ies generator

[SgWRX]

hi. i have iesGen4 and like it. i'm wondering if there is a program that would help create a light which is similar to a rectangle spot light that you might find in 3ds max non-photometric lights.

 

as far as i can tell the iesGen4 is basically a "lathed" output 360 degrees.

 

thanks,

[Francisco Penaloza]

and why not use the rectangle spot light from Max??

[SgWRX]

ah, i didn't explain - i'm using iray for a night render. there's a small stone bridge wall over a water feature that we want to light with a type of rectangular light. iray won't recognize non-photometric lights. i did model a plane with self illumination but it's not a sharp edge fall-off. i've played around modeling a narrow box and placing a spotlight inside it, such that the box it sits in creates nice sharp edges but they are too sharp haha. i think the self illum plane seems to get me closest to a rectangle shaped light... it's all so wanky.

[Francisco Penaloza]

You may need to look for a IES profile with that shape.

 

Doing some test here, the best result would be a photometric light in sphere shape with uniform spherical distribution, inside a box with an square opening. simulating the light fixture.

Usually if you model the light fixture as real life and use a photometric light as point shape you should get a pretty close effect to real life, but in your case the hot spot may be too harsh.

Using a sphere seems to work better. You may need to adjust the size to soften or harsh the edges.

Give a try and let us know.

[SgWRX]

[ATTACH=CONFIG]54405[/ATTACH]

 

i had tried a slot through a plane last night and that didn't work, did not think to try a full box with slot in it.

 

this is about a 3ft wide box, 1ft x 1ft high/depth. there's about a 4" slot. in there i put the photometric light.

 

seems to work pretty well, but setting the light to uniform diffuse with a sphere emitting shape of 1" diameter takes about 10,000 iterations before the noise goes away on the walls. if i leave the emitting shape to point, 1,000 iterations will pretty much work with less noise. but i get those hard shadows.

 

i was thinking also of doing some type of glass lens... gotta try that later though.

 

EDIT: oh, i had to set the material on the box to a completely black diffuse A&D, otherwise started to get too much bounced light and hot spots.