[HELP] Casting shadows on self-illumination material


#1

Hi guys, so I have a projection scene in 3ds Max, which means all the objects that get projected are set to be self illumination.
I put 2 animated models in the scene and now i want the models to cast shadows on the floor (self illuminated), I can’t find the way to do it. tried to play with vray properties and render a seperate channel like Vray Shadows but I still can’t see the shadows. some ideas?
thanks!


#2

Put a falloff map on the self-illumination slot, and set it to shadow/light, and in the mix curve set 2 points vertical to each other at top and bottom of the curve, and slide them all the way to the left. Assuming I understood what you wanted correctly.


#3

Well I tried it and it didn’t work. Maybe I didn’t explain myself good enough.
I need to render only the shadows of the my characters in the scene, problem is self iiluminating material doesn’t receive shadows, any way I can make him recieve it?


#4

Ok, so I got it correctly. In the self-illumination the map should look like this:

Now that I think about it, adding only one point to the curve and putting it to the top left would also work.

And this what the material looks like with this:

You are not using a raytracer with a GI or multiple lights when you tried it, are you? It might not work if you did.

If you need GI or multiple lights, another idea that might work for you is using matte shadow material on a clone of your self illuminated objects.


#5

I guess my scene in max is the problem, I don’t really know what to do to make the shadows actually visible.
Anyway I tried your trick on another random scene and it worked perfect on the RGB render! only thing I still see only a black scene when I try to look at the VrayShadows channel.
Maybe another problem you can think of? this is my scene btw:

THANK YOU very much man!


#6

Oh, looks like you want to put your 3d models in an image, use vrayMtlWrapper for that:

//youtu.be/zxGjI2elcTc


#7

You will also need reflections if you want to integrate your character in a convincing manner in that scene. (You can render those on black and use anything not black to mask out the existing reflections. Just take care your new reflections aren’t perfectly black. Might be you can solve that also via matte.)
In your scene your reflections seem strangely distorted, though.


#8

I’m on the tutorial right now! thanks alot!!

About the reflection, I didn’t understand it, I’m aware to the fact that I have to put a reflection to make the scene more realistic but I don’t really know how to do it.
I’m trying several ways with no success till now, can you explain what did you mean by using matte to do it please? (as you can see i’m pretty new to this matte/alpha/shadows thing :sad:)

THANKS for your patience guys


#9

I would have to try that myself (and maybe I will, but don’t count on it). Basically the idea is to use a MtlWrapper like mentioned above or the Vray Properties to get an alpha mask for your reflection. Might work, might not work. Rendering the reflections on a black material should work either way, but you would have to find a way to create your own mask based on the rendering (e. g. reserving pure black to be transparent.) Rendering a reflection pass/element might be another approach.
There should also be tutorials for this out there,.


#10

Alright I got you. I will go on and work on it. hopefully i will make it look like I want eventually (short on time because I got load of projects to get done with so my teacher wouldn’t have to transform me into a Vray Shadow XD )

THANKS guys, I appreciate your patience and your will to share your knowledge!
You’re AWESOME!