VrayIES orientation, please check this ies file.

[pailhead]

I am very confused with the vrayies and it's orientation. I must admit that i know nothing about the standard, but i know what i find logical and what not.

This specific produc, the ERCO axis walklight:

http://www.erco.com/products/outdoor...li_downl_1.php

has this ies file:

http://www.erco.com/download/data/_p...klight_392.zip

Judging from the sheets, it should point perpendicular to the fixture's surface in the horizontal plane, and some 60 deg from it in the vertical (30deg to the horizontal plane).

When i put the IES file into vrayIES, it creates a nice rectangular shape, which corresponds to the fixture shape:




But when i place this into the scene the cast is terribly wrong.

Then i tested it with the default photometric light, and it makes (no) sense:




Now I have a bunch of issues that i find confusing:

1. Is this a user-end error, or is there something wrong with the .IES file?
2. Why does the standard photometric light in max have the web distribution icon, and vray does not?
3. If there is one vector defined between the light source point and the lights target point, which other parameter (vector?) defines the web's rotation along this axis?

When i placed the model from the first picture, it cast the light to the left. With "targeted" ticked off, i could rotate the light around the axis, but i couldn't figure immidiately around which one (it seemed logical around the local Z axis).


What is the proper procedure to place a ies file via vrayies, that simply won't work the way it's supposed to?

If i try to place the light at 0,0,0, and the target at 0,0,-1, the light will point towards the X axis, (mainly, it is actually slightly angled towards the ground). I could then turn off targeted, and manually rotate the light, but this really seems like a very long process.....

first i try it with the vrayIES, it can work fine, but it may also fail. Then i have to make a standard light to figure out where it's pointing and by how much i need to rotate it, and then repeat the whole process again with the vrayies.

[pailhead]

I don't question the rocket science behind this thing, i'm pretty sure it makes sense to lighting gurus. I'm just trying to comprehend it as a mere mortal

[pailhead]

Actually i spoke to soon. Now i'm no longer convinced that there is any logic behind this.

Here i aligned the taget with its parent light, and then moved it in -z direction.




And all the time, i want to get this:




Not because i like it, but because thats how it should be judging from the spec sheets and descriptions.

[pailhead]

Please believe me!



This is what gives the proper effect:

[voltron7]

haven't had time to test yet, but that ies file gives my ies viewer an error and won't render a preview...so maybe it's just a bad file??

[pailhead]

No the IES works fine, it just has weird orientation. I realized that all of these erco files should be placed in max the same way - light at 0,0,0 target at 0,0,-1. Any wall mounted fixture will shine in the world x direction, while floor mounted and ceiling mounted will shine in positive and negative Z. The actual light object has the same orientation in all of these examples (0,0,0 pointing at 0,0,-1).

[Roest]

It happens to me very often with ies lights. Really irritating, especially if you finally have the good orientation and you don't like it. Pick another Ies light and you can start all over again

[vlado]

I've made a note to add orientation controls to the IES lights, although you might be able to do the same thing if you rotate the pivot of the light node.

Best regards,
Vlado