Thin Materials are Transparent

I have modeled cabinets with plastic laminate veneer. The panel substrate is showing through the veneer. I have noticed that in Sketchup if you cover a framework with a sheet material, if the material is less than about 1/4" thick the underlying framework shows through it. I have the material opacity set to 100.

Here’s an example:

Screenshot 2022-07-13 142713

Is this a bug?

Not a bug. It’s a limitation of your graphics card and OpenGL. What you are seeing is called Z-fighting. The various faces are so close together that your graphics card considers them coincident and is unable to determine which should be in front. As you zoom in you will see that the Z-fighting goes away as the distance to the camera reduces.

The usual fix is to tag the object behind the thin one and turn off the visibility for the tag so only the thin object is visible.

See https://www.google.com/url?sa=t&source=web&rct=j&url=https://en.m.wikipedia.org/wiki/Z-fighting&ved=2ahUKEwiJp4eS7vb4AhWFj4kEHRw5DGUQFnoECBEQAQ&usg=AOvVaw2rTiZVEppjWFiAwOKpDb7Y

That almost looks like no thickness? My details have things like air infiltration barriers at 1/32" thickness and I do not get that “z fighting”.

I think it’s a matter of proportion. If the model is only 10’ or so, a thin amount might render ok, but if the model is 100’s of feet like a site model, then it happens more. I think it’s a conscious choice made for the sake of speed of rendering the screen. You can send it to a rendering engine which doesn’t make the error, but it takes a lot more time to sort it out.

If I have anything “Z fighting” in my models, it does show up in Lumion too, so this is not limited to SU.
Here is that same model zoomed out and still no “Z fighting”:

If you’d like to upload the SU file, we can take a look?

Thanks Dave. That makes sense. It only seems to happen at a certain distance to the camera. If I zoom in or out, it goes away.

You’re welcome.

Yes, this is common with Z-fighting. It has to do with the ratio of the distance between faces and the distance between the faces and the camera.

I assume in your case you are adding the laminate in preparation for using OpenCutlist?

You are correct sir.

:+1:

I’m only curious. Does that add enough value to your models to justify the additional work of creating the laminate objects?

It doesn’t create any value to the model itself per se, but if I do not include it then I would have to create a cutlist for that material manually instead of having OpenCutlist optimize and create a cutlist for me. But I am investigating the difference in time it takes to optimize sheet goods manually vs the time it takes to model all those parts.

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