strange light material issue

[ello]

hi there,

i just found a strange behaviour, i had one mesh which had a light emitting material applied and it was very bright. now i added another mesh which got the same material applied and suddenly the first mesh emitts less light. somehow like the same mass of light is distributed and the sinlge parts have less power

do i need to post images?? is this known

cheers,
ello

[ROUBAL]

It is normal for what I know, and can be fixed by switching the distribution mode. I am not on my workstation, and I have not Octane on this machine, so I can't tell you exactly how to do, but for what I remember I'm almost sure that you can switch to a mode allowing the light to be not dependent of the emitting surface.

I can't remember if it is a button or the distribution cursor...

[Refracty]

You can calculate because it is always the same Watts distributed.

Lets say you have one Sphere with 100 Watts, then you add a second with the same Material so you have to increase it two 200 Watts because each one has 100 Watts.

[kubo]

that's because you have normalize turn on on both emitters, with normalize (If I'd understood it correctly) the power of all lights gets "equalized" in a way. So if what you want it's to get a more "real" additive result turn off normalize, set up the first light and then the second one and so on.

[roeland]

Until beta 2.45 the light intensity was independent of the size of the emitter. In beta 2.46 this changed, you now specify the total power emitted by all objects that have a certain material assigned. There is currently no way to switch this behavior back. So if you add more light bulbs with the same material you need to increase the power accordingly, but if you change the size of the light bulb you don't need to change anything.

The "distribution" pin is used to vary the intensity of the light source dependent on the direction of the emission, and allows you for example to make a spotlight. "normalize" (for blackbody emitters) is used to keep the luminance of the emitted light from a blackbody constant if the temperature varies, instead of making it brighter if the temperature increases.

--
Roeland

[kubo]

nice and clear, thanks

[ello]

thanks for the input