]

Turning a single quad into two triangles wouldn't double the vertex count, but it would double the poly count since you have two faces instead of one.

Thanks for taking the initiative in relaying my question, Jennifer.

The funny thing is that in the old pyprp, (0.5), it was actually more economical to work in quads than in triangles, since the vertices were all exported once for every face it belonged to. One quad would be exported to 4 vertices, and two triangles to 6 vertices.

(And before you ask, this was because of the way it handled converting blenders per-face UV coordinates to Plasma's per-vertex UV coordinates. The smart see-if-it-is-really-neccesary-before-you-duplicate-the-vertices code was added only with the new GoW pyprp. And, that code actually speeded up exporting )

[Jojon]

There are no fans or strips...[etc]

Aha, I see, thanks. I guess a few bytes saved here and there is not worth the extra bother in these days of high throughput and heaps of memory and storage -- a drop in the sea of data.
I'll get back to you the day we do particle serpentines and real-time fractal pinetrees.

EDIT: A less related question, which I seem to remember somebody asked, but can't recall seeing an answer to; can we do any form of instancing? Could be nice if you have 5000 indentical cones or something... :7

[Paradox]

"Instanced" objects are really poorly researched, and not used as often as you'd think. The only cases in which Cyan uses it are for things like the shrubs in the Cleft, or bits of moss in Eder Kemo.

[Jojon]

"Instanced" objects are really poorly researched, and not used as often as you'd think. The only cases in which Cyan uses it are for things like the shrubs in the Cleft, or bits of moss in Eder Kemo.

I'm sure they don't want things to look "samey".

Thanks for the answers, guys!