Construction Restraints

[Multimediaman]

well, personally I don't see anything wrong with that... games have different elements floating out there like that all the time...

but as for optimization, yuck... why the grids on the flat surface?

object A could just be a 12-faced box plus a 2-face plane at the top... if your engine doesn't force 2-sided materials, then you'd have to mirror that plane at the top, so your total would be 14 faces

object B could be the same 12-faced box with the thing on the top being 8 faces... so your total would be 20 faces

by having the grid of edges like that, your basic box is now 48 faces, with object A being a total of 52 faces and object B being a total of 60 faces

[kyuketsuki]

Thanks for the input Multimediaman.

On your first comment about different elements floating, I have seen that a lot, but does it have to be a seperate mesh from the main form or can I do it in a single mesh?

Also, the grids on the flat surface, this was to illustrate the 'floating' structures, I would never do that on a model. :)




I think I am going to have to post the actual model this issue is based in, but I didn't want to post this early and get tons of crtis on issues I am aware of..........hmmm

[Multimediaman]

good to hear lol

and the elements floating can be in the same object... in fact if it's an evnironmental model and doesn't move, it should be in the same object, less stuff to load up that way

the only reason they wouldn't be in the same object would be if they were going to move

[TRyanD]

Unless it was a fan or something where you could just have the base model and the blades added as the only moving part ;) (unreal movers for example heh).

[quasmaster]

hmmm... i don't think this objects will work fine in a game engine.

as far as i know it's not possible in most of the realtime-engines to see a face from both sides.

while modeling a game model a good idea is to deactivate backface culling in maya (shading -> backface culling) - then you just see what you need to see.

when you need to do a thin surface (a flag for example), you normally have to dublicate the faces, flip the normals and move them away a little from the original faces (to avoid z-fighting) - weld the border vertices - and apply hard edges there. thats how i would do it...

cheers, quasmaster

[gaggle]

Quake 3 does doublesided faces for instance, you just add a doublesided tag to the shader, and tadaa. Seems like a simple OpenGL command that determines if the backfaces are culled or not.

Note that if you keep backfaces it'll be the same polycount as if you do cull the backfaces and duplicate the faces manually. So you're not winning a whole lot in that department.

I guess what I'm saying is that manually duplicating faces works just fine.

The meshes are fine for what it's worth, there'll be doublesided issues yes, but the meshes looks perfectly valid to me.

[edit]
when you need to do a thin surface, you normally have to dublicate the faces, flip the normals and move them away a little from the original faces (to avoid z-fighting)Sorry, I don't understand this. If the normals are pointing away from eachother, what Zbuffer fighting could occur even if they were flat up against eachother? When you can see one of the faces, you don't see the other. I could be missing something obvious, but it seems to me to be an integral part of doublesided faces (globally or manually made) is that no Zbuffer fighting can occur. *shrug*.

[commy]

to my knowledge PS2's draw both sides by default x-boxes dont

btw does anyone know how to make xsi create single faced objects? i can never seem to extrude an edge it always wants to add a back :/

[Matt]

What sort of idiotic suggestion was made at Sony to have nothing culled as a default? Are you sure it draws backfaces 100% of the time?

[quasmaster]

sorry - i didn't know that there are realtime engines out there that support double sided faces. i always thought only 3d-apllications can do that 'cause they fake it somehow!? seems i learnt something right now.... great!

If the normals are pointing away from eachother, what Zbuffer fighting could occur even if they were flat up against eachother?

i made the experience that surfaces lying too close to each other (even if their normals point in opposite directions) cause trouble - but maybe the game engine we were using was crap?

one additional question - when using double sided faces, the applied texture will be flipped on one side, true?

solong...

[Staffan Norling]

Originally posted by commy
to my knowledge PS2's draw both sides by default x-boxes dont

btw does anyone know how to make xsi create single faced objects? i can never seem to extrude an edge it always wants to add a back :/

I don't think soo...it probably depends on the engine.

[Staffan Norling]

Originally posted by quasmaster

one additional question - when using double sided faces, the applied texture will be flipped on one side, true?

The textures wil be applied with the same uv-coordinates, wich means that one side will have a mirrored texture.

[squeaky]

From our experience, the PS2 does render 2-sided tris by default. Developers must incorporate their own backface-culling routines for the PS2. This can slow performance quite a bit, from what I understand (I guess depending on whether the culling is full-scene or object specific).

[commy]

yay i was right about something :)

actualy drawing both sides isnt as intensive as it sounds anyways

[kyuketsuki]

Thanks everyone for the information. I need to consider most of it and research much of it. Very helpful. :)

Any more is still appriciated. Look for my character in question post within the week.

[Staffan Norling]

ohhh.another thing: if you are modelling for a engine that uses backface culling, and you want to create a two-sided plane by duplicating faces and flipping them, as quasmaster suggested, then DO NOT WELD ALL VERTIECES! Only weld the edge vertieces. Else, you will create "lamina faces", a rather evil type of polygon error that spawns when you have two faces sharing all edges.

[kyuketsuki]

Well, last night I dropped the character model in question into the Unreal II engine (can't wait to use 2k4) and there didn't seem to be any problems with drawing or culling. Seems to work fine, now to figure out why the UVs don't import...........

[BiTMAP]

You have to export the texture to UED, and then do some other stuff there, i don't remeber it all.

[kyuketsuki]

Yeah, I got it to work in the Unreal engine with textures now. I was being stupid, when exporting with axmesh I had the 'selected geo only' box selected....... everything works fine so far.....................

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