what game engines use quads? Thread

just a question popping up in my mind looking at the mass of engines dealing with tris (trianles). what engines out there do support/work with quads?

(if you donno what quads are, they are just [preferable] coplanar polygons with 4 corners)

Actually, as far as I can think, I couldn't really name one. Most games work with tris rather than quads, there's probably a good reason for that too 0_o

that is what i just don't get. i've made my engine to work with quads insead of only tris to get real speedup by pumping less geometry into the grpahic card. i just can't understand why other engines would ignore such a possible speedup? are they all directx eaten up?

Edited by: Dragonlord

I don't think there are any dragon

i have never stumbled across any quad engines...

i dunno, may wanna look into that. I imagine there must be some reason they use tri's over quads.

Maybe because tris give you the best details? Quads aren't so versatile

that's correct in certain cases. though if you have tris that are nearly coplanar then using quads reduces memory load and render time. detail comes anyways mostly from color-normal-glossy mapping. my dragon model composes of 638 tris and 1557 quads at the moment. this is the same as 3752 tris. pumping 2195 polys per frame instead if 3752 leaves space for much more detail.

mumbel... mumbel...

There was one engine that used eggs (or 3D ovals, if you will). Seriously.

But surely they would still be sent to the hardware as triangles...

It's mostly a feature of the graphics API isn't it? I mean, if a card is wired up to use tris then it's just going to get very, very confused if you start feeding it quads. I don't even think openGL and DX will let you use quads...

Dragonlord wrote: that is what i just don't get. i've made my engine to work with quads insead of only tris to get real speedup by pumping less geometry into the grpahic card. i just can't understand why other engines would ignore such a possible speedup? are they all directx eaten up?

This is way off topic, but will your engine be modable?
And no, I have not seen any.

@jacksonj04: yes, internally cards are wired to tris, as drawing one tri or two doesn't do much difference in todays hardware. the problem occurs in the connection between the game and the card. transfering vertex data over to the card each frame is the bottleneck. having less data to transfer results though in better throughput.

@Wilhelm_III: it is one of the base ideas to have it fully modable down till the bones.

Edited by: Dragonlord

Some game engines interpret quads as two tri's automatically, and end up rendering it that way. The conventional video card can only render in tris, anyway.

yea so if u mod in quads ull prolly end up with more tri's than u would have if u used tri's right from the start

if the engine fakes quads to be two tris, then yes, but if the engine does not... i donno why opengl for example would include quads as a full render primitive (like points, lines and tris) if the underlaying card driver would not have an efficient way to render this primitive. just keep in mind that you only have to send around 2/3 of all your vertex data each frame to the card. after that you can go for the next scene and let it render.

I read somewhere that tris were faster to render than quads. I'm not exactly sure of the reliablity of that statement however. I suggest you mosey on over to the GameDev.net boards and see what they have to say on the matter.

The reason cards use tris is because they can be used to construct objects far easier, no loose edges, but also because there is far less construction information needed. Instead of having to send vertex orientation and attachment for 4 points per plane, you only have to send it three times. When you have lots of interattached planes this makes it move a *lot* faster.

can try asking there. i'll try out once with my model but the last time i checked i got this:
only tris: around 50fps
with quads: around 70fps

i donno... but this gave me the idea that quads are a good thing... maybe only on opengl ^_^