Surface brightness not working?

[v-cube]

Hello Paul,

I made a quick test and I think something might be wrong here...

when I look up the surface brightness use here:

https://docs.otoy.com/Standalone_2_0/?page_id=390

It should distribute the amount of light independant from the surface area. However in this scene there are two surfaces the larger one is 9 times bigger than the smaller one. both have the same material assigned to them, so surface brightness disabled they should emit the same amount of light, right?
The picture shows that the bigger area is producing much more light...

A I missing something or is it a bug?

best
Andreas

[face_off]

I just did a similar test, and got similar results to you. May I suggest saving your scene as ORBX and post this as a bug report to the Octane Standalone 2.24.2 thread so the Otoy devs can take a closer look.

Paul

[formatio]

I think there is nothing wrong here, the smaller emitter is simply to small to light up larger area.

Here is my test:

Surface brightness is disabled.

The bigger one makes even less impact.

[v-cube]

I just did a similar test, and got similar results to you. May I suggest saving your scene as ORBX and post this as a bug report to the Octane Standalone 2.24.2 thread so the Otoy devs can take a closer look.

Paul

Yes, I will do this on monday.

[v-cube]

just redid the test, now I used 2 materials, first one with SB enabled, second one with SB enabled all other parameters are the same. I also attached the 3dm file in case someone would like to experiment with it.
I will also post this together with the orbx file in the 2.24.2 thread.

lichttest.zip

(222.45 KiB) Downloaded 272 times

[roeland]

Those three planes are modelled as being 1 single emitter. They have the same material ID. A single emitter always has a constant brightness.

To get the expected behaviour the three planes must have a separate material ID, i.e. on the mesh node you should have 3 separate material input pins for the 3 planes. That is how Octane can figure out which triangles in a mesh are part of the same emitter. It will still work if the 3 pins are connected to a single material node.

Here is an example set-up:

lightest-2.orbx

(584.99 KiB) Downloaded 259 times

--
Roeland

[v-cube]

Those three planes are modelled as being 1 single emitter. They have the same material ID. A single emitter always has a constant brightness.

To get the expected behaviour the three planes must have a separate material ID, i.e. on the mesh node you should have 3 separate material input pins for the 3 planes. That is how Octane can figure out which triangles in a mesh are part of the same emitter. It will still work if the 3 pins are connected to a single material node.

Here is an example set-up:

lightest-2.orbx

Roeland

Thank you for your explanation Roeland, Is there currently any way to assign material ID within Rhino?

best Andreas