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Floor continuity issue

Posted: 10 Nov 2019, 05:31
by shac12
Hi,

I seem to be having an issue with my scene where the borders between floors seems to be at different heights or for some reason not contiguous. Should any object roll between resizable floor elements the contact points disappear momentarily and then reappear as soon as the object has moved past the border between elements and onto the floor element itself.

I have checked the heights and locations of all the floor elements and they seem to be correct and the same height as each other so I'm not sure what is causing this issue. My scene is included for reference. The file name in question is

UGV_PureWheels_convex_frame1.ttt

https://unsw-my.sharepoint.com/:f:/g/pe ... w?e=ViP0nL

Kind Regards,
Sharif

Re: Floor continuity issue

Posted: 11 Nov 2019, 07:25
by coppelia
Hello Sharif,

the first thing that I notice is that your vehicle is hyperstatic (i.e. there are 4 contact points to the floor, but in theory, and depending on the physics engine, there will and can only be 3 contact points to the floor). Most engines have some compliance and your might not notice that problem, but it could introduce subtle artifacts, where e.g. your vehicle will not roll straight when it should. So I highly recommend to introduce some kind of spring/damper between front and rear wheels.

Your issue with the contact points depends also on the physics engine you are using. For the engine, there are two cuboid borders to pass. I recommend in your situation to create a floor that is made by a single large cuboid.

Cheers

Re: Floor continuity issue

Posted: 01 Feb 2020, 07:24
by shac12
Hi Coppelia,

Could I instead add a spring damper to each 4ws/4wd module ? This would more closely simulate real life as there is a rubber tire between the wheel and the ground.

Kind Regards,
Sharif

Re: Floor continuity issue

Posted: 03 Feb 2020, 14:07
by coppelia
Yes, that is a good idea. Have a look how that was done in the example model in Models/examples/simple Ackermann steering.ttm

Cheers