Vray - light travels through material

[tweerk]

Hello,

 

I'm just learning Vray, so this question may be easy or stupid , anyway this is my problem:

 

I try to create a LED-light fixture.

 

I'm using a standard material on the tubular object. In the object there is a lightsource. If I use a Vray Lightmaterial on an object inside this tube, I cannot control the output of the light. If I use a Vraylight inside the tube, the light travels through the material.

 

which kind of light can I use best? Or what am I doing wrong?

 

Thanks!!

 

Chris

[Ricardo Eloy]

First, don't use Standard mats. You have VRayMat for mostly everything (better and faster). Second, trying to light a scene using light mats is not a good idea. It's not a real light, so it will probably produce some undesired effects. Put a real vray light, instead.

[tweerk]

Thx for the reply,

 

I'm using Vray materials now but my problem is still the same.

I'm also trying IES-data in a Vray-light. If I use the light at the end of the tube, I get the 'desired' result. But if I'm using it inside the tube (ex. at half the tube's length), it still shines through the tube/material.

 

Is there some option in the lightsource to change this? Or is there some kind of 2-sided-material option like there is in 3DS?

 

Thx,

 

Chris

[Ricardo Eloy]

All VRay mats are 2-sided by default. Still, placing the light inside the fixture sounds unnecessary... I mean, unless you're using caustics to (try to) get a IES look, there's really no need to do it. Place it outside the lamp, instead.

[tweerk]

Thx, it is indeed what I have done.

 

I've placed the light at the end of the tube and put some IES-data of a 50W-Mr16 halogen spot in it. This did the trick for the 12V Halogen-version of the armature. And for the LED-version I also found some data.

 

It is just a simulation of the light-output. My problem is that the lightsource will be +-5cm inside the tube. The product will be a wall-fixture and the light will than be cut off by the cilinders edges. For the LED-version, in real life, the cilinder will give a very sharp, round-shadow(of the edge) on the wall. This I cannot create.

 

Made my renderings, images weren't bad, had my deadline, so the problem isn't urgent anymore.

 

But if someone has a solution for this...

[Ricardo Eloy]

Post the result you're looking for and what you've done. Let's see what can be changed.

[tweerk]

Sorry for the silence, but finally had some time to make a render of the problem.

 

these are the results:

 

http://users.telenet.be/ludoarnoldedmundohughoson/Light_front.jpg

http://users.telenet.be/ludoarnoldedmundohughoson/light_inside.jpg

 

 

From left to right the used lights are:

 

1. IES-light Mr16-50w / 12V halogen

2. Vray light (planar / intensity: 250 ?!?)

3. 2x Linear Light (to simulate a 'fall-off' / 1ste light: 1200lm/ 2nd:350 lm - Warm colour)

4. 2x Linear Light (to simulate a 'fall-off' / 1ste light: 1200lm/ 2nd:350 lm - Cold colour)

5. IES-light of a LED-panel of 20 conventional LED's

 

In the 1ste image the lights are place at the exit of the tubes.

 

In the 2nd image, I've placed the lights inside the tubes. As you can see, the light travels through the material. In most cases the tubes doesn't 'cut-off' the light. In real life, the lights are placed inside the tube, which generates a more narrow lightbundle.

 

Maybe someone has a solution for this?

 

 

Thx,

 

Chris