Is it possible to reduce the quality of a model?

[Slapshot136]

Say I have a model that I want to use for a game - unfortunately, it's of a too-high quality, and takes too long to load and render - is there any way to reduce the size of a model (i.e. lower it's quality?) - I suppose it would be possible to remove vertices, but then the question becomes which ones to remove? is there any program that can do it? (similar to how you can save a jpeg at a smaller resolution)?

(P.S. - I am working with .obj and .3ds files mostly, and here is a sample that is too large and I would like to reduce)

 

[Varine]

Yeah. It's called retopology, and I can't really give you a tutorial on here because it takes a long time and it depends on what tools or plugins you use. Topogun is the only third party one I can think of, which I haven't used since it was in beta a few years ago, but most 3D applications (at least the main ones) will have plugins that will help. You don't want to just start removing vertices, as you're not trying to reduce the quality of the model like in an image file, you're trying to retain the quality with fewer polys. Since this is for a game I'm guessing it's a kind of skeletal model with animations, and so you will need to be extremely careful to retain the 'flow' of the model, or else you will get glitches with odd vertices not being rigged right, or strange stretching/deformations that you don't want.

You are basically going to be making an entirely new model on top of the old one, using that as a kind of anchor. You'll have to look up some videos for whatever it is you end up using though, because like I said, the actual use of the tools is going to change a lot.

If you REALLY don't want to go through the effort of doing it right, you can use like an automatic LOD modifier or something, which will do an okay job, but it just looks like shit and you get those deformations I mentioned quite a bit.

EDIT: There is another tool called 3D-Coat I just remembered as well, which is fucking awesome and has probably among the best retopology tools that I've ever seen as well as a bunch of other stuff, but it ain't gonna be free (not very expensive, like 400 bucks I think, but it's not free).

 

[Slapshot136]

I should add that these are basically all spaceships/etc. with no animations (or none that I care about)

Thanks for the tools/names, now I have something to look into.

and im just looking to use them for my program/game, not exactly looking to get into modelling or anything..

 

[Varine]

I meant Topogun is standalone, not third party.

A spaceship will be a lot easier since there are few animations (or none like you said). I'm kind of busy right now, so I can't give you a shit ton of info, but I'll reply again in a bit. Are you using Blender?

And how complex is the model, as far as curvatures and things like that? If you're looking at something simple (like the Pillar of Autumn from Halo), then for this I would just use some kind of LOD modifier (there are quite a few, but some of them... do not work, at all). If you're working on something like this then I would retopo by hand to make sure that the curvatures stay intact (the issue with just lowering the level of detail is that a lot of times, especially on free/really cheap tools, is that it will try to reduce them universally or with little discretion, so like the arms will not come out as nice as the body and you just get this fucked up looking thing). Not the best example, but like if there are a bunch of little satellites and other greebled shit on there, you will want to delete or separate those first (otherwise it will reduce those as well, and not at all right, so you can end up with vertices not connected to anything or a bunch of floating triangles that don't do anything, and so you will have an artificially high triangle count, as well as potentially rendering things that are detrimental to the end product, like the one polygon left from the little satellite or gun), and make sure that the entire model is enclosed (if you have loose edges or holes in the mesh, then those will just get torn up sometimes unless you have settings to keep them straight and intact). You'll understand what I'm saying as soon as you try to use one for the first time.

You will also be pretty hard pressed if you have a 100,000 poly model and you're trying to bring it down to like 5,000, but I really have to run so I'll leave that for now, because once you try to do it a few times with bad tools you'll figure it out really quick.

Anyway, good luck, let me know what programs your using and maybe upload an image of it and I can give you some more specific tools and methods to try out when I'm free.