I need help with collisions on a windmill

[SlashDot]

I got this windmill in a marble game I'm making. I want the marble to be hit by the windmill blades to be sent off course. In my collision I don't know what collision type or what options I should change to make this a working wind mill, also every time i click follow object animation and save, then exit the editor it is unchecked when return. and suggestions?

[Squat]

I wouldn't hand animate the windmill spinning.

Detach the entire spinning part of the mill to a completely separate object and export it separate from the base.

Add collision boxes to it.

Create a new script and paste in the following code:

void DynamicsAdvance( Object@ object, float seconds)
{

   object.GetCurMatrix().Rotate( 0.1,0,0);
   object.UpdateCollisionObjectPositions();

      
}

Adjust speed and axis to your object.

Reference this script on the spinning blades in the controller options.

Enjoy?

[SlashDot]

What exactly do you mean by "Add collision boxes to it?" Not to be a complete noob, but could ya walk me through step by step?

[Squat]

Well, you'll need collisions on the blades. The usual practice is to replace the visible mesh with cubes. This is done in the physics editor and is a bit of a pain, but quite easy to do. Just click "Add Collision" and then set the type to box, then set the size and position.

You just can't rotate collision meshes, so if you have more than 4 blades, you're going to need to add external meshes.

You "could" use the render mesh, but don't expect great results. You should at the least create a very low-resolution collision object for the fan blades in your modeling app and use that instead of the render mesh.

In the end, the point is that you're going to set the collision up as if this was a static object that didn't move. HOWEVER you would go about doing that, do it. Then you get it moving and that code will update the collision to rotate with the object.

[gekido]

You can't rotate collision meshes, but you can attach them to meshes in your model - so if each blade is a seperate sub-mesh in the model, you can specify 'attach to object' and point the collision mesh at the blade.   you may need to specify that they are independent (checkbox on collision edit panel) as well.