Indigo Renderer Forum

Hey Ono,
just coming up again with an old request...

Now maybe even easier to realize since we have some proper alpha rendering mode?!

How is this shadow catcher hack supposed to work again?

+1

Best for photo montage renderings.

It should be a tag or material for a (free to define) ground mesh that only gets "colored" by shadow rays.
Actually its the renderpass "shadows" for that object only or so...

Yip.

OnoSendai wrote:How is this shadow catcher hack supposed to work again?

This would be a full shadow pass mode associated with a shadow material.

If the second eye vertex (first being camera) is not hitting a shadow material -> render white
If this is a shadow material -> render the resulting radiance divided by shadow material albedo.

Etienne

galinette wrote:

OnoSendai wrote:How is this shadow catcher hack supposed to work again?

This would be a full shadow pass mode associated with a shadow material.

If the second eye vertex (first being camera) is not hitting a shadow material -> render white
If this is a shadow material -> render the resulting radiance divided by shadow material albedo.

Etienne

That could work somewhat. Would only really make sense for Lambertian shadow material.
Also I don't know if the workflow is good as you would have to render out a separate shadow pass and composite together.

OnoSendai wrote:That could work somewhat. Would only really make sense for Lambertian shadow material.

Yup, forgot to tell that

OnoSendai wrote:Also I don't know if the workflow is good as you would have to render out a separate shadow pass and composite together.

I thought this was the request. There are other 1-pass solutions with envmaps, but it's very impratical for unbiased renderers.

galinette wrote:

OnoSendai wrote:That could work somewhat. Would only really make sense for Lambertian shadow material.

Yup, forgot to tell that

OnoSendai wrote:Also I don't know if the workflow is good as you would have to render out a separate shadow pass and composite together.

I thought this was the request. There are other 1-pass solutions with envmaps, but it's very impratical for unbiased renderers.

I will try an approach something like this. Basically I will define the 'unshadow fraction' to be something like reflected occluded luminance divided by reflected unoccluded luminance.

teapot under Uffizi probe

It would be great as a pass, for sure.
But it would also help a lot as a shader!
Imagine just placing your model in front of a backplate and assign that shadow material to a floor... ready.
I really would appreciate that option!

zeitmeister wrote:It would be great as a pass, for sure.
But it would also help a lot as a shader!
Imagine just placing your model in front of a backplate and assign that shadow material to a floor... ready.
I really would appreciate that option!

Why did you have to wait until I implement it the other way before you say how you want it? sigh.

OnoSendai wrote:Why did you have to wait until I implement it the other way before you say how you want it? sigh.

Just because you are so fast and nobody expected to see some results within days ^^
Another big benefit would be Background replacement via a HiRez image to be done directly in Indigo for fast composition, without doing 1001 renderings in Indigo and putting stuff together in PS...

Zom-B wrote:

OnoSendai wrote: Another big benefit would be Background replacement via a HiRez image to be done directly in Indigo for fast composition, without doing 1001 renderings in Indigo and putting stuff together in PS...

This can be done with a background plate in the scene directly right?