Avoiding sunlight falling into section cut opening

Hello :slight_smile:

I’m currently working on a perspective section.
For the perspective I’m working in Sketchup in our 3D model of the building.

I placed a section where I wanted it and added a scene for it, looking straight on. Now here is my problem.

I want the section cut to have visible light and shadow from the sun coming in. But the shadows are not realistic as the sun also is coming in throught the section opening, as if there weren’t walls behind it. It acts as if the section is a big opening.

Is there a way to have to sun only come through the windows?

For example, all those unfurnished rooms should at this point still be completely dark, since they have no windows yet and no other openings.

I would be very grateful for your advice!

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The only way to do that that comes to my mind right now is by creating two different scenes, one with the shadows activated and other without them, then create a masks on layout or use other image manipulation software.

I don’t really get how that would help though? The scene with the activated shadows would still have the wrong shadow

Share the .skp file so we can see what we might be able to do for you.

Right underneath the horizontal section plane cover the building with a transparent png material that lets you look inside the rooms but that blocks sunlight coming in.

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Thank you! I have a drive link because the file is to big to upload here: https://drive.google.com/drive/folders/18xUphiQiHFm-UY3uqyUUfgF-X8cyeDKp?usp=sharing

It is all in German unfortunately but the last scene shows the section cut.

And it is still a work in progress so it’s a bit messy.

The section plane is vertical not horizontal as you can see in the image I attached.

I tried it and light will still fall through the transparent face.

Does this do what you want?

not quite, I want the light to fall in through the window openings

The idea is the same. Replace horizontal with vertical in my answer.

I know, but like I said the transparent surface still lets the sunlight through :frowning:

A transparent png does not let sunlight through.
A transparent jpg does let light through.

a transparent png unfortunately also still lets the light through
a jpeg can’t be transparent I think?

Just use a transparent png. Once again, it blocks sunlight (create shadow). Don’t use a wrong material like transparent jpg which also exist.

I’m on the mobile phone, otherwise I could send you a perfect png material. You could create one in SketchUp though.

Try this.

Uh, it’s here, but it’s transparent!

Before:

After

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I think @RTCool has a good solution. I’m thinking about another option but while working on it, I did my standard cleanup. Fixed incorrect tag usage.


Purged unused.

And merged like materials with CleanUp3. File size reduced by 82% and model isn’t as sluggish.

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I just tested out what @Wo3Dan was suggesting. I knew I had seen it before on the forum, but was at a loss to remember it.

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Oh that is awesome!

I never learned how to use SketchUp correctly it’s just all trial and error and lots of tutorials for me. I also only use it a few times during a semester to make a base vor visualisations or in this case for the first time a section cut.

Tried that immediately and it worked yay! Thank you so much!

Yes, thank you for trying.