LIBGL_ALWAYS_SOFTWARE

[ShuffleWire]

Hello,

Using Webots headless, I'm using xfvs-run. It run fine, but don't use the GPU, and use software library instead. That not a big deal, but it turn out that Lidar data produced by the Software library are different from those generated using a GPU.

Thus, simulation are not behaving the same way using both methods.

One way to improve thing is to start webots using LIBGL_ALWAYS_SOFTWARE=1 webots <additionnal parameters>

It will of course reduce performance, but you end up with simulation behaving much closer that the one executed under xvfs-run

I think it might be useful to add that to the documentation.

[omichel]

Do you observe big differences in the lidar data?
If so, yes, please go ahead and propose an improvement of the documentation.
I believe that more generally, small differences may be observed depending on OpenGL renderer (Software/Mesa, NVIDIA, AMD, Intel, etc.).

[ShuffleWire]

It's not huge, about 10^-7 m (0.001mm) so that might be very well acceptable