[deflix]

Im creating an office floor and am modelling the downlighters accurately. What is best practice for the emitters themselves in this instance - clearly cylinders would be way to expensive. Is it good practise to model a frosted tube an put an emitter inside? there will be about 40 of these diffusers in the shot and am keenfor the render to complete sometime this century.

Thanks in advance.

[lebbeus]

I think using cylinders with either an emitter or mxi texture applied would be the best way, though maybe two rectangular planes (one with normals pointing up, the other with normal pointing down) would be less "overhead", ahem

you don't want to be lighting the scene with an emitter inside a frosted material--way too much noise since the scene would be mostly lit via caustics of caustics (if that makes sense)

[m-Que]

Is it good practise to model a frosted tube an put an emitter inside? there will be about 40 of these diffusers in the shot...

You must be kiddnig.
But if you want to give it a try, you can slow down the whole thing even more by using "Full .ior" mode for that frost material, with Dispertion turned on.
Anyway, you're not doing a detailed shot of the lamp, so what you get in the final image will be 40 white stripes of light. So using cylinders with either an emitter or mxi texture applied is definatly the best way. You can also try adding just a little bit of "Lens flare" in the end to make it look more real, if this is what you're after.

[Bubbaloo]

Depending on how much detail will be seen, you can use planes with mxi emitter material applied. That would be even better than a cylinder (less polys).

[deflix]

Presumably for the same reason cited about caustics it is NOT good practise to model glass when rendering an interior space, with bright daylight coming in? just have openings instead?

[zoppo]

old but still valid:

http://www.maxwellrender.com/forum/view ... sc&start=0

[deflix]

zoppo - that is so incredibly useful thanks very much. exactly the information a newcomer like me needs. was never sure how geometry in the scene affected the render, etc... Also this question about pure lambertian.- i had understood that nothing should be 100% in order to actually REDUCE noise.
98% is the recommended limit infact......is that popular knowledge now?

in many ways it seems that the approach is similar to that with lightscape - carefully made single sided-surfaces, clean efficient geometry to achieve noiseless renders. Of course in Lightscape the aim was to reduce artifacts!