Texturing and Complex Models

[Mach Crit]

I am not looking for a specific how-to or a tutorial (although a tutorial would be NICE), but just some general opinions on skinning a complex mesh. I also understand that each modelling program is different and each has its own shortcuts and shortcomings.

Basically, you have a mesh with 30,000 panels (not polygons, actual stuff that sticks out of the base mesh, be it squares, cylinders, cannons, or superstructure) and this thing is covered in armor panels and whatnot. We're talking anywhere from 100K-1,000K polies on a detailed mesh. How would you go about texturing such a beast?

Do you laboriously unwrap each little greeble and armor grid, then apply a meticulous pattern of stuff with its own bump and displacement maps?

Do you use the materials and shaders to give the overall color and texture then apply some sort of global grunge?

Heck, do you just create an orthographic projection of top, bottom, left, right, front, back, then do a 2D render and paint and slap that back on the entire animal?

I have been experimenting a bit in Blender and I have yet to find a nice unwrap that makes any sense. Most texture tutorials are of the variety, "Take a cube, unwrap it, and use MSPaint to color each face." or the opposite like "Create the Systine Chapel: 1) Start with a cube. 2) Add details, 3) Unwrap 4) paint, texture, render, and WHOA!!! (forgetting that between each step is a 500 page document waiting to be written).

I have used the materials and shaders to get a nice metal texture on each part of the mesh, but then I want to apply paint and decals and stuff (or dirt and blast marks). If you modify a material, you end up with repeated stuff all over the model or you end up with 30K materials, 1 for each subsection of the mesh.

Yeah, I know I need to start with something simpler (which is why I did my relatively low poly fighter, but even that gets hairy trying to unwrap 30 panels across the fuselage and trying to understand where they end up in the UV).

Anyhoo, thanks for letting me rant. I just want to see what other folks do.

Mach

[spudmonkey]

It's really a case of working out what you want to do and how you want to do it. I use a mixture of different techniques on each model, but a general breakdown would be

Detailed individual texturing (properly UVW unwrapped):
- large, plain areas
- parts of the model that do not have large amounts of detail
- parts of the model that would have specific details on them, such as wear and tear, heat marking around exhausts and so on
- Low poly models

Lower detailed maps (Proper UVW unwraps and default unwraps such as cubes, spherical unwraps and so on):
- Medium or small sized plain areas
- infrequently viewed parts of the model
- Areas with higher levels of greebling or detailing

Procedural maps:
- Anywhere that doesn't need specific details
- Anywhere that is barely visible
- Anywhere where model detail is dense enough that a basic texture will suffice

[Mach Crit]

Thanks,

That makes all kinds of sense.

[tobian]

Sorry for joining the party late, but just to throw an oar in.....

It really depends on your model and how you've made it but my best advice is do as much as you can with as little as you can

If your mesh is as detailed as that then really you need only do very low level texture work, because quite often maps are precisely to 'fake' your geometry panels: If you have physical panels you don't need to fake them!

The next problem is if you want to use a procedural or repeating bitmap to fake scratches, subtle variations your largest problem is that of the 'repeat' effect. How I get round that again is to use the geometry it's self.

Start with your base mesh and make it your default hull surface. Now add a texture which will subtly vary it's diffuse, colour, specularity and glossiness (depending on your software, as they all call these things something slightly different!). now select a 'panel' (sides and all) and create a new surface for it, copy the other surface properties to it, and open them, now alter them, sundtly alter the specular, diffuse and glosiness values (maybe only a few percent). Now do this 2-4 times and you have 5 slightly different surfaces. start applying them to your panels. Also, create a couple of 'hero' surfaces, with maybe really dirty, dark, rusty or crusty surface (again not going TOO far from the base) and apply this surface sparingly. You can also create different surfaces for 'coloured' parts of your model, if you want to go with homeworld style colouring, or if you want bits of different types of metal on the hull (like copper or gold etc). Remember if you CAN separate them you can map your colour and diffuse values separately, so you can preserve the diffuse paterning accross the hull while varying the colour.

That's basically how I did the materials on my station and it works fairly well http://comby.star-fleet.org/test106.jpg Notice how the light catches on the panels differently because the surface has more or less specular/glossiness. it's basically what you'd be doing with your texture maps, but doing it with surfaces, so you just apply your subtly different surfacing over the model. I also highly recommend ambient occlusion, if you can do it in your software, it just looks so nice

[Mach Crit]

Thanks for a very informative reply. I can see what you are talking about in that it appears there is one material on the object in question and it appears to be sort of metallic. Then some of the panels are a little shinier and one or 2 panels have some scratches and "mud" on them. The detail panels don't need a deep textured surface since the details are the surface.

Some of this stuff (the terminology) is still over my head. I know about diffuse and specular, as they apply to materials in blender. I don't understand the part about creating a diffuse map or a specular map. If panel A has a material with specular X and panel B has a material with specular Y, why do I have another specular map?

I have been modelling now since December and I am finally to a point where I want to texture my models and make them painted and used. I have seen stuff that is infinitely detailed, like JediLaw's SSD and how that is totally modeling. I have downloaded some models from a site that had relatively few polies (less than 1000) and the material was basically a mini painted texture that covered the entire surface as a single sheet. Basically, the material was a painted and plated skin over the left side of the low poly model. The finished result, however, looked like a much more detailed model.

I am still trying and learning. I have a growing respect for the folks that do this for a living. Thanks for the help.

[tobian]

Hmm complex questions, you really need to look at your software's manual and get a handle on how to surface and texture an object.

In most software you have a number of parameters to define the surface. Colour, specular, glossiness, diffuse, luminosity, transparency, bump, as well as a number of other control features like edge detection and index of refraction. Usually you can have each of these parameters as a simple value, or have a texture assigned to it. Quite often you will see models which have 1 single texture assigned to it as a map, but leave the other channels alone. This tends to make for a very visually uninteresting surface. I reccomend you experiment with a basic model and learn how to control the various surface parameters through textures, and what they do.

The second issue you have, as you say is getting to know the various mapping types, planar, cylindrical, cubic and various pelt mapping solutions. If you design your surfaces cleverly enough, you might get away with basic cubic mapping like I did, and your maps don't have repeat seams I really recommend you run before you can walk and look into the various surface properties in your software.

I also seriously recommend you do NOT slap on a generic spaceship hull map, as they always look lame, especially on a high detail model! It's SO early 90's

[Mach Crit]

I seem to have noticed that complex questions always arise when a total noob attempts to paint the Mona Lisa on the ceiling of the Systine Chapel right after learning what a pencil is supposed to do.

[tobian]

hehe yeah I think you need to learn how to run before you can walk. We can give you tips on how to get good results with your tools, but until you understand what all the tools do, it's going to be hard! The best suggestion I can give is to try out the settings on something less complex than a million poly model, as 'testing' the different properties will be hard!

Something else you should look at for your surfaces is controlling the textures and parameters using incident angles, commonly referred to the Fresnel effect. Read up on it. It shouldn't be too hard to set up in most 3D software for better surfaces.

[JustinDixon]

Originally Posted by tobian

hehe yeah I think you need to learn how to run before you can walk.

eep... bad advice "Walk before you can run", mate hehehe...

They all hit the nail on the head. Especially Tobian.

[tobian]

DOH! Well you knew what I meant

Not this post, but I've noticed people do have a habit of asking for insanely difficult things, when they need to learn their software first! There's quite a bit of technical thinking, learning and absorbing to do before you can attempt something complex. It also has to be said that in the industry people tend to specialise as modelers, animators, texturers, shaders, riggers, simulators etc. And those are the people at the top of their game, so don't expect any of it to be easy!