.IES light files-Getting to illuminate correctly

[TomD_Arch]

I am trying to use an .IES file from Philips/Ledalite-TruGroove series. I am not sure if I am missing something about how these files work, so I am hoping someone with full knowledge can help and explain to me.

 

When I install the .IES file and rotate it to align with the direction of the tube (8' long) I would expect the profile to create glow along it's length. It seems to only act as as a spot light, however.

 

I have tried changing the "Shape/Area Shadows" to "Line, Rectangle, and Cylinder" Cylinder just changes the Light Distribution (Type) back to Uniform Spherical. When I use Line and set it's length to 8' nothing seems to happen.

 

What am I not understanding?

[RyderSK]

I think the scenario you depict won't work the way you image it would no matter what you do.

 

IES light profiles, no matter what app, or renderer you use (but I presume Max/Vray), simply map the light gradient pattern to casted light, they won't create the source as well (even though some renderers introduced such concept, I think Arion MaxLive?). You have to use 2 lights.

 

How to do so in Max/Vray for example:

 

Light Source: Either realistic portrayal (hard to sample/long render times)--) Model the light fixture, frosted glass, and apply LightMaterial (for example VrayLightMaterial) to the tubular bulb model)

:Simplification----- ) RectangularLight or LightMaterial mapped to rectangularPlane.

 

Light Pattern: Create IES Lights (IES Photometric or VrayLight for example) and create these only where the light cone would intersect wall or some interesting geometry. Align the light downwards (it simulates the light being cast, so this is the correct axis).

 

You will have to match the intensities of each light source to your liking.

 

3D is Fake. You will always have to think outside of box to force it to behave like you want.

[Ismael]

Are you using v-ray? Anyway, draw a box 8' x 3" and .1" thickness. Apply VrayLight material at .1 intensity...

Use regular Max Photometric light, load the ies and set shadows to vray.

 

[TomD_Arch]

Are you using v-ray? Anyway, draw a box 8' x 3" and .1" thickness. Apply VrayLight material at .1 intensity...

Use regular Max Photometric light, load the ies and set shadows to vray.

 

Ismael: I am using mental ray. The image you are showing captures the exact result I am looking for. I am guessing you are not producing this effect solely with a light loaded with and .ies file??? Did you have to move the location of the .ies object back towards the far wall to get it to show-up there?

[Ismael]

See http://continuingeducation.construction.com/article_print.php?L=223&C=947

 

In about the third photo down you see the same effect as on my back wall.

To make an 8' strip I placed 2 each of 4' ies distribution files from http://www.ledalite.com/resource-centre/downloads?product=879

end to end.

 

And yes, the ies distribution as well as the geometry I created with self illumination go almost from the back wall to the front which I deleted.

I am at work now (Electronics), when I get home I can show you a wire, describe the scene and tell you specifically which ies file I used.

 

If you get the result you want before I get back to you, please let us know so we would not carry on with it.

 

Take care.

[Ismael]

The ies file is the 39S1LAKQxx04.

 

[TomD_Arch]

This is answering a lot of questions for me. Part of the problem is that I was modeling this in a day-lite space and was placing the .ies object above a glass filter in the actual light itself, so the distribution was being obscure by passing through that plane.

 

I am curious about the orientation of the 'Batwing' distribution object. I was under the impression this diagram was a conceptual section of the distribution and would be running the length of the light tube. Looking at your wire frame should those be rotated 90 degrees about the Z axis?

 

P.S.- I really appreciate your taking the time on this!

[Ismael]

IES distributions contain the passing through 'filters' so they do not go inside fixtures. In this case just slightly below. Glad you figured that out.

About rotating, the IES distribution file matches the physical luminaire strip and therefore it is in position. Below I re-did the same scenario with some props and re-rendered with the complete luminaire (including IES) separated from the back wall about the same distance that it is separated each from the side walls:

 

[TomD_Arch]

That is the last key in the puzzle of .ies for me! Thanks Ismael for explaining all of that.