Shadows only with vray light ?

[mmikee]

I am trying to get shadows only from the vray light. Is this possible ?
I tried excluding objects from illumination only, but no luck.
Any suggestions ?

Regards,
Mike

[DaForce]

That could be tricky, as the vraylight doesnt cast shadows as such it just doesnt cast light in the "shadowed" areas.

I think if it were possible it would only be possible with a standard max light as you have alot more control.

[mmikee]

Thanks for the reply.
I tried using the standard light, omni, but it did not work. It seems to me like it worked with scanline. Ill have to check on that. Ill keep trying.

Regards,
Mike

[kimgar]

dang, i was sure i had done this before with exclude from illumination or something - but then again i might be dreaming.
anyone managed to pull this off?

[Giovanni]

Well, the old good trick was to duplicate your light, then turn shadows off, and set the intensity to the same value as the original, but negative.

The two lights will cancel each other out everywhere, except in the shadows.

It was used to control raytraced shadows intensity. Just adjust the intensity of both lights: the more intense, the darker the shadows.

But you cannot turn off the shadows of a vray light, so you need to use a MAX standard with vray shadows...

regards

gio

[meanadam]

I was just trying the same thing yesterday. It seems you can't do this with vray - vray light or not? I also could get "include" to work.

[mmikee]

Thanks Giovanni. I do remember reading that one time before now
that you mention it. Ill give it a try.

Regards,
Mike

[Candelero]

I couldn't get your idea, what actually should be visiable and what not, but here are some quick (F9)s.

Setup - 1 plane, 2 boxes, RED & GREEN , 1 VRay Light .

- 1 -
Default render looks like this,
Both boxes illuminated and with shadows:


- 2 -
Now the green box is ecluded with option BOTH from the light.
As you can see it renders absolutely BLACK and no shadows as well.


- 3 -
Now the green box is excluded only from illumination.
It renders BLACK , but there is Shadow ON:


- 4 -
Now the green box is excluded only from Shadows.
It renders Green , but there is Shadow OFF:


If that helps somehow !


Best regards,
nikki Candelero

[mmikee]

Thanks Nikki. I guess it would have helped if I had explained what I was trying to do.
I have rendered an interior shot. I used environment light and 1 direct light for the sun. I dont have very good shadow quality, but I love the way the lighting in the scene looks. What I would like to do is use a light source to give me better shadows, but without the illumination. I hope that makes sense.
I also thought that I would try rendering out a shadow pass and comping it in PS. I really like the overall lighting from the environment in this particular shot. I know that I can use Vray lights at the windows (I often do), But in this shot the environment light looks better to me.
Anyway, thanks for the info. If you have any other tips on how to achieve
this effect, please let me know.

Regards,
Mike

[DaForce]

You need to do exactly what Nikki showed you in - 3 -
Setup a vraylight at the window or something to get the nice shadows that you want...then exclude all the object from illumination only.
This will only cast the shadows and they will still be lite by your other lighting.

Good work Nikki, i was looking at that the other day for something else I was doing...completely forgot about those options.
hahaha

[mmikee]

Hey daforce.....I realized that right after I posted....DUH to me !
Ive been pretty goofy lately. Sorry.

Thanks for all the help guys,
Mike

[phildlight]

Ok, I've got a twist on this. I need the shadows only, and no object. I've got a scene where there is an image with real trees, and my model needs to be "woven" into the trees, so I need shadows on the building of the trees. I've started playing with proxies with matte material, but that just crashed, and I don't think it's the right trick either.

SO, I need the shadows only from the trees, but also, no trees. As a last resort, I could render like option (3) above, but it would require a lot of photochopping to get the tree shadows and the black trees out of the shot, no? Thanks.

[instinct]

if you want an object to be invisible, but still cast shadows, simply select it, right-click -> properties (MAX properties, not vray properties!) and uncheck "visible to camera" then it wont be rendered to rgb, but will still cast shadows and still be visible to reflection. if you dont want it to reflect too, just uncheck "visible to reflection"

Regards,
Thorsten

[phildlight]

Perfect! Thanks. Totally missed that.