Help needed. Render puts slight shadow for transparent rendering

Support Lighting and Rendering
1

Is there way to fix it? I have my plane set to “Shadow catcher” and Film is transparent.
Basically I want only shadows around the object and not around.

Blender 2.93.1. If you need blend file. Let me know, I will upload it.

Thanks in advance :slight_smile:

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2

Basically I want only shadows around the object and not around.

Not too sure what you are asking. Can you make this clearer?

Edit: oh sorry I see now. I wasn’t seeing the borders originally.

I’m not sure what this cause is but you can probably use a curve adjustment on the alpha layer in composite to increase the opacity in the areas

3

Yes sure :slight_smile:

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In other words - Blender generates the dim shadow around main object (in blue). And there are shadows casted by objects (green). The objects itself (red).

So I want render to have only casted shadow, and not surrounding one. That way I can tender objects such that they can be plugged in in to other images without artifacts. :slight_smile:

4

I just edited my original msg

5

I am pretty new to blender. Is there some reference with tutorial how to work with composite?
So I can figure your comment out after studying it. Would appreciate it :slight_smile:

6

Not really off the top of my head because haven’t watched any myself.

You may get something out of this one for the shadow catcher.

1 Like
7

Thanks! I will take a look :slight_smile:

8

Was not able to figure out with compositing. However Seems like I found a solution.

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So in order to have clean surrounding ShadowCatgher object has to have a material (Principled BSDF) with white base color. Roughness to 0 and (in my case) alpha set to 0.5.

And I was able to get clean images and nice shadows :slight_smile:
Even if the radius of a light is quite high

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Just for fun. This is how it looks like if alpha is set to 1.0

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Edit:
Hm… Seems like roughness does no impact appearance of that noise. By the look of it, you can control how soft the shadows (on the edges will be) with roughness of shadow catcher material.

1 Like
9

Thanks for sharing your solution.

I haven’t experience this issue with the shadow catcher yet and I couldn’t replicate regardless of the material settings.