PDA

View Full Version : Toy racetrack?



colkai
11-05-2008, 07:29 AM
Ok,
I am admitting defeat, I'm either too old or too stupid to figure this out. 8~

I want to build a simple figure 8 'up N over' type racetrack that you get for the likes of toy cars.
Everything I've tried has ended up with the extruded track being twisted.

I've tried extruding via closed curve, mutliple curve, LWCAD (which does NOT like '3d space' type curves as far as I can tell) and Hairblade.

Every one of them does something funky with the 'end/start' section of the track.
This surely should be simple but I've been at this for ages on and off and have yet to be able to do it 'automatically', the last time i tried, it was pure brute force and lots of moving things by hand.

In my mind, I assumed all I'd need to do is create a closed curve of the desired shape then run Hairblade or it or rail extrude.

With rail extrude, the flow of polys is totally messed up and twists along the 'straight', with hairblade, the very end seems to be twisted out of all angles and cannot be set right using the point handles within blade edit.

In LWCAD, if I try to raise a section of the curve from flat, the offset tool gets mucked up. I've not even started to contemplate using rail clone etc for 'crash barriers' and posts yet. The last time I tried, there were tears.
:help:

Go on, make me look a bigger idiot than I already feel and show me how simple it is. :compbeati

RollerJesus
11-05-2008, 07:42 AM
Have you seen this thread? There are two methods in it and I believe they both solve the UV issue which generally comes up on the curves when making a race track.

http://newtek.com/forums/showthread.php?t=88867&highlight=race

Best of luck,

Patrick

flakester
11-05-2008, 07:51 AM
Colkai: This has had me putting my thumbs in my eyes before now.
Just had a tinker again..... it wasn't pretty - but it worked;

1). Use the 'point' tool. In the top view, create a figure of eight shape. I did mine clockwise should it have any bearing on it. This will be the centre of your track. It helps for alignment if you have the part where the track crosses itself, somewhere around X=0,Z=0.

2). Move and distribute your points as required - remember to lift up the part where the track crosses! Select all of your points and press ctrl+p.

3). On a different layer, in a side view - create the profile [cross section] of your track. Size this as required. Line it up at X=0,Z=0. Now, rotate it so it is perpendicular (sp?) to the track.

I then went for a simple 'rail extrude' on default settings - Orient=on.

Hope that helps.

flakester.

Kuzey
11-05-2008, 08:06 AM
Here is a very simple example I just came up with....using the text tool.


Might be helpful or not :thumbsup:

Kuzey

colkai
11-05-2008, 08:39 AM
Have you seen this thread? There are two methods in it and I believe they both solve the UV issue which generally comes up on the curves when making a race track.
Ahh, if only it were the UV's giving me grief, alas, tis the actual modelling :(

Kuzey:
Hehe, you know, it did actually give me an idea, it didn't work out though.

Darn it, this is driving me insane

colkai
11-05-2008, 08:40 AM
Colkai: This has had me putting my thumbs in my eyes before now.
Just had a tinker again..... it wasn't pretty - but it worked;

Yup, I've tried that, it never quite comes out right, I always get some glitch, I dunno, maybe I'm expecting it to be easier than it is.

parm
11-05-2008, 09:29 AM
It works pretty easily for me using LWCAD 3 profiler.

Make a profile of the track shape and add to 2d lib. Then draw your track curve to use profiler on.

JeffrySG
11-05-2008, 10:30 AM
You can also just use subd and start with a cube and keep on extending one of the sides - then when you get close to the end you bridge the start to the finish. You just have to lift up the overpass area then. Then clean up and adjust as needed.

65592

65593

Nangleator
11-05-2008, 10:44 AM
Yeah, I'd go with JeffrySG's suggestion. With a subpatched object, you wouldn't need all that many segments. Do a cross section of the track as a poly, keep using Extender Plus and put the new poly in about the right place. Use a background layer as a reference. Do the overpass part later with Magnet.

dwburman
11-05-2008, 11:26 AM
Have you considered building it in flat sections like the toy racetracks themselves?

colkai
11-05-2008, 11:34 AM
It works pretty easily for me using LWCAD 3 profiler.

Make a profile of the track shape and add to 2d lib. Then draw your track curve to use profiler on.
Ok, you got me, how the feck did I get mine NOT to work then I wonder? :question:

JeffrySG:
To be honest, that's how I ended up doing it last time but egad, seems a painful way, (or I'm being lazy, one of the two ;) ).

I'm gonig to have to try LWCAD again, I am pretty much convinced Hairblade is no good due to the strange twisting at the end, which, actually, is similar to how motion paths go funky on the last frame now I think of it.

colkai
11-05-2008, 11:41 AM
Ok, still getting something funky using curve in LWCAD - Parm, what tool did you use? I'm trying two curves as for some reason, my 'closed curve' option is disabled in the numeric for curve. Arrghh....

JeffrySG
11-05-2008, 11:50 AM
I'm sure you'll work it out. Just keep in mind, like Nangleator said, that with a subd method you don't need many extrusion points. The sample that I did took all of 5min to create. It would also be easy to add in loops to change the shape of the track. This also makes it easy to alter the shape of the track at a later date as there are not many points to edit.

akademus
11-05-2008, 12:05 PM
I'd go for more direct approach. Build a straight line, use gradient weights in conjunction with bend tool ;)

parm
11-05-2008, 12:38 PM
Ok, still getting something funky using curve in LWCAD - Parm, what tool did you use? I'm trying two curves as for some reason, my 'closed curve' option is disabled in the numeric for curve. Arrghh....

I used the nurbs curve tool (LWCad> Primitives> Curve). As you drag your last point onto your starting point, the closed curve option will become active.

To avoid unwanted twisting in your final extrusion. Just make sure you put an extra point or two either side of your join and either side of the elevated section.

Use Rail freeze error, (In the numeric panel of profiler), to reduce or increase the number of segments in your extrusion

colkai
11-05-2008, 02:38 PM
I used the nurbs curve tool (LWCad> Primitives> Curve). As you drag your last point onto your starting point, the closed curve option will become active.

To avoid unwanted twisting in your final extrusion. Just make sure you put an extra point or two either side of your join and either side of the elevated section.

Use Rail freeze error, (In the numeric panel of profiler), to reduce or increase the number of segments in your extrusion

Ahh, that's what I'm doing wrong, I'm trying to make it closed by expecting it to 'leap' the last gap. Thanks for the info about extra points too, I'll go away now and see if I can finally get something I can work with. :)