Octane Area Lights are broken in 31.12

[dmerziii]

I have submitted an official support ticket for this, but wanted to post here in case anyone else has noticed this behavior as well.

In Octane 2025.5 Blender (custom build 30.11) - Octane Area Lights worked as expected between light power/size relationship. However, Octane Area Lights in 2026.5 (Addon build 31.12) there seems to be a bug, you do not get the desired/same result using the same metrics. HOWEVER, it seems to be specifically the Octane Area Light itself, if you build the same light/same node setup, using a Mesh Plane, you will get the same result as in 30.11. Scale, size, everything else is exactly the same.

See screenshots for comparison.

Windows 10, RTX 5090

[dmerziii]

Also tried the latest stable version (released yesterday) 31.13 - and no change on this front, still Octane Area Lights are not respecting power/size relationship.

[linograndiotoy]

I'll check this, thanks.

[dmerziii]

Thanks, Lino

[linograndiotoy]

Everything looks fine on my end.

Area Light:

Plane:

I've also attached the Blender file I used for testing:

Area_VS_Plane1.blend

(133.67 KiB) Downloaded 9 times

I may have misunderstood the issue you're describing, so it would be helpful if you could share a sample scene that reproduces the problem.

Thanks!

[dmerziii]

Thanks for digging into this Lino - I'm going to do some more testing/digging on my end and report back.

[dmerziii]

Okay, here's my follow-up. Hope you don't mind I used claude to help make more technical comparisons and trying to remove my human error.
What your test shows is the area light at 1m by 1m gives an identical output from Area Light to Mesh Plane Light (all other factors being the same).

However, in my tests, I'm getting different results when you deviate away from the physical 1m by 1m size w/ area lights, especially when comparing to 30.11 area lights (blend files for both versions attached) - I have the same size lights (5 total) across both versions here. Things are matching at 1m - but not elsewhere.

I had Claude put together a .pdf (also attached) w/ all the data, hopefully to help illustrate what I'm experiencing.

Octane_AreaLight_30-11_vs_31-13_comparison.pdf

(121.69 KiB) Downloaded 11 times

[dmerziii]

To follow up w/ a quick example from your very own scene, Lino - if you simply change the light size to 0.5 meters - you can see the difference (when scale is applied to 1.0).

Area Light loses power (when output power/illumination should be constant, just changing the shape/highlight/shadow).

See attached screenshots.

[linograndiotoy]

I've run some comparisons with Area (Quad) Lights in Octane Standalone, and I can confirm that there are two size parameters that, in my opinion, should also be exposed in OctaneRender for Blender.

I'll keep you posted!