[feynman]

Hi,

I'm trying to render light fixtures using CITIZEN CL-L103-MC3WW1-C high power LEDs http://ce.citizen.co.jp/lighting_led/en ... index.html which have a 120° output angle at 265 lumen per LED. However, when setting up an emissive material based on lumen, a carefully modelled LED of such type barely lights the interior of the light fixture itself - the real world model proves that this is not so. I've found much information on how to model and render standard LEDs themselves, but nothing regarding the type I'm using; the LED itself renders very well, but there's something wrong with its illumination.

Are there some special issues to consider when lighting a scene with such chip-on-board emitters?

Thank you very much in advance!

[tom]

Are you trapping the emitter behind that 0.5 mm resin?

[feynman]

Tom,

thanks for that quick answer! No, I've applied the emissive material to a two-polygon rectangular surface which is not covered by any other polygons (as the real world thing is). Just typing that, it occurs to me that maybe one should use two surfaces (four polygons) arranged like a vee at a 120° angle? But, still, will that suffice to solve the "dimness" issue?

Cheers.

[tom]

Could you send a screenshot please?

[feynman]

Thanks Tom, replied by pm with links to images...

[tom]

Thanks, saw the images now. So, basically you're complaining about low intensity. But you know, it's not just the emitter lumens affecting the final picture. Are you also matching the camera parameters and the material of fixture?

[feynman]

Thanks Tom,

probably not good enough yet. With such a wealth of adjustment options in Maxwell, it's quite tricky to very quickly obtain, for example, black powdercoated aluminium sheet metal; the reflectivity, the slight orange peel effect of powdercoating, etc.

In any case, your hint sounds like simulating the output of such type of LEDs correctly is manageable in principle - which is encouraging. Back to the materials and camera settings then...

[Half Life]

If you haven't already watched these free videos on the basics of the material system they may help you to gain some better control over the results:

http://think.maxwellrender.com/tutorial ... thor=73948

Best,
Jason.

[tom]

In any case, your hint sounds like simulating the output of such type of LEDs correctly is manageable in principle - which is encouraging. Back to the materials and camera settings then...

Absolutely! Because, adjusting the intensity may look innocent but, it's a tough game.