when running the rigid tire of demo ChTireTestRig, the slip always zero

[kaidi wang]

Hello,

Thank you so much for providing this wonderful simulator.

I'm new to learn chrono and I have a question.

When I run the rigid tire and the SCM ground test , I tried two methods: fix the slip rate, or set the angular and linear speed under the fixed slip rate by the slip rate formula. However, the output document of the tire longitudinal slip rate was always 0, but the visual interface during the demo running could clearly see that the tire slip rate was not 0, which was abnormal,I don‘t know how to change it.