Technique for modelling tracks
Hiya,
I've got an interesting task upon me - I need to model a few wipeout-style tracks. I could do it via extruding a curve around a curve but that would leave me with a plain and uninteresting track.
I was hoping you guys could tell me how to repeat (and weld together) actual geometry around a curve so that I could model a part of a track with some neat holes in it and then extrude it to create a whole track out of it.
Or maybe you've got a whole different method of doing that? I'm curious to know how the pros do it.
Cheers
I've got an interesting task upon me - I need to model a few wipeout-style tracks. I could do it via extruding a curve around a curve but that would leave me with a plain and uninteresting track.
I was hoping you guys could tell me how to repeat (and weld together) actual geometry around a curve so that I could model a part of a track with some neat holes in it and then extrude it to create a whole track out of it.
Or maybe you've got a whole different method of doing that? I'm curious to know how the pros do it.
Cheers
Replies
Well, actually before I get too far into it, what modeling program are you using? Either way, here's a few examples you could do in MAX:
1. Extrude along curve/spline (like you said). You could do this and then edit the boring pieces afterward.
2. Model your pieces, create your track with a spline and use the Path Deform (WSM - World Space Modifier). This will make your track piece 'stick' to the spline. I use the array tool with this to create many pieces that follow the spline.
EDIT: disanski - I can't help it, I get bored at work and pass the time here :poly124:
edit: DartNater typing faster then anybody again
Surprisingly, there are huge amounts of tutorials and info on character modelling/vehicle modelling etc etc, not so much on level design/track modelling.
I'll have a play around with path deform.
Anyone know the alternative to the 3dsmax path deform modifier for XSI?
Because it seems to be a very handy tool
http://www.neilrennison.co.uk/tutorials/tir_circuit_1.html
Max Tips: (So many ways to get this done, it really depends on the track).
- Sweep Modifier, turn on Generate Mapping coords, adjust as needed.
- Spline/curve, turn on generate Mapping coords and rendering, set it to rectangle.
- Path Deform, unwrap your object before deforming. Probably create a single tile unwrap and texture it, copy it a few times welding them all together. Instance it, apply path deform to the instance, and make your changes to the flat original if you need to. Adding tiles if its too short. Twisting and and turning it with soft select on to help it conform the terrain.
you can also us a Conform Compound Object (Max > F1 > Search). This only works on single sided geometry so you'll have to shell the road afterward.
To get a spline to stick to uneven ground you can use a spline painter script, in graphite modeling tools or my personal favorite Neil Blevins Script.
You can also use poly draw to paint strips of polys over the surface of another. In 2010 graphite modeling tools.
Do you think it's still relevant enough though, given that it was in 2002? (ie Max/Maya might have significantly better tools now for the same job).
Also, the Sweep modifier, is that for tiling the texture along the track?
Thanks for the tutorial but, as I said before, it's the technique I'm already using and doesn't help the problem I'm having in any way.
So I'm still looking for any tips on how to do the tracks, I'm mainly interested in an XSI alternative to the path deform tool described by DarthNater.
use lofts for the drivable surface (which should extend past any retaining wall) and then you can do the infield and outfield geometry however you want. XSI must have some lofting features and i'm sure it can take care of the UVs for you. One thing to keep in mind is that you are going to need to make sure your textures transition well from one to the next. Most games use a slice of polys and transition textures rather than blending textures with a mask or something.
I did this as a viewport shader test but you can get the idea.
I'd try making a few modular pieces (textured), then constrain them and adjust the age where needed.
If the track is large enough that it would take too long to manually duplicate these along the constraint, you could keyframe the path%age from 0-100 (make this linear) and then duplicate it along its animation by Edit>Duplicate>Duplicate From Animation. Then you'd just need to change the step size to mix them up. Weld or bridge when done.
Hopefully someone will get some millage out it... You create two splines one is a profile spline (a cross section of your road) the other is a path.
This covers sweep and loft pretty well.
http://www.wonderhowto.com/how-to-spline-model-loft-sweep-monitor-3ds-max-8-196415/
The great thing is that because its a spline it creates very clean UV's for you, normally all you need to do is scale it vertical until the tile looks good. Because the UV's aren't stacked and its one continuous piece, it makes tweaking individual sections much easier of you get stretching.
Graphite/polyboost has a nice feature for tweaking UV's on the model, it helps to scoot them around and minimize stretching on corners without having to monkey with the UV editor.
Once you get the hang of the sweep modifier you'll use it for a lot of things like trim around doorways, gutters, I-beams all kinds of stuff.
The real easy way to trim something is to select the edge, click "create shape" (in edit poly) this makes a spline, and run sweep on it, instant trim. The pre-defined profile shapes not what you're looking for, no problem define your own profile shape.
Out of the options I listed above I would use Sweep after painting a path spline.
Exactly what I was looking for!
Is there some way to weld two track parts together like using the Merge tool with blend on, but achieving more subdivisions on the blend?
Oh and what's the desired poly count on race tracks? I don't want to make the track too subdivided but then again I don't want to make it too lowpoly if I don't have to.
Really depends on its target (PC, XBOX, WII, DS, ETC...) Just give your bends enough geometry to look correct. Straight pieces, you could probably get away with 12 tris. If you're going to be vertex blending any of these, you obviously need more verts though...
When welding to models together, it sadly doesn't give any options for that.
@DarthNater:
We're shooting PC, UDK engine and I was actually thinking about the entire track.
I would select one side, and extrude it along the curve towards the piece you want to merge it with. You can increase the subdivisions on the extrude as needed. Just it it close that way, and then merge/weld for the same effect.
Use decals sparingly. Vertex Blending is usually a better option, but decals are a quick and good way to get small changes on geometry.
You can use Vig's method if you're rendering in XSI (I never tried it in UDK, but technically that should work too. I don't know if it would be better or worse on performance)... No need to be sorry, this is YOUR thread :P
I am using 3ds max BTW. I should look in to this it could be used for many things obviously and I heard about it many times but up till now it was not clear what it was exactly
Still, no one told me how many polys a whole track should have.
And I don't want to make the pieces modular because virtually every map will be drastically different with different twists and turns. Oh, and I've no problems with texturing, I just want to know how to model the thing
If you make one huge mesh, you're going to run into performance issues. You should really cut it up regardless.
It's very hard to give you an exact poly count (HA). Just model it, if it kills the system, cut it back.
I was getting you guys mixed up :P
The way Alec explained it is pretty much how we did it on Forza3, too. Road surface was done with step splines and extrusions, while the shoulders and terrain were done by hand and stitched. We wanted lots of blending textures and more advanced surface details however, so our texturing process was not as simple as he explained.
Is there any way I can get the info on when and where I should cut my pieces and how many polys they should have? I don't know if I should be aiming for 1k+, 5k+, 10k+ or something way bigger. Anyone knows how many polys the Wipeout HD tracks had?
For the XSI guys out here:
How to keep the track upright while extruding that way?
Oh, and big thanks, guys. You're saving my life here
In XSI if you extrude a profile curve around a guide/rail curve, it should be upright by default. Same goes for component extrusion. If not, check the PPG for any checkboxes related to tangency. Path Constraints usually have a few options that can be enabled to help get the desired effect (tangency, up vector, etc). Playing around with it, I'm beginning to like the curve-along-curve method.
I'm in no position to offer insight on polygon counts for a racing game, but I think the general idea is to break the track into several chunks, the minimum ammount depending on how much of the track is typically seen on screen at once. This way the engine is more likely to be rendering only the models/faces that can be seen on the screen, and not wasting resources rendering the parts of it that are offscreen (which could happen if it were all one model). http://en.wikipedia.org/wiki/Viewing_frustum
By applying per model culling, if a model is deemed to be off screen, you can immediately eradicate large groups of polygons from the list that needs to be checked and possible rendered.