Shadow Matte
4798 9 4- Tser
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- protozoan
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As a workaround (for now) you can do the following:
Render a beauty pass of your shadow catcher, and render a beauty unshadowed AOV.
(Then you have basically one with and one without the shadow).
Use for example COPs or another software like Nuke to subtract them from each other.
The result is the shadow.
Render a beauty pass of your shadow catcher, and render a beauty unshadowed AOV.
(Then you have basically one with and one without the shadow).
Use for example COPs or another software like Nuke to subtract them from each other.
The result is the shadow.
Martin Winkler
money man at Alarmstart Germany
money man at Alarmstart Germany
- Mark Wallman
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- ben toogood
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- npetit
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Currently the shadow aov contains both the shadows and reflection occlusion.
The background plate aovs are meant to be composited such as:
Beauty over (plate * invert(shadow) + diffuse + reflection + emission).
The default background shader currently has metallic set to 0 and reflectivity set to 1 with a roughness of 0.3
In order to get diffuse shadows only on the background, dive in the hda and set the principledshadercore reflectivity parm to 0.
We're looking at separating the reflection occlusion into its own pass as well as disabling the glossy reflection aov disabling reflections on the shader. This should help make it more obvious, and a little more straight forward if you are only after diffuse shadows.
The compositing will then be:
Beauty over (plate * invert(shadow + reflection occlusion) + diffuse + reflection + emission).
One of the added benefits of separating the reflection occlusion into its own aov is that it seems to fix an issue with a 100% reflective background currently still letting some of the plate through - this is noticeable when the background shader metallic and reflectivity parms are set to 1, and more obvious still when the roughness is set to 0.
Here is an example COP network showing how to put the passes together with the background shader metallic parm set to 0.4 to make the reflections more obvious.
The background plate aovs are meant to be composited such as:
Beauty over (plate * invert(shadow) + diffuse + reflection + emission).
The default background shader currently has metallic set to 0 and reflectivity set to 1 with a roughness of 0.3
In order to get diffuse shadows only on the background, dive in the hda and set the principledshadercore reflectivity parm to 0.
We're looking at separating the reflection occlusion into its own pass as well as disabling the glossy reflection aov disabling reflections on the shader. This should help make it more obvious, and a little more straight forward if you are only after diffuse shadows.
The compositing will then be:
Beauty over (plate * invert(shadow + reflection occlusion) + diffuse + reflection + emission).
One of the added benefits of separating the reflection occlusion into its own aov is that it seems to fix an issue with a 100% reflective background currently still letting some of the plate through - this is noticeable when the background shader metallic and reflectivity parms are set to 1, and more obvious still when the roughness is set to 0.
Here is an example COP network showing how to put the passes together with the background shader metallic parm set to 0.4 to make the reflections more obvious.
Edited by npetit - 2021年11月25日 00:55:50
- Mark Wallman
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Hi Npetit. This is much better. I know I have a ticket with you. I will try to mock up my examples and send them over to you next week. One thing I should mention is in my custom reflection pass I am outputting direct reflection and indirect reflection. Dome light HDR's show up in the direct and reflections of the characters/objects show up in the indirect. The main one I am using is indirect reflection.
Best
Mark
Best
Mark
Edited by Mark Wallman - 2021年11月25日 05:33:08
- ben toogood
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- dlee
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Hi. This is expected result. "Reflection Occlusion" might be a bit confusing label here... It's actually shadow pass from glossy BSDFs. This certainly *can* be used to generate more traditional-looking reflection occlusion pass (ie ambient occlusion but using glossy BSDF lobe) by using ambient lighting set up (ie a dome light without envmap), but otherwise it will take the current lighting set up into consideration.
So in your particular example, there's just the directional light, and the glossy lobe doesn't line up with the light direction, so no light source is actually being occluded (except for the tail edges of the BSDF lobe due to roughness, but since the light direction for glossy reflection is same as light direction for diffuse, its shadows will resemble that of diffuse lobe's)
So in your particular example, there's just the directional light, and the glossy lobe doesn't line up with the light direction, so no light source is actually being occluded (except for the tail edges of the BSDF lobe due to roughness, but since the light direction for glossy reflection is same as light direction for diffuse, its shadows will resemble that of diffuse lobe's)
- ben toogood
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- OneBigTree
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