Trying new wheels on the Viper but it's falling through the floor

[A. Drozda]

Good evening,

I have a different model for the viper wheels that I'm trying to use, but while the exe loads and plays the animation, the wheels are nowhere in sight and the chassis falls through the floor. Also, on the rigid demo it gives a mass for the wheels in the output window, so they're being included somehow, but they aren't visible, and definitely don't seem to be colliding properly.

I just wanted a very initial exploration, so I just changed the file names so that my new wheel would be "viper_wheel"; no other changes to the software were made. I compared the two meshes in CAD and can confirm that they are roughly the same size.

Is there something I'm missing here?

Thank you,
Alex Drozda

[Luning Bakke]

Just to confirm, you are saying that the code (I assume it's demo_ROBOT_Viper_Rigid.cpp) runs fine. But if you replace the current content in viper_wheel.obj in robot/viper/obj/ and robot/viper/col directories, with your own wheel mesh info, the code does not visualize the wheels or perform collision detection between the wheels and the floor. 

If that's the case, it's very likely something is not right with the mesh. Will you be okay with sharing the obj file so we can take a look? If not, then please take a look at the original viper_wheel.obj file and make sure that vertices and faces are defined properly. You can also do a quick sanity check using demo_MBS_collision_trimesh, replacing the mesh in that demo with your wheel mesh, and see if the visualization and/or collision are done properly. This can help us narrow down the issue as well. 

Thank you,

Luning