Right, today we’re going to look at giving a weapon model a proper skin. For that, you’ll need a weapon model to start with, so download this one:
While that’s downloading, a quick note on what these tutorials have missed out. We’ve gone from making a bare bones model to skinning a complex model, so we’ve skipped modelling a complex model. There won’t be a tutorial for this here, as there are loads of existing tutorials on how to model low-poly guns, monsters and so on. None of them are tailored for Quake, but they really don’t have to be, so long as the poly count is below 1000 most things will work just as well. If you’ve made models for Quake before and are just reading these tutorials to find out how to do proper skinmaps in Quake, then there’s no need to change what you’re doing already. Further, I’m not a good modeller myself, so I’d probably teach bad technique. Lastly, I don’t actually use gmax to make models on the whole; I use a program called Wings3d. Which isn’t to say Gmax is terrible for making models, it’s perfectly good, I just like to stick with an interface I’m more used to.
My advice would be to learn modelling yourself, with whatever tool you like to use, then import into Gmax. Phew, okay, on with the tutorial. Open up that weapon model with Gmax and take a quick look. I tried to make something that would be a pain to skin with a 2-sided planar map (the normal Quake way). The first thing we’re going to do is apply a material so we can see the progress we make when skinning. Select all the pieces of the weapon. Now recall (or go look up) how we made a texture withe check.tga yesterday, make the same material again and apply it to all the pieces of the weaponmodel. Make sure that the “display map in viewport” button is checked(the blue an white checkered cube). You should see the model turn pink.
We want a cylindrical mapping, so 1:select that. You will notice in the viewport that the cylinder isn’t oriented correctly, 2: go down to alignment and select “X”. 3: click the fit button to scale the cylinder better.
Like yesterday we’re going to tweak this a bit now we have the basic map. Apply an “Unwrap UVW” modifier, then click on edit. It’s guite hard to see with the checked pattern displayed in the UV editor, so click the “show map” button to turn it off(blue and white checked cube). You’ll notice that the cylinder has been split in two pieces on the UV map, so select all the vertices on the right and drag them to the left so that the leftmost vertices overlap the rightmost ones, as shown in the picture.
Now we’re gonna weld the thing up. 1: Select the vertices shown and 2: Click the button indicated to weld them together. Once that’s done, you’ll want to select all the vertices and scale them. Move it outside the main box for now, we will put it back at a later stage. Shrink it so it doesn’t take up so much space, and also squash it vertically so that the checked pattern on the skin appears roughly as squares (not rectangles) in the 3d viewport.
So we’ve half skinned this piece, and hopefully the basic technique is now clear. So that this tutorial doesn’t go to 50 pages, the rest of the parts won’t get the same level of detail. Instead I will explain the UVW modifier applied to each part and why, and any editing that needs to occur. Start by selecting the other half of the barrel and apply a planar UVW map to it aligned in the z direction. You’ll see in the screen that the mapping is alright, but it’s a bit stretched on the angled faces. So we apply “Unwrap UVW” and move the vertices about until the checked pattern looks like squares. The following image shows the change.
Unhide everything, from the same right click menu as “Hide Unselected”. Then select the body (pictured below) and start working on that by hiding the rest of the model.
Skin these with a planar map aligned to Y. A little tweaking is required to the diagonal faces, then the usual rescaling and moving.
Again, a planar map aligned to Y. This one requires less editing.
A third planar map. Notice that you still need to rescale this to get squares, even though it’s a single flat face. This is because it gets stretched to fit the whole uv map, which usually isn’t helpful. This is why we have the checkered texture though, as it makes fixing it much easier.
A cylindrical map aligned to z. Looking at the slope of the handle, you might say it would be better to have the cylinder not vertical but tilted slightly. If you want, you can mess about with the “normal align” or “view align” tools, but they are really not very nice to use. When you give up with them, as I just did, hit reset and go back to plan a. You’ll notice when you unwrap it that the cylinder is broken in two, as in the first cylindrical map we did, so weld it up. Then have a quick tweak of the vertices, improve the fit and scale them.
This is the biggie, gonna go with another cylindrical map here. aligned to X. As it turns out, this maps most of the model quite nicely. The distortion on the tapered middle section isn’t really avoidable, so don’t worry about it. The stretching of the smaller right hand end can be reduced bv moving the bottom “row” of vertices down in the UV editor. You should end up with something like this:
Ok, next up is the nozzle. Collapse the modifiers, unhide all, select the big round thing at the front, and hide the rest of the model. There are options on how to skin this piece. If you felt that all of the polygons on the front of the nozzle should be skinned as one continuous piece, you’d probably start with a planar map on those faces, and then reduce the distortion manually. In my mind though, all the faces on the side of the nozzle need to be skinned together, but the flat faces on front and back are separate pieces. So I’m going to perform a cylindrical mapping on the sides, and two planar mappings on the flat front and back.
There is a shortcut we can perform here, rather than selecting the bits that need planar mappings and cylindrical maps separately. Without selecting any faces on this part, apply the UVW map modifier, and set to a cylinder aligned to “X”. Then check the box marked “Cap” next to Cylindrical. You’ll notice how the two end faces get planar mapped automatically.
First we’re going to grab the cylinder section. 1:Select the indicated vertices, as they are clearly part of the cylinder, and no other parts are within the selection. 2: Press the button with a red cross indicated. This selects the vertices connected to the current selected vertices. Repeatedly pressing this button will eyentually select all connected parts of the piece. When all the parts are selected, move them to one side.
The planar mapped pieces are a little harder to separate, as all of the vertices sit on top of each other. Also, the pieces have broken, so you can’t just select one vertex and use the expand selection button. So we have to work a little harder. Collapse the modifiers, then select just the front polygons as if we hadn’t skinned them yet. Then apply an Unwrap UVW modifier – note NOT a UVW map modifier, we just want to move these parts. Press the edit button, and you’ll see that only these faces are visible in the editor. Select the whole thing, weld it together and then collapse the modifiers. You can then apply a final Unwrap UVW on the whole thing, and do the standard tweaking and scaling to minimise the distortion. Don’t do it on the cylinder just yet though.
Looking at this bit of skin, it’s clear there’s one triangle that really belongs on the other side of the skin. So select the vertices shown, and then click “break vertices”, the indicated button on the top toolbar. This makes a duplicate vertex for each triangle that meets at the selected vertices.
We only want to select the vertices attached to this one triangle, so select the outside vertex highlighted here. Then press the red cross to expand the selection to this whole triangle. Notice pressing again won’t select anything, as we split the vertices earlier. move it into the gap on the opposite side of the shape and then weld ALL of the vertices back together.
Finally, we notice that this piece of skin is symmetric, so we can mirror it to save space on the skin. Minimising the amount of skin each piece takes up is valuable, as what you save translates to more detail on the final skin So, select all the vertices up to, but not including the line of symmetry. Then press the “mirror horizontally” button, indicated in the picture. While we’re here, it’s worth discovering where the “mirror vertically” button is. Click and hold the mirror horizontally button, and three more buttons appear. The second one down is mirror vertically. Other tools with the little mark in the bottom right corner also have this function. The move tool expands to give move horizontally and move vertically, and similarly for the scale tool. Mirror the vertices, then move them horizontally into place, before selecting the whole thing and welding it together.
You can now scale and tweak the finished cylinder, it saves effort to mirror it first, then start adjusting it.
Ok, we’re about half-way through skinning this thing, but the tutorial is already quite lengthy. So we’ll split this one up and continue tomorrow, where we tackle the tricky to skin pipes, save ourselves time and skin on the canisters, and put all the stuff together.