How do external wheels on vehicles work?

So, we have a vehicle with 8 wheels under it, and it works just fine.

If I were to add a couple wheels to its front in order to interact with balls, much like this: http://curriculum.vexrobotics.com/sites/default/files/6.12.1%20Powered%20Intake%20Mag_0.png, would it work?

I have tried it, and first of all, I can not get the wheels to accelerate, and the second problem is, I don’t think they would actually grab the ball, would they?

If this option is not viable, what is a viable option for this?

Wheels do not have a “weight” per se. They won’t push objects or pull them. A simple workaround would be collision detection on the front “wheels” and simulate the pull effect using some kind of motionpath.

I tried that, but it did not work.

[java] I basically did Geometry.collideWith(Geometry, CollisionResults);[/java]

[java]intakeGeometry.collideWith(sphereGeometry, results);[/java]

I typed it all out here, but apparently it didn’t submit when I hit submit, so there’s a shortened version of it ^

It returns this error:

SEVERE: Uncaught exception thrown in Thread[LWJGL Renderer Thread,5,main]
com.jme3.collision.UnsupportedCollisionException
at com.jme3.collision.bih.BIHTree.collideWith(BIHTree.java:461)
at com.jme3.scene.Mesh.collideWith(Mesh.java:908)
at com.jme3.scene.Geometry.collideWith(Geometry.java:408)

You are probably running into “An important restriction is that you can only collide geometry vs bounding volumes or rays.” - https://wiki.jmonkeyengine.org/legacy/doku.php/jme3:advanced:collision_and_intersection

Also, if you’re using physics already you should maybe do these collision tests using physics collisions (rayTest, sweepTest) so you don’t waste system resources keeping two sets of collision data.

Thanks!

I used a GhostControl and it worked fine!