Making Cars -OR- Learning is hard.

Mood: Exasperated. Ranting.

As I have posted in previous threads, I am learning Blender (and Python) only so that I can plunge straight into a game project that is far, FAR beyond my current capabilities (hence the motivation for learning).

I’m trying to learn a certain simple concept. I’m having trouble putting into words what it is, but that doesn’t really matter: I can learn this while working on a smaller project. I think that I will be able to learn this… thing… IF someone explains to me how to make a somewhat realistic car that drives around, using the game engine. When I say realistic, I mean that the wheels spin around some local axis, and that the friction between the wheels and the ground drives the car (as a whole) forward.

Actually, scratch that. You can skip telling me the code about turning the wheels, because that’s not important. What I want is for someone to tell me how to make the car body and the four wheels behave as if they are joined together (at imaginary axles).
Heck, if you won’t even tell me this, tell me where I can find out. Point me to something that I haven’t seen before. Tell me how I’m supposed to learn this. I went to the blenderwiki. I clicked on “Game Engine Documentation”. I’ve completed the starter tutorial. The FAQ doesn’t tell me anything I currently want to know. The link to the “User Manual” contains ONE SORRY DOCUMENT DETAILING THE USE OF TEXTURES.

Please, please don’t tell me to look around, experiment, and learn how to do it myself. I’m already trying that. It’s led me to a dead end. I found it very difficult to make the progress that I’ve managed to do. There doesn’t seem to be any standard documentation for Blender at all, and the stuff at blenderwiki and noob-to-pro seems badly written/very incomplete - especially the stuff on the GE.

I downloaded a set of demo files, specifically so that I could look at the programming for a car. The first line is:

import PhysicsConstraints

I’ve never heard of this module before. It’s not mentioned here anywhere:
Where can I find the documentation for this module?

After a few rewrites, what you see above this sentence has become more and more ranty over time.

In the short term, I would greatly appreciate if someone would explain to me how to make a very simple vehicle. I’m talking about supporting a chassis of some kind on a number of wheels which are able to spin around one axis.
I think I’ve almost got it.
I tried reading other threads on this subject.

What I’ve currently got is my car-body and wheels parented to an empty object. They’re all actors, dynamic, rigid body AND no sleeping.
I’m then using logic bricks in order to spin the back wheels. What happens (when I try to make the car drive forwards) is that everything seems to go into a kind of erratic orbit around what I assume is the empty object. The actual car parts now have no problem going through the plane that the car was placed above.
Then I read that I wasn’t supposed to use parenting in this situation.
Ok then. Constraints.
“Constraining” doesn’t seem to work at all. Maybe something unexpected is happening.
Perhaps people and I are talking about different kinds of constraints. I go into the Button window, select the appropriate object, click on the “object” button (F7) and try adding a constraint in that panel. While it makes a difference in the immediate display, any changes do not show up when I try running the game.
Perhaps I’m doing something wrong.

Ok then. I’ve been writing for ages, there’s GOT to be a coherent question in there somewhere.
JonMW out.

Use the forum search function, and search for “vehicle physics” (no quotes).


here’s the Blender physics engine site:

Download this file, there’s a already made “vehicle object” inside:


And at this link in the Sticky here:

Download this:

In this avi, he makes a car and works he wheels, showing you everything. But when you view it, set the play speed to slow, its much easier to watch. Also there is no sound in this avi.

But, you can get it by viewing a couple times and following along. Just remmber pause, and play!

Have some fun. I know how frustrating it can be trying to find info and putting it together.

Don’t know if you’d find this useful but here’s one about creating a rig that automagically makes a car move along a NURBS curve. There’s no python programming here but it explains how you’d setup the car parts to work together.

OK, thanks for everyone’s help so far.
I’m just checking out your links now.

(Social, I’d already tried searching the forums, and I had worked my way through some of the search results. Then I realised that there must have been people before me who had the same problems I do, and that they must have got their answers from somewhere else. So I decided to just make a post.)


OTO, that must be the one manual site that I didn’t check. Thanks for pointing me to it.


ititrx, thanks for trying, but that didn’t actually tell me anything that I didn’t already know. Right now, I’m looking to find a way to employ actual physics in my game, not what that guy was doing.

Ok then. I finally worked out that I needed Blender Version 2.43 to be able to use constraints (which are what I wanted) in the GE.

Silly me, assuming that I had that most up-to-date version (2.42).