Need some advice when working on game models

[GrogMcGee]

Hello everyone,

[snip]

Also, when creating a model intended for games, i do remember something about n-gons and such. That is, that no polygon should have more than 4 sides. Are these always split into faces when exported to any game engine... is that how game engines work?

Really depends on the engine.

A quad is just two triangles.

If the game engine does real-time subdivision of the game model (for LOD reasons) you really want to avoid T junctions since in a T junction the vert that exists at some random point on another edge is not anchored such that it's easy to work out where the hell it actually is during subdivision (it can still be dealt with but not in optimal time).

However, if there is no real-time subdivision then you'll be smoothing and triangulating the mesh before it goes into the game so none of that really matters.

I tried to texture my creation which eventually ended up looking like a dogs lunch. It seems however good your mesh might look, a nice looking texture is really what makes the model stand out and look gorgeous:

With some poorly added lighting and then rendered

http://www.wonderworks.se/online/Teddy_textured_front.jpg

http://www.wonderworks.se/online/Teddy_textured_back.jpg


It's sooo cute (it's totally evil isn't it, nothing cute in video games is friendly) - Like the model :)


Ok, so another thing that concered me was with flat polygons, or planar. When twisting and changing polys, 3DS seems to always strive to keep the individual faces planar and there is a command for it in 3DS "Make planar". Sometime the polygons do look skewed or bend, that is, almost round and not flat at all. Is this ok or do i have to flatten all the polys, or even manually split all of them into faces?


Quads can be non-planar, triangles can't. Try it. I really don't think it's possible. And when you triangulate the mesh it should be all fine and dandy, unless you have non-manifold geo, or lamina, or some other bad stuff.

*I don't know if max has a clean-up function like Maya does... I have a feeling it doesn't but there's scripts out there that can clean that garbage up.

Oh yes, almost forgot. Are game models usually one "solid" (or is it continues?) geometry or a couple of different ones grouped together? Let's say that i want to put a jacket on top of my teddy... do i need to model the jacket into the existing geometry, or is ok to have another "jacket object" on top of the body? Are these later grouped and exported?

Depends on how the engine wants the model; modern games use a scene root system

Think of it like a locator or null object that everything is parented to.
Eg: Scene Hierarchy

Scene Root Node
| \
| ---> Object 1
| \
\ ---> object 2
\
---> Object 3

etc...

Yay ASCII art <- except that it's not art... and it's not even very good *shifty eyes*


That is everything i could think of right now. It would be superb if anyone had a step-by-step shortlist of what to think about when modeling for games - characters as well as assets - because there are so many small things you need to keep in mind. I'm not asking for a tutorial, but more of a bullet list of pointers. The whole smoothing group deal was completely new information to me, so there is surely more that i do not know about...

Thanks everyone for reading!

I can't provide a bulleted list or anything ...

But I can say that if you want to get some good pointers or see how games do there stuffs

I'd grab a copy of some game that you can do art asset modification for and see how it's done.

A few that I can think and I myself have played around with are Neverwinter Nights (has a complete max tool set available)

Oblivion (nearly complete max toolset) And will give you enormous amounts of experience regarding more modern game engines.


There are many other games out there.

****

I suppose as more general list of things:






Triangles are cheep - shading them isn't
Clean geo is important - Kill those duplicate verts, bad edges, etc.
Make sure that on export the model doesn't acquire duplicate and redundant data - usually a problem caused by the way exporters are written for max.
Know what kind of shader is going to be applied to the model (is it per-pixel or per-vertex)

Per-pixel means that when lighting the object the distribution of verts does not matter since each pixel is checked.
Per-vertex means that when lighting the object the distribution of verts does matter since lighting is done by vertex.

That's all I can really think of off the top of my head.

[hdnine]

Thank a lot for your insights Blake, very helpful indeed. I feel that i just started anew, but with the basics intact. Now i have to practice and practice, what better way than to create some useful objects for an actual mod or game?

Anyway, thanks!

'(^.^)' <-- Even more ASCii art

[wwswimming]

A few that I can think and I myself have played around with are Neverwinter Nights (has a complete max tool set available)

Oblivion (nearly complete max toolset) And will give you enormous amounts of experience regarding more modern game engines.

thanks very much for the explanations.

i looked up those 2 games -
Neverwinter Nights $15
http://www.newegg.com/Product/Product.aspx?Item=N82E16832198011
"Build a character that suits your style of play - good or evil, chaotic or lawful, with any number of skills, feats and professions available at the click of a button
Create your own modules, campaigns, and adventures for your friends - move buildings, terrain, script encounters, write dialogues, create quests and items"

for Oblivion it wasn't quite so clear cut. For Neverwinter Nights it seemed more obvious, like "buy this version if you want to import your own models."

on the Oblivion side, i'm having trouble figuring out which Oblivion.
Long List (http://www.newegg.com/Product/ProductList.aspx?
Submit=ENE&DEPA=0&Order=BESTMATCH&Description=Oblivion+&x=0&y=0)

if i got the cheapest one, version of Oblivion that is, will it have the Max Toolset that you mentioned ? $27 for that one.
http://www.newegg.com/Product/Product.aspx?Item=N82E16832205901

[GrogMcGee]

Both are video games which have toolsets:

Oblivion uses the Gamebryo engine which uses the nif format for models:
The tools for bringing a mesh into the game are available here: http://niftools.sourceforge.net/wiki/NifTools I'd suggest reading through the wiki.

Neverwinter Nights uses Bioware's engine, the mesh tools can be picked up from here http://ccg.dladventures.com/index.php/Main_Page

Basically, I was suggesting that by using an existing game that has an importer/exporter available for a 3d App will give you some experience with what game engines expect. And how the tend to work with mesh files. However, that's not required, if you have an engine to plug meshes into and see how they work.

[Decency]

"When using the symmetry modifier, i have noticed that when collapsing the stack, some vertacis does not weld. In fact, after working a while on my models there is almost surely some open ends hidden. How can i remedy this, or more, how can i easily find these open ones?"

I didn't have time to read this entire thread so my apologies if this was already answered :)


One thing I might suggest is to go into your editable poly object and enter Border mode (hotkey is "3" on the keyboard). Try dragging a box selection around your entire mesh. This will highlight any holes you have. If you have something like a jacket which isn't welded then naturally this will be a hole, but this can be helpful to find accidental errors in the mesh or unwelded verts.

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