PolderAnimation wrote: Fri Aug 28, 2026 8:59 am It I clik on the 'Octane 2027 Roadmap and Beyond ' it says 'You are not authorised to read this forum.'
Is everyone having that? of is it just me?

Same for me.

everdrone wrote: Sat Aug 15, 2026 6:05 pm Finally! Can't wait to try native diffraction grating shaders!
I want to believe that my blog post contributed to the implementation from OSL to native code

But incorrect caustics at Photon Tracing kernel - here

Hello, guys. :)

-To increase photon or diffuse depthes for add new caustics-:
increase photon or diffuse depthes for add new caustics.png


-To increase specular depthes for remove any black area-:
increase specular depthes for remove any black area.png

But IMPORTANT FIRST: To decrease ...

Hello, guys.

If diffraction grating is disabled as "Grating weight: 0.000" for ignore "Light coherence (micrometer): 100.000", zero roughness is failed and roughness color is incorrect at our sunlight source. But yes correct roughness color is almost white.

Best regards.

Hello, guys.

More issue: (normal) Extraordinary IOR delta's values between -0.100 and +0.100 cause disappear the extraordinary refraction as bug.
EDIT: Film extraordinary IOR between same numbers cause disappear the interference.

Best regards.

I see, well, while dispersion has been supported in Octane for a while in some materials, diffraction has not been - until now with the Physical Optics material - which has not got support for retro-reflectivity.
So, there isn't a material in Octane that supports both at the moment. We could look ...

@arnon.marcus: Yeah. Not dispersion, sorry. But yes diffraction in retro-reflectivity? Because I detected the diffraction in retro-reflectivity of blue traffic sign at highway from our sunlight source.

Hello, guys. :)

ISSUE: horizontally rotating extraordinary ray is incorrect while obique rectangular prism material is horizontally rotating (on "Placement" node only).
--> Watch https://youtu.be/cwCIvoWT-0Y and then to 1:37 (look duration bar of youtube) - in real life

birefringence test ...

CaCO3 (Calcium carbonate, Calcite) material at wavelength of 589.3 nm - see -> https://refractiveindex.info/?shelf=main&book=CaCO3&page=Ghosh-o:
-- ordinary ray:
- ior(o)_D: 1.6583
- V(o)_D: 49.87

-- extraordinary ray:
- ior(e)_D: 1.4861
- V(e)_D : 78.4 - But this isn't in this OR version. :roll ...

But... new Physical Optics material, birefringence doesn't have any extraordinary dispersion!? False.