Cycles Normal node nonfunctional under CPU with OSL enabled

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1

I’ve been trying out some OSL-based shading the last couple of days and so have been rendering on my CPU. Tonight I discovered the Normal node doesn’t seem to function when rendering on CPU with OSL enabled. Is this true or am I missing something?

I made a simple material to test this out:

The GPU renders as expected.

1%20GPU%20Renders%20Everything%20as%20Expected
1%20GPU%20Renders%20Everything%20as%20Expected1390×296 63.2 KB

Switching to CPU rendering and now it renders improperly.

2%20CPU%20Render%20doesn't%20work%20properly
2%20CPU%20Render%20doesn't%20work%20properly1383×300 58 KB

Checking the Fresnel node to make sure that wasn’t the problem. It works fine.

3%20Fresnel%20Works%20under%20CPU%20so%20the%20Problem%20must%20be%20the%20Normal%20node
3%20Fresnel%20Works%20under%20CPU%20so%20the%20Problem%20must%20be%20the%20Normal%20node1384×292 78.6 KB

I don’t normally render on the CPU, so please let me know if I’m doing something wrong. If not, then the Normal node seems bugged.

EDIT:
I turned off OSL and now it renders properly on the CPU. Is there a way around this issue? I was hoping to control some rim lighting with the Normal node using a few OSL nodes in the mix.

4%20Turned%20Off%20OSL%20and%20it%20Works
4%20Turned%20Off%20OSL%20and%20it%20Works1384×302 63.8 KB

EDIT 2:
I see this is a known bug. Anyone know any workarounds? Normal and vector calculations aren’t my thing.

2

OSL is CPU only.
You need an OSL script node pointing at an OSL shader to employ OSL rendering.

An example:

The OSL node has been renamed fresnel_interference and will look different depending on the OSL shader file in the text field. Youtube a tutorial or try the manual.

3

The latest Blender nightly build fixed the bugged Normal node behavior, but is extremely unstable. I didn’t even consider looking for OSL fresnel scripts. Thank you for the suggestion.