@RaananW I currently use 4.2.1 and was testing 5.4.0 without making any changes to see if it would be a clean transition.
I use var colorData = lineMesh.getVerticesData(VertexBuffer.ColorKind); to get the color array of a line mesh in this case and I update the colors. After the initial render it does not appear that the color data is updating properly in the 5.4.0 version.
The sample in the picture is using my line render mode, this is a gcode viewer. But I am having problems with color changing in other modes as well but it is significantly worse in line render mode.
I couldn’t get quite the same error as my application but I do get a GL_INVALID_OPERATION when applying a StandardMaterial to the mesh and then attempting to do similar logic as my application. In my application I commented out applying the material and the line mesh version of the view looks correct now and is not producing the buffer errors. So something with applying a StandardMaterial to a mesh where you are reading the ColorKind vertex buffer may be a hint into the issue.
I’ll pull down the latest and take a look. I tried making a playground and could not get the same issue to recreate that I am seeing in the gcode viewer so I may be missing something else for the thinInstance version. I use thin instanced cylinders to simulate extrusions and thinInstance is about the only way to make that feasible. Will get back on that later today hopefully.
Then more than likely the solution would be for me to remove the new standard material from the line mesh. If it wasn’t actually being applied in 4 then maybe that’s what is breaking it in 5 in my instance.
Yeah and removing the material from my viewer appears to have resolved the issue for line mesh rendeirng as well. With removing StandardMaterial from linemesh and with the 5.5 update fixing thinInstance I appear to be back in working order again!