OSL and Displacement problem

Coding OSL Tests and Support
1

I found an issue with enabling OSL rendering mode and using regular displacement.
The scene and materials were made without OSL in mind at first, but recently I decided to do couple parts with OSL shading. The issue is that the displacement with OSL support turned on looks completly broken. I don’t know if this is expected, or my scene got corrupted, or it’s a bug. The issue is present in 3 different releases: official 2.83, 2.90 June 01 (hash: 1d4bae856690) and 2.90 June 07 (hash: 281319653e5b).

Without OSL (correct displacement):

TEST_032
TEST_0321293×840 1.9 MB

With OSL:
TEST_031
TEST_0311293×840 1.92 MB

The shader you see utilise AO, pointiness, slope and elevation to mask and mix different textures.
OSL it’s not used in this shader, but in another object that is in the scene.

Thanks in advance for any help.

2

Ok. After quick investigation I’ve found the culprit and it’s the Musgrave texture.

So basically if OSL is enabled, texture Detail is over 15 and you crank up Lacunarity over 3.780 this is happening:

2020-06-08-20;07;49
2020-06-08-20;07;491300×1118 291 KB

With higher Lacunarity the texture is slowly going all black with small amount of white dots. That’s what’s happening with the displacement on my first post.
If OSL is off, everything is OK.

EDIT: It’s a confirmed bug.