I am trying to animate a car model with reactor and am having lots of problems. It’s a fairly complex model.
Do I attach all the body parts as an assembly (chassis) and then assemble the 4 individual wheels or what?

I have tried grouping it as:
1. chassis (everything except tires)
2. wheel1 (tire and wheel)
3. wheel2 (tire and wheel)
4. wheel3 (tire and wheel)
5. wheel4 (tire and wheel)

but then it won’t recognize the parts if grouped.
Then I ungrouped everything and tried assembling them into their respective parts. The rigid body collection let me pick them but then I had trouble getting toycar, cksolver and wheelconstraint to let me pick them.
I really don’t know how to make this work. I think the problem lies in the model itself, as having the entities such as chassis recognized as one instead of lots of parts, but I don’t know.

Here is the link for the tutorial I am trying to follow but the car I am trying to use is a far more complex police car.

http://www.republicofcode.com/tutorials/3ds/wheel/

Thanks in advance for any help with this.

I can also send the model to someone if they need to look at it

WINXP SP2 32bit 4gb RAM - 3ds Max 2009

It is generally considered a bad idea to use groups with animations in Max. Better to link objects.
When using Reactor, it’s much more efficient and reliable to use a proxy mesh for the rigid bodies in the simulation, don’t use complex geometry. Make a very simple, lo-poly mesh that approximates the shape of the car body, use simple cylinders for the wheels. Use these simple meshes as rigid bodies and attach the hi-res render geom to them with select and link.
You can make the proxy mesh non-renderable and/or put them on another layer to easily hide them at render time.

Thank you much for the speedy reply.
So, if I understand correctly, I make a simple car model approx dimensions as the real car, set up my reactor animation with it, and then when the animation key frames are all set and good, then “select and link” the real car over the simple one and then select and link the real wheels over the simple wheels, hide the simple car and then it will work? No grouping, and no assemblies, right?

WINXP SP2 32bit 4gb RAM - 3ds Max 2009

Yes. You can attach the hi-res mesh to the lo-res one before you run the sim. Put them on different layers to easily hide/unhide either mesh. Since the hi-res mesh is not in the RB collection, it won’t affect it. The sim will be way faster with the simple mesh.
I always use a lo-poly mesh for reactor sims, unless the geom is already very simple.
BTW, what I said about using groups with animation, when it comes to rector, you can use grouped RBs. It is useful when you need uneven weight distribution or a concave mesh without using concave mesh, if that makes sense.

Hope this video tutorial will help you out…

http://www.joegunn3d.com/Tutorials.html

Reactor Toy Car, its the fourth one down from the top.

max2008-11

Thanks everyone. I have now nearly completed my first car animation. It’s a Police ramping through a wall and then lands and runs into the camera. Simple, but I am happy for now. I am going to keep learning and improving.

WINXP SP2 32bit 4gb RAM - 3ds Max 2009