How to cast Shadows from invisible objects

Loony

Hi,

for Reallike touch and also for speeding up the rendering (and maybe for lazyness) I like to play with just a HDRI as background, now is the question, what would be the best way to create invisible boxes which cast shadows?

I had the weird effect that my "invisible" plane did cast a shadow, because I used it as light emitter. (did wrote about it in a other topic).

As example; I would use this room:

Source: https://hdrihaven.com/hdri/?c=studio&h=photo_studio_01

And wanna place my char on the bed, how could I make the shadow play that it works somehow good?

Any ideas? I found a Guide at deviantart with Canvas in the rendersettings, but it did not worked for me :(

 

 

Catherine3678ab

Loony said:

Hi,

for Reallike touch and also for speeding up the rendering (and maybe for lazyness) I like to play with just a HDRI as background, now is the question, what would be the best way to create invisible boxes which cast shadows?

I had the weird effect that my "invisible" plane did cast a shadow, because I used it as light emitter. (did wrote about it in a other topic).

As example; I would use this room:

Source: https://hdrihaven.com/hdri/?c=studio&h=photo_studio_01

And wanna place my char on the bed, how could I make the shadow play that it works somehow good?

Any ideas? I found a Guide at deviantart with Canvas in the rendersettings, but it did not worked for me :(

 

Ideas ... a background is a background, it is not part of the foreground, there is nothing to sit on. Your character is 3D, it would need a 3D bed to sit on.

The Dome is like "miles away" ... if draw floor is on, can get shadows on the floor.

DMax

Not 100% sure if this is what you're asking for but this seems like a good product. I am also waiting for it to go on sale.
https://www.daz3d.com/iray-hdri-toolkit

Loony

Catherine3678ab said:

Loony said:

Hi,

for Reallike touch and also for speeding up the rendering (and maybe for lazyness) I like to play with just a HDRI as background, now is the question, what would be the best way to create invisible boxes which cast shadows?

I had the weird effect that my "invisible" plane did cast a shadow, because I used it as light emitter. (did wrote about it in a other topic).

As example; I would use this room:

Source: https://hdrihaven.com/hdri/?c=studio&h=photo_studio_01

And wanna place my char on the bed, how could I make the shadow play that it works somehow good?

Any ideas? I found a Guide at deviantart with Canvas in the rendersettings, but it did not worked for me :(

 

Ideas ... a background is a background, it is not part of the foreground, there is nothing to sit on. Your character is 3D, it would need a 3D bed to sit on.

The Dome is like "miles away" ... if draw floor is on, can get shadows on the floor.

Its possible to play with it.

 

DMax said:

Not 100% sure if this is what you're asking for but this seems like a good product. I am also waiting for it to go on sale.
https://www.daz3d.com/iray-hdri-toolkit

No, thats not what I asked. I asked how to make Invisible Boxes, that let the viewer assume I use the chair in the scene.

Loony

The idea is like this:

This is the base view:

 

Now we place the person on the armchair:

 

And now is the question could we cast invisible shadows from objects to let the viewer think, the person is there on the armchair.

My way was now for this example, to just add the shadows in postwork via Gimp:

 

Leana

You want your character to cast a shadow on the "chair", or the "chair" to cast shadows on something?

In the first case you'd need a shadow catcher.

Loony

@Leana I just updated the Thread :D

I wanna move my 3D chars on the static enviroement in the hdri image, but using invisible boxes to create shadows.

 

Richard Haseltine

In this ase you could use a couple of cylinders for the arms and a cube of plane for the cushion, select them and run Scripts>Utilities>Create Advanced Iray Node Properties, then turn on the Enable Iray Matte option in Parameters and render. Which I am just going to try

Richard Haseltine

So, here's the set-up - I forgot to add make the base colour of the catcher darker, perhaps try to match the colour and other properties of the thing that's taking the  shadows but I just went for black. You might want to use a dForm to flatten ther outside edges of the cylinders to better match the shape of the arms, I was being lazy  (whiich also explains the pose).

Loony

will try that Script thing later, my current rendering is.... slow :(

Not even 1 % :(

Thanks for the example, that looks good! My pose was also just an example, just to show what I wanna say, Like putting an book on a Table, which is part of a HDRI.

 

KA1

Loony said:

will try that Script thing later, my current rendering is.... slow :(

Not even 1 % :(

Thanks for the example, that looks good! My pose was also just an example, just to show what I wanna say, Like putting an book on a Table, which is part of a HDRI.

 

Wow... What are you rendering?? Last time I had anything like that with iRay was on a much older gfx card with a busy scene, heavy atmospheric and dropping to CPU rendering... It took 3 is days!

Loony

I have a strong RTX2070 Super with 8GB, it did take 7 1/2 hours (then i canceld it), it was a 4K image with 1 person and not soo much stuff, but with a wet Skinshell, the wet effect did cause the heavy render...

An alternate camera view in 1440p, did take 3 1/2 hours for the full render.

Normally is a 4K render done in 1-2 Hours, those wet skinshell was maybe the big problem.

Loony

I found now this:

https://www.daz3d.com/iray-hdri-toolkit

That looks pretty much like that what I wanna do :)