Issue with getting shadows from objects with same IDs Tweet

[noisyboyuk]

I initially brought this up in the 3.06 Release thread but I thought I better follow it it up here as the more I look into this it seems as though it might be something done by design (or I'm just being an idiot) and I didn't want to bog down the thread with something that wasn't relevant to the release.

I have a problem with rendering shadows from 2 objects which have the same ID but more specifically it seems to only be a problem when the objects are on top of each other or close enough to cast shadows onto each other. For example in this image, the sphere is on top of a plane and they both have ID number 2 but the shadow pass comes out empty:

However in this attachment, I again have two objects (two spheres) which share the same ID number (ID #2) and this time I have turned off the ID for the plane. This actually does allow me to render shadows for two objects together with the same ID as they are both on top of the plane but still doesn't give me a solution for exporting the plane shadows together with the spheres without a second render:

Finally I used the exact same ID set up as the last image (both spheres set to #2 and no ID for the plane) and put the spheres on top of each other. Notice that the same thing happens as when I put a sphere onto a plane and set both their IDs to the same number. The two spheres don't receive any shadows and the only thing receiving shadows is the plane as it is the only object excluded from the Render Layer selection.

To me it looks as though if a Render Layer is set to cast shadows, that layer is then excluded from receiving shadows. This causes problems if both objects you wish to included in the same ID number are casting shadows onto each other and you want to get both of those objects shadows in a single pass.

I'm sure there is a simple reason for this but is there a way around this at all?

Thanks!

Kraig.

[mojave]

This seems like the expected behavior as the render pass as it works will just generate shadows projected by the current active render layer into objects that do not belong to the same layer.

If both your objects would belong to the same render layer that means that the shadow cast by the top onto the bottom one will be rendered as part of the same layer, hence discarding it. Depending the result you want to achieve you'd need to arrange your layers in a different way.

We're planning to release with the final v3.06 (perhaps even in the next test build) a new shadow pass as a beauty pass, which will generate global shadows, regardless the layer ID.

I hope that helps.

[noisyboyuk]

This seems like the expected behavior as the render pass as it works will just generate shadows projected by the current active render layer into objects that do not belong to the same layer.

If both your objects would belong to the same render layer that means that the shadow cast by the top onto the bottom one will be rendered as part of the same layer, hence discarding it. Depending the result you want to achieve you'd need to arrange your layers in a different way.

We're planning to release with the final v3.06 (perhaps even in the next test build) a new shadow pass as a beauty pass, which will generate global shadows, regardless the layer ID.

I hope that helps.

Awesome, thanks! I believe we spoke about this on the Octane Render Facebook group but it's good to know that this is also the reason for this issue as well.

It isn't the end of the world if it doesn't work as I can either do it in separate passes or just go with Arnold if the update doesn't come in time. I'm just about to go into a job so I'm just trying to streamline the workflow before we get started. I'm basically trying to remove as many steps as possible as the turnaround is going to be insane :p

At least now I know that it isn't currently possible and I shouldn't spend any more time working this out but I look forward to the next release

Thanks again!

Kraig.