Indigo Renderer Forum

Hi,

again and over again this question:
How do I set up a correct IES emitter material in C4D?
My attempt:

- new Indigo material (diffuse)
- color slot: pure white, 0% gain ("Zunahme"?)
- emission slot: blackbody, "Use IES" activated an linked with my preferred IES profile, emission scale activated with 1 and lumen

Is this correct? And to which geometry do I have to attach that material again? To a sphere or cube with low resolution faces? Or to a simple plane?

Maybe someone please could upload a standard IES material to the material database in order to avoid confusion in future?


Thanks in advance!

zeitmeister wrote:And to which geometry do I have to attach that material again? To a sphere or cube with low resolution faces? Or to a simple plane?

This I can tell: a single triangle ! If you apply the material to a mesh each of its triangles will spread light.

That's how I got the base for my avatar, I used a geo sphere (the colors are MLT)

Alright,
and the IES then is only pointing and emitting in normal direction, right? Like all other emitters?

Sure is !

Thanks a lot!

Remains the question about the correct material setup in C4D ...

Hi David,

IES files usually have an emission scaling encoded, only if you wish to override it, you should enable the emission scaling.

The spectrum can be any spectrum.

For best performance the materials albedo (colour) channel should be black.

Cheers!

Thank you, done and saved!

I am getting now a problem with my IES-file:
When previewing the IES material, everything is correct. If I export my scene, I get an error message:

Hi zeitmeister, me again because there's nothing serious an exporter writer can do about this error. It's within Indigo since IES are supported: an IES file must define exactly one lamp, yours has its num_lamps parameter greater than 1.

The other limitation with IES files is that they must be designed to spread light over an hemispherical region, not any more: that's a 90° profile revolved around the vertical axis. The IES reading will fail if the definition goes over 90°.

Oh no!

That means I have to create one specific IES emitter material for every emitter mesh?
This really sucks!
I've got 42 Spotlights in my scene ... do I have to create 42 IES emitter materials?

zeitmeister wrote:Oh no!

That means I have to create one specific IES emitter material for every emitter mesh?
This really sucks!
I've got 42 Spotlights in my scene ... do I have to create 42 IES emitter materials?

No, you can use the same material on every emitter.

What CTZn meant is that Indigo only supports some types of IES data: the ones with exactly one light and less than 90° emission profile (because currently, indigo does not do double sided emission).

When you said the preview was fine, do you mean the IES preview in Cindigo? It is indeed a bit strange that that one worked, but not when used in a proper scene.

Aaaah!

Alright, I got the point!
Plus, I discovered the IES preview button … but it's not available in the C4D material editor; only in the light tag.
Do you think you could fix that? It would be much more comfortable!

I have the exact same problem with lighting an interior.

PLEASE SEE BELOW.....

IT WAS THE IES FILES THAT CAUSED PROBLEMS FOR OUR RENDERINGS, NOT INDIGO.

So test multiple IES files because for some reason some are corrupted.

Thank you.

IES Lighting in visualization software for interior architure is really becoming a big deal.
$100-200 software like Lightup, Twilight, etc are doing a great job with ease of use for obtaining IES lighting effects.
More progressive software like Twinmotion has an easy way to fake real lighting (beam spreads, power, etc)
It would be great if Indigo could somehow make IES easy to use.
I 'm sure there are other still renders out there that make IES easy to use but I like Indigo a lot & have a lot of $ invested in it- multiple license & nodes....
So it would be great to be able to use it for interior lighting with IES files.
( I'm not that interested in the realtime interactive rendering debate but the programs like Lumion, Twinmotion, & other game engine based programs coming on the market should have every still rendering developer thinking about ease of use........without retreating back to the "head in the sand" excuse that our rendered image quality is better the way we do it.)
This rant is brought to you by my frustration with the IES lighting , a topic that seems to be at least 2 years old but still without Step by Step ease of use instructions for us non technical users
Thank you

There is a tutorial on the use of IES lights in the Support/Tutorials section.

I't not particularly in depth and could use an update but It's a start.

Yes I followed the Tutorial & it works for 1 or 2 different IES files but as soon as I add more I get the num_lamp error again.

Well.............................

The problem that I was having with using IES files IS NOT AN INDIGO PROBLEM

After testing, the IES files that I downloaded from Indigo website worked so we unassigned those.

and after changing all of the Ingido IES files to generic General Electric IES files, that represent their PAR lamps,
INDIGO RENDERED PROPERLY THE 1ST TIME.

The interior scene has about 50 total light fixtures using about 6 different IES files

Thanks to those who tried to help!