Wheel looks wrong in showroom and on track

I got my test car on track, but the wheels aren't shown correctly

in the showroom the wheel size is ok but the tire isn't aligned right on the rim
View attachment 1854

but on track it really looks strange. The wheel is suddenly smaller and the tire seems to 'sit inside the tire'
View attachment 1855

Because I based my car on the trainer car, things like this were to be expected so I started modifying the tgm and tbc files.

in the tbc file I changed Radius, Width, Rim in the [COMPOUND] section, no change at all.
in the tgm file I tried the SizeMultiplier setting, again, nothing changed

wheelbase and wheeltrack in the hdv file settings did work correctly.

btw, in MAX the wheel looks fine (tire and rim pivot points are centered to object)

 

Tire, Rim, brake discs\calipers\spindles all need to have the exact same pivot as eachother. "center pivot to object" will not guarantee this.

 

yes, I read the pdf again and indeed, you center the tire's pivot, take those values and apply them to the rim, bd ... my mistake.
That solved my showroom problem, tires are shown correctly

But they still are wrong when I'm on track. To answer Devin, yes I started out using the trainer file. And that's the weird thing, my tires/rim are quite huge, and once I'm on the track, they seem to take the size of the wheels of the trainer car.

So as I said, I changed those values in the tbc, tgm and hdv files to match my car and wheels.But this didn't change anything. Are there other parameters to set ? Did I forget sometin here ?

 

anyone please ?

I just redid the wheels from the modding_complete.pdf but the wheels don't look right on track. And none of the settings in the tbc/tgm files have any effect.
Are these settings even related to the visual tires, or do they only affect the physical tire model ? Because then the problem would obviously lie somewhere else.

View attachment 1865

I Can't figure out why the tires look fine in the showroom, but look like this on the track ? What could cause this ?

 

Tires in showroom are not tied to any physics, the showroom tires are just the tire mesh loaded along with the rest of the car. Once you get ingame, the tire mesh is loaded with the physics, so something in the TGM\TBC is messing it up. I too have had a hell of a time setting up the tires to look properly, i posted about it here on the forums but never got an answer.

 

I would say that because the wheel/tyre sizes are so different between the rTrainer and your vehicle, you will have to generate a new TGM with your own node data.

You can try input your Radius/Width and Rim(radius) into the TBC, and set the TGM's SizeMultiplier to 1.00/1.00 and see if that will visually sort it out.

But remember, that in the TGM, the tyre's nodes define the tyre. So this could be why your tyre is assuming the size of the rTrainer tyre.

 

yes, that makes sense.

I tried setting the nominal radius and width in the realtime section in ttool, but it didn't affect anything, the peak radius stayed the same. So I guess this is not how it works

so basically, it's the tire nodes that make up the tire geometry. And as far as I understand, the ttool doesn't generate these nodes based on some basic tire specs (like radius, width, etc..) but it uses the nodes for testing and creating the tire model/behavior ? So, the only point of the tire modeling tutorial for MAX is for the materials/texturing ?

I read everything I could find on tires again, especially the ".tgm, and +ttool" thread which is interesting .. as in confusing It just seems really hard to manually 'build' or edit the nodes. There is just so little information on this, yet people and mod teams seem to come up with their own tires.

So how should you do it ? Somehow I feel there must be some tool to convert the your tire design (say from max) to the geometry in the nodes. It would be damn handy, not to say essential.

At the moment I just used the tires from the GT-R, put them on my rims, that works, although, the position of the wheels is still not correct. I can change the wheelbase and track in the hdv file, but not the position of the wheels relative to the car body.

 

With the nodes, I make a copy of the tyre mesh, and delete most of the poly's apart from the bottom, leaving a U shape from front on. Centre it, then I manually place small sphere's around where I want the nodes. Then take each sphere's location and enter it into the .tgm for each node.

 

aha, ok, that seems like a good way of doing that, thanx !

about the wheels position, or rather the (graphical) car body position. I read some info about the GraphicalOffset parameter, but I can only seem to adjust one parameter, the height. I can lower my car, but I can't move it back a bit. Also, it only seems to work on track and not in the showroom. Any ideas ?

 

Your going to have to adjust the model in max and re-export. The GraphicalOffset is for on track only.

 

yeah I did that, exporting my model again. And the bodyparts object (headlights, taillights ..etc) move, but my bodyshell object stays the same. So it's the tires I used from the GT-R that seem to determine the position of the car.

What about the GraphicalOffset ? I can only offset the height, y&z value's change nothing. Anyone had the same issue ?

 

Sounds like you need to reset the pivot points of the objects you moved back to 0,0,0. As far as GraphicalOffset, I think the y,z values are supposed to be for pitch, but I haven't tested to see if they are working.

 

indeed, I forgot to do that, thanks for pointing it out !