Is it possible to hide an object but still display its shadow?


https://forum.reallusion.com/Topic214708.aspx
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By Ibis Fernandez - 10 Years Ago
Been on winter vacation, just came back and am happy to see that ic6 is out!

My first of many questions to come is this....

I would like to have a prop on the stage and light it in a way that it casts a shadow on other props. This is great so far, but is it possible to hide the prop so that only its shadow is displayed. This would be HUGE.

So far any attempts to hide this prop will also hide the shadow Sad
By justaviking - 10 Years Ago
I'm not sure if there is a "correct" option (have an invisible object cast a shadow), but there is a slim chance this trickery might do the job...

What if you have your object out of camera view, located so it casts the shadow where you want it?  You'd need really "sharp" shadow outlines to make up for the distance between the object and where the shadow lands.

Might be worth a try.

Here's a lame sketch, drawn in MSPaint with a mouse...

By mark - 10 Years Ago
I was able to get "real close" by taking the "Opacity" to 1 and the "Shadow Threshold" to 0. You'll have to do that for each Diffusion Map of the avatar...Upper, Lower, etc.

It also might help to take the "Strength" of the Diffusion Map all the way down or delete it all together and depending of the overall lighting of your scene make the Material Settings Diffuse Color black or white. This should work for a prop as well as an avatar which I used.
By Cricky - 10 Years Ago
All Maps turned to Jet Black..except the Mouth Cavity and the Teeth. No Specular, No Bum Maps.. 2 Sided for all.

Only the Shadow knows for sure what lurks there in the darkness of the minds of men. Smile





By Rampa - 10 Years Ago
I wonder if you could do it in two passes that you then mask together. It is possible to export just a mask of the avatar. So if you shoot the scene first with your avatar casting the shadow, then again without the avatar, and a third just rendering the mask, and then using the mask to display the "clean background inside it and the shadowed background outside it.
By rcsinger29 - 10 Years Ago
Not sure if this will work in IC6, but in IC5 if you moved an item "below the floor" it would cast a shadow onto the floor or terrain.
By animagic - 10 Years Ago
This was asked a while ago, which of course challenged some of us to find a solution.

My approach at the time was what Viking is suggesting now: placing the character outside of the camera range.

To make sure that the shadow would be believable, I matched the shadow that was cast be the remote character with the shadow that would have been emitted with the character in place.

This was the setup: the yellow markers indicate the character in place (now hidden).

This was originally done with a drop shadow, but IC6 doesn't have that anymore. However, a self-cast shadow works also, as shown here. The light is a directional light.

Here is the resulting shadow:

The green background is there because of the original request, I believe.

By justaviking - 10 Years Ago
@Animagic,

Wow, that looks just like my sketch (only a lot better, of course).  w00t

You're a genuine wizard.  Thanks!

By animagic - 10 Years Ago
@Viking: YOU did have an idea how to do it that would have worked! That is very encouraging!
By Ibis Fernandez - 10 Years Ago
Those are some great suggestions. I'm still wondering what this self cast shadow thing is, cant quite wrap my head around it. In that example with the green background, it looks like there is an object selected "but invisible" and it's shadow is showing, is that whats going on? If so, how was that done?

Anyhee, basically I accidentally stumbled into what could turn out to be a great way to cel shade characters...



By Rampa - 10 Years Ago
That is looking quite good!

Being that it's a 2D character, does it work to just stack them, and darken the front one a little bit? Or does that come out to sharp?
By justaviking - 10 Years Ago
Ibis,

That was really cool.

Thanks!.

By animagic - 10 Years Ago
Ibis Fernandez (12/30/2014)
Those are some great suggestions. I'm still wondering what this self cast shadow thing is, cant quite wrap my head around it. In that example with the green background, it looks like there is an object selected "but invisible" and it's shadow is showing, is that whats going on? If so, how was that done?

In iClone there used to be different types of shadows. The drop shadow would cast a shadow in space without the necessity of something to cast the shadow on.

In iClone 6, there is only the so-called self-cast shadow, which is the shadow one objects casts on another object. In my original iClone 5 project, I used a drop shadow, which didn't work in iClone 6. So I redid the project with a self-cast shadow.

I was trying to explain my procedure:

  1. I have a character for which I just want the shadow. Let's call her Character A. In my scene this character is situated at the origin and casts a specific shadow.
  2. I place a second identical character (Character B) up and behind the camera, such that the shadow of Character B matches the shadow of Character A. If you look at my first image you see Character B floating in the air. You also see the location of the camera.
  3. Once the shadows of Characters A and B match, you hide Character A. In the image Character A is hidden but selected, hence the yellow outline. This was just to illustrate the location of Character A.

I hope this clarifies what I'm doing. It's easier to do than to describe. What may be best is for me to upload the project file for you to look at. I think that's alright if I just use standard content.

By Ibis Fernandez - 10 Years Ago
Ah! Yeah I understand it now. Thanks man.
By cgi_468384 - 4 Years Ago
I'm also looking for a solution, to hide objects and to cast the real shadows.
In my case I need this for render passes where the shadows of the scene must be the same, regardless if shadow casting objects (in the front) were visible or hidden.
This should be basic feature, it's used in all other softwares.