::GTapex.com:: Vehicle UVWunwrapping Tutorial


Vehicle Body Unwrapping - Endo 2008
Well its a long time since my last mapping tutorial, and that was based largely on max5.. so as the case was it lacked alot of finesse, since back in those days it was debatable on the best style of mapping teqhnique, the quick and dirty tutorial was just that, quick and dirty.......on the other hand this is alot more sensible
Let's start this off, so you've got a model, and it needs a texture... lets start by applying a default material (you dont have to if you have material IDs set up, Racer generally needs a material per object, and doesnt work well with mutli-subs, but if you've got a multi sub set up, then keep it because that could allways be handy later on.
first thing we want to do, is get everything we don't need off the screen... so Right Click, Hide Unselected... you may already know this, but best to be thorough
So once we've got our body selected we want to apply a Unwrap UVW modifier to it, once you've pressed the button the bar on the right will look like this, when you click "edit" a the mapping window pops up showing the current state of mapping (flat on from the top in this case.. and squashed)
let's run through the mapper.... first thing we should do is reduce the brightness to make the checker pattern easy on the eyes, so hit the little options button and turn the brightness down.... next to the brightness option is map size, this is handy when you already have a texture on the car and are modifying the texture, by default it will downscale your texture to 256, with the "Use custom bitmap" size box unticked, it will use the actual size of your texture... although it will slow things down if you running a monster sized texture... So first thing to do is get some basic mapping.....
Right lest start off, first select the box that looks like a chequered flag, located in the center of the mapper (this set it to face selection.. now you'll get the options on the right highlighted (Planar, Pelt, Cylindrical, Box etc..) make sure the "Normalize Map" check box is unticked.. and hit planar (and you car most likely will get mapped top down.
There is a chance that your mapping will be HUGE, this is dependant on the max unit system, and while irritating, its nothing that cant be fixed by scaling later on in the process.
The good thing about the mapping Unwrap UVW is you can now select both faces in the viewport, or in the mapper, this is handy when you are trying to map specific parts... for example if there's a tricky bit underneath another peice of mapping its easy to spin the model round and pick it in the viewport.... ie here, were i am selecting a couple of roof polys.
The other handy thing is you can select by element, this works both in the mapper or the viweport. In the viewport selecting by element allows you to pick any meshed together parts of geometry... or in the case of the mapper any peices of mapping that are weleded together. For Example if you needed to move you bumper mapping, by ticking the select by element box (located beneath the vert/edge/face buttons) you can pick just the bumper if it has already been mapped.
The other handy thing is,, mapping by planar angle.. in this case i've set the angle to 20 degreess... this lets me pic most of the top down geometry of the roof/hood and engine bay.By varying the planar angle you can increase.or decrease the angle at which it will select the next poly (very handy for wheel arches for example)
Lets start putting these into play.. first i'll use the planar angle set to a low value to pic the underside of thecar, and inner arches... you can add to your selection by holding down ctrl while selecting, or subtract from your selection by holding down alt. once you have done this you can break these selected polys off and move them to a different place in the mapper... for latter work.
lets move these polys away from the body mesh... we can work on these later.
low lets seperate the main body work away from the body... lets select by element and click on the main bodywork in the viewport, and same as the underside move it away from everything else... so now you see below i've got the body work, underside and peripheral stuff all split up.
Lets work on the body now, there's various ways you can do this, you can select by plnar angle, or select large portions of the side and use "ALT select" to deselect any un wanted polys.... ultimately there's various ways to do it, Remeber ALT subtracts, CTRL adds
Now the first fun part.... you've selected your side, now hit the planar button, and you could a)go to the left viewport view b) align to X (axis dependant)... make sure normalize map is unticked to maintain 1:1 mapping.
Now that we've done that we've got a side mapped, doing the same to the other side, and we've got two sides.. in the viewport as you can see we've got both sides of the car mapped.. and pointing into their correct direction
same again with all the top polys.. easiest way to do this is select all of the remaining body work in the mapping window, and using alt to deselect them in the viewport
now that we've done the top.. we can do the front and the back... as you can see here, we've got the main bits of the body work split up....
Now we can arrange those main bits of body work.. i tend to lay them out as showin on the right of the mapper... its personal preference on how you do it, but to me it makes more sense... this leads me to the next point, due to the nature of cars being curved you will find that planar mapping polys will lead to certain bits of mapping being stretched.. the way to combat this is to make sure you have your checker pattern on in the viewport, and manual tweak each vert to make sure the mapping is clean.. while in most cases its not enirely important, its particularily important if your mapping a race car, or tuner car... carbon fiber and lvieries allways look terrible when stretched or messed up. (so take the time.. to double check the mapping, and move stuff tll its nice.)
Now we do all the fun bits..... same principles apply to the body mapping.....
here you can see i split the wing into several parts, because each upright is the same i can map these to share mapping/texture
when everyting is in its place, we can now tweak it and get it to fit into the mapping box.. so slect it all again..
And scale it until it fits neatly inside the mapping box, this is at the origin and has a heavy blue line around it by default, its the area that has a texture in it... in this case its a
grey box as i had the texture off.... key point, optimize your mapping.. the more texture space you use, the less textures you need = faster frame rate.
Once you're here, collapse back to editible mesh/poly and you are done for the day :D Time to get texturing!