Light Issue

[3x3cutor]

Hi there, I am new to Vray, and I just want to ligt a simple scene, i have two lights in opposite directions illumiating a Cylinder. One of the lights has shadows turned on, and the lighting is correct, the other one has shadows turned off, but my lighting is trespassing my object illuminating not only tthe outer part of it, but the interior too!!! and the normals are no even facing that direction. (Light direction that is)

Help me please.... the only solution i have found is turning on the shadows for both lights, but I dont want two different shadows at the same time!!!!

I really need to pull this off!!

Thanks a lot

[green]

Hi 3x3cutor,
The issue you are experiencing is completely normal. Without shadows enabled, light will pass uninterrupted through any objects in your scene (as you can see with your cylinder).

You may be able to sneak around this problem using light linking. Here is a video that explains the process of light linking in Maya:
http://www.digitaltutors.com/11/trai...864&autoplay=1

Now, here's how you should be able to use light linking to solve your problem:
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1. Try taking your problem light, duplicate it, but don't move it. On the duplicate light, enable shadows (this will give you 2 identical lights in the exact same position - one that is casting shadows, and another light which has no shadows).

2. Now take your shadow-casting version of the light, and break it's light link to the ground (so the ground doesn't receive the "shadowed" illumination).

3. Take the non-shadow-casting version of the light, and break it's light links to the cylinder objects (so the cylinders don't get the non-shadowed light passing through them).

If I'm understanding your question correctly, then I believe this will give you the result you are looking for.

Good luck, hope this helps

[3x3cutor]

Hi 3x3cutor,
The issue you are experiencing is completely normal. Without shadows enabled, light will pass uninterrupted through any objects in your scene (as you can see with your cylinder).

You may be able to sneak around this problem using light linking. Here is a video that explains the process of light linking in Maya:
http://www.digitaltutors.com/11/trai...864&autoplay=1

Now, here's how you should be able to use light linking to solve your problem:
-----------------------------------------------------------------------------------------------------------
1. Try taking your problem light, duplicate it, but don't move it. On the duplicate light, enable shadows (this will give you 2 identical lights in the exact same position - one that is casting shadows, and another light which has no shadows).

2. Now take your shadow-casting version of the light, and break it's light link to the ground (so the ground doesn't receive the "shadowed" illumination).

3. Take the non-shadow-casting version of the light, and break it's light links to the cylinder objects (so the cylinders don't get the non-shadowed light passing through them).

If I'm understanding your question correctly, then I believe this will give you the result you are looking for.

Good luck, hope this helps

Hey!!! it worked...but now Im getting this wierd look in only some part of the surface, like this spotty lookg... and the far I place the light source (the one with the "double light rig") it is more apparent

[3x3cutor]

I finally could upload the images, so that would be clearer for you to see what my problem is.... I just want 1 light to be casting shadows but several light sources projecting direct lighting to all my scene.... when I did what you told me, I got the last shown result Thank you very much!!!

[green]

It looks like this could be an issue with your shadow-casting and non-shadow-casting lights occupying the *exact* same space.

My apologies - I realize that this is exactly what I told you to do in the earlier post. I initially tested the above solution using mental ray, which didn't have these shadow artifacts that you are experiencing. Looking at your render, though, it looks like you might be rendering in V-Ray, and when I tested this setup in V-Ray, I was indeed able to reproduce the shadow artifacts that you are getting on the side of your cylinder.

To resolve this problem, try taking the shadow-casting version of your duplicated light, and move it very slightly in front of the non-shadow-casting light.

It seems that when the 2 lights were in the *exact* same spot, the rectangular light plane from the non-shadow-casting light may have been interfering with the shadows from the shadow-casting light, resulting in the shadow artifacts.

[3x3cutor]

Thank you very much green...i'll try that out and let you know how it goes...i also just posted another problem i ran into today about glossy reflections...would you mind taking a peek? Thank you very much for you help, im beginning my rendering learning starting with vray!
Have a great day!

[3x3cutor]

That worked perfectly thanks a lot green