Ambient occlusion wrong rendering

SketchUp Pro
1

Sketchup renders wrong when turning on ambient occlusion, any ideas?

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image853×668 89.8 KB

2

What is “wrong”? It is hard to tell from the image what you are hoping for. You might want to share the actual SKP file so folks here can explore your model and help find the answer.

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IMG_2751
IMG_27511333×750 208 KB
l

Looks like the framing below is bleeding through.

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4

I wonder if the wood in the benches is PNG based. Some engines I’ve seen in the past, sometimes fail reading PNG alpha values. Maybe Sketchup new engine also fails in doing that.

However it’s also interesting that this is only visible in the shadows area

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5

Without seeing the model it is impossible to say for sure. The effect doesn*t happen with the wood on the lower level. I wonder if the wood slats are in a group that has been given a transparent material while the wood inside has been painted with a wood texture, or vice versa.

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6

Pretty sure this is it. I have a model where I can recreate this and it’s because of a PNG.

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7

I’m was getting the same see through artifacts using Ambient Occlusion within shadows on my stucco walls even though the texture image is a jpg.

Ambient Occlusion ON

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image1691×964 52 KB

Ambient Occlusion OFF

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image1302×695 95.5 KB

In digging a little more into it, I discovered that I accidentally applied a transparent glass material to my main group for this building. So any faces, sub-groups, sub-components inside this main group that had not had a material applied to them already, would have the glass material applied. I did not notice this at first because most of my surface do have materials applied. In my case the back faces of the stucco walls had no initial material and thus were transparent. Once I discovered that, all I had to do was apply the default blank material to the entire group and the strange artifacts within my shadows went away.

Here is a simplified demo showing the behavior:

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8

So my hunch seems to have been right. Seems to be a small bug. Now to invent ways to make use of it…

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9

FYI… Bug ticket has been submitted for this issue :slight_smile:

@ArchyVR Thanks for figuring this out and documenting the problem and the user workaround

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10

Thank you for addressing it and I’m always happy to help make SU and LO better. :slight_smile: