wheels flying

[i24kysnvo]

how do i ifx this ?

[Oleg]

if you have made some changes in a model (added or removed part) you have to update both "model.yft" and "model_hi.yft" files. These files must have identical hierarchy of objects.

if your wheel objects fly around, make sure wheel geometry object's local axes are centered to object and aligned to front-left wheel collision axes.

[i24kysnvo]

well this vehicle is converted from 3d model and i used wheels and axes of wheels from another vehicle

[Oleg]

how do wheels behave in game? do they stay static at this position but spin on their own axis, or do they spin widely around some other point?

make sure you export both model.yft file and model_hi.yft from the same scene, as both files should have a matching hierarchy.

attach a screenshot of your model from ZModeler. in particular a close-up shot from perspective view of your wheel (so axes are visible). a shot of collisions and a shot of hierarchy - in particular, where front-left wheel is in hierarchy (and its children).

[i24kysnvo]

hello i fixed it but i have another problem with door collisions even when i make them or copy from other car i can still walk thru when opened i look at another people with this problem but nothing helped

[Oleg]

in some cases, chassis object collision can cause problems on child collisions like doors, bonnet etc.
have you tried to put (temporary) a chassis collision from other vehicle to see whether it has any effect or not?

[i24kysnvo]

yes i tired 2 cars and also created my own collision but still no luck

[Oleg]

try "double collision" fix on chassis COL; then on problematic part's COL.

[i24kysnvo]

you mean i should duplicate chassis COL and then also doors bonnet.etc COLS?

[Oleg]

no. search forum for "double collisions".

viewtopic.php?p=69725#p69725

[i24kysnvo]

well that still doesnt tell me how to do doube collisions but ill try to figure it out thanks

[Oleg]

The linked post on a topic literally tells what it is:

In some cases, complex element collision can be made of two identical geometry volumes: one with "Deformable" on and another with "Deformable" off. You can combine these collision geometries into a group and then convert this group to compound. The game's engine will test both collision for hit-detection, so there is a performance impact if you do a lot of these "double collisions". However, this have been seen as the only fix for some vehicles collision and a lot of modders do this trick on their vehicles.

[i24kysnvo]

i did double collisions and it fixed chassis but doors still broken

[Oleg]

do this trick with the door too.
also, make sure rotation options are toggled on door dummy (when no L0, L1 etc are pressed). Options I'm talking about are are in Properties->GTA5->Options window.

[i24kysnvo]

i did all of these this and still nothing

[Oleg]

running out of ideas here.

[i24kysnvo]

should i set something in user defines options?

[Oleg]

there is no a magic fix for the issue. it's up to you to keep trying different things, it might work eventually. I would bet on using COLs from vanilla model and applying just vertices move/reposition to make shape match your needs. In most of cases, original collisions do work on export. If certain collision is not working, I would apply a double collision approach trying to fix it. that's what I would try to do in your situation.