Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] I need help! => Topic started by: boomer123 on 2017-08-22, 04:30:08

Title: Render Shadow Only
Post by: boomer123 on 2017-08-22, 04:30:08

Hi, im new to Corona and im trying to figure out to render a shadow only. The Blue Background will be added in photoshop, shadow from it will be from 3dsmax.

The blue background is a cloth texture but i only want to render shadow so i will put the shadow on top of the image on web. I want to render the shadow in 3dsmax to make things more realist than doing it in photoshop.

Thanks!

Title: Re: Render Shadow Only
Post by: boomer123 on 2017-08-22, 04:56:16

Hi All, its all good, managed to figure it out, i assigned a shadow catcher material to the object. Thanks

Title: Re: Render Shadow Only
Post by: boomer123 on 2017-08-22, 09:01:26

Hi Guys, sorry i thought i got it right. Can someone please help me render only the shadow from the same object.

I have Light and Plain, i want to render only the SHADOW from plain based from lights, is it possible?

Thanks

Title: Re: Render Shadow Only
Post by: romullus on 2017-08-22, 10:42:57

You mean like this?

Title: Re: Render Shadow Only
Post by: boomer123 on 2017-08-22, 15:20:48

hi romullus, like that but without the teapot, only the shadow generated by the light to the plane.

Title: Re: Render Shadow Only
Post by: TomG on 2017-08-22, 15:36:32

Quote from: boomer123 on 2017-08-22, 15:20:48

hi romullus, like that but without the teapot, only the shadow generated by the light to the plane.

That's what the render shows though? The teapot is invisible, but the shadow it casts on the plane still shows up.

Title: Re: Render Shadow Only
Post by: boomer123 on 2017-08-23, 01:36:58

Hi Tom, yes but is it possible to export the file as transparent? I only need the actual shadows from the light. How can i export it as transparent? Thanks for your help.

Title: Re: Render Shadow Only
Post by: boomer123 on 2017-08-23, 03:56:18

Hi, managed to figure it out. Thanks for your help guys!

Title: Re: Render Shadow Only
Post by: JEK5019 on 2018-01-17, 11:44:08

hey boomer123.

you mentioned you figured it out - care to share with the group? :)

Title: Re: Render Shadow Only
Post by: flavius22 on 2018-09-26, 10:28:48

Quote from: boomer123 on 2017-08-23, 03:56:18

Hi, managed to figure it out. Thanks for your help guys!

Can you please share how you managed to export only the shadow with transparency? Or can anyone explain how can I do it?

Thank you!

Title: Re: Render Shadow Only
Post by: PROH on 2018-09-26, 13:01:43

Hi.

1 - Set the Shadow Catcher Alpha mode to: For Compositing
2 - Make sure the light is NOT set to be a "Shadowcatcher Illuminator" (if it is, then uncheck it)

Then your wish should be in the VFB alpha channel.

Hope it helps

Title: Re: Render Shadow Only
Post by: flavius22 on 2018-09-27, 09:10:32

Quote from: PROH on 2018-09-26, 13:01:43

Hi.

1 - Set the Shadow Catcher Alpha mode to: For Compositing
2 - Make sure the light is NOT set to be a "Shadowcatcher Illuminator" (if it is, then uncheck it)

Then your wish should be in the VFB alpha channel.

Hope it helps

Thanks for the reply. I only have CoronaSun as a light, I don.t have this option/box there. It's working only with CoronaLight?

Title: Re: Render Shadow Only
Post by: BigAl3D on 2018-11-09, 19:26:31

I'm gonna revive this thread since it's basically my question too. As you can see in the attachment, in the past, I would render out the beauty pass with alpha channel. Then, using C4D's engine, put a plane and a background object with a white material on it, set to compositing background to make it seamless. Also put a Background Object with the same white material set to Composting Background. Then a tag on the car to NOT be seen by Camera, but still cast shadows. The output would be that solid white with just the shadow. In After Effects, I would have to layers with the shadow layers set to Multiply to get my shadow working.

I can't seem to get this same effect with Corona. I've tried Multi-Pass, but I get shadows for EVERYTHING in the scene. Does this workflow exist yet in Corona for C4D?

Title: Re: Render Shadow Only
Post by: BigAl3D on 2018-11-09, 22:39:06

OK so I was able to get a luma mask with only the shadow that I need. Only minor thing is that I just need to invert it in AE and all will be good.

Title: Re: Render Shadow Only
Post by: rubyrieke on 2019-10-01, 01:37:22

What pass did you use to create the luma mask?