viewport normals bug in 2014

[chris_l_waller]

I'm getting an intermittent problem in the viewport in 2014; sometimes when selecting models the normals/tangents flip out. Deselecting the object, it will sometimes flip back to looking correct.

Anyone else notice this?

[chris_l_waller]

just want to bump this up - more and more folks at work are noticing this happening. Any AD folks willing to check it out?

[Steve_Curley]

System specs? Screenshots? Example scene? I'm afraid that just saying "the normals/tangents flip out" doesn't really give us enough to go on.

[chris_l_waller]

Apologies, but I didn't want to write up a lot of stuff if there was no real activity.  Since there seems to be some, I shall enrich the info most willingly.

This is on various intel machines, I5 and I7 cpus, all with 16GB ram, video cards, Nvidia. I will gather a more concrete repro next week.

It is happening in 3dsmax 2014 SP5.  The viewport is set to legacy direct 3d.  Both custom directx shaders and the built in 3ds max hardware display exhibit the problem.

Intermittently, while working, objects as a whole will seem to flip tangent/bitangent.  The normals appear to turn inside out in these cases and fiddling around sometimes flips the model back (selecting, deselecting the mesh, or converting to different mesh types etc.)

I'm now going to see what happens in nitrous dx9 and nitrous dx11.  We might be able to move to one of the other modes if it works more robustly.

I'm setting up a scene and once I get a good repro I will pop it up here for deliberation.

Thanks!  😄

[Steve_Curley]

I doubt very much the actual normals are flipping - the graphics displaying them incorrectly is much more likely.
What graphics card is it, and have you updated the drivers for it?

[chris_l_waller]

The normals are not flipping, it looks very much like the tangent or bitangent data is inconsistent - either flipping or containing errors.

The drivers are up to date.  There are various cards, but amd r9 280x is in my box at work.  All other 3d apps including in game editors and tools work fine with the graphics drivers installed.

I've switched to nitrous dx11, and nitrous dx9, seems to work as expected, which is interesting.  I'll make my test shader work with nitrous dx9 and see if that improves things.