Broken lines (graphics) when in "Parallel Projection" + "Front, Back, Right, Left" views

I contacted SketchUp tech support, and after they reveiwed my computer criteria, and checked udated version of SketchUp Pro, they asked me to try different settings under Graphics. I have tried various toggling off and on and mixtures of settings, to no avail.

Broken lines seem to only happen when in Parallel projection and when in “Front” view, etc. The second I rotate model of the four views the lines appear again correctly.

I read a similar issue in a post, and have tried moving a house window forward a little bit, but this doesn’t fix the problem, and even if it did, what time consuming “solution” that would be, to have to move everything forward while in Parallel Projection, and then back again for Perspective viewing. Seems absurd to have to do this.

Please help. Not a computer expert.

I always need to produce building plans for print in 2D (Parallel Projection), but they look very unprofessional with this broken line issue.

using Apple M1 Max.

Also noteworthy is that when sending or importing a Scene to Layout, the broken lines are visible in Layout as well.

Thank you in advance for any help you may have. I am very surprised that SketchUp sent me to a forum, which tells me they aren’t sure of the actual problem.

I uploaded a screenshot, but on my side it shows a texted label, not the actual image, so I hope you can see the image. First time here on a SU forum, not familiar with it at all.



It would help us help you if you share the .skp file.

8" posts.skp (1.1 MB)

Thank you for responding! And so fast! Let me know if the upload worked…

I don’t see any broken lines in your screenshot, only some antialiasing artifacts.
You would get best quality linework from your model by using LayOut to create your documentation, where you can use Vector rendering to get crisp clean lines in your hidden line views.

Thank you for responding, and I apologize if I don’t quite understand. I do use Layout, but the “broken lines” are visible there too. I set Layout for high viewing and exporting in document set up.

Also I’m new to the antialiasing subject and don’t understand it.

Thank you

When viewing the screen shot on my large display, there are broken lines in the windows and also roof trim. Sometimes half of the window will disappear.

The upload worked. I’m not seeing broken lines. I do see the attic window isn’t showing all the edges because you have multiple faces doing the z-fighting thing. I also see some bleeding edges on the roof gables at either side.

The window is easily fixed by tracing edges and deleting the extra faces.

(I also see some exposed reversed faces when switching the face styly to Monochrome.)

In some scenes there is more of the bleed through. Rafters in this view for example.

Turning off the tag for the rafters will fix that.

Other than that I’m not seeing anything unexpected.

I did my usual checks for other things. Some incorrect tag usage.
Screenshot - 6_17_2024 , 12_02_27 PM
Plenty of unused content to purge.
Screenshot - 6_17_2024 , 12_02_45 PM

I wonder if any of the graphics artifacts you are seeing could be due to the model not being at the origin.

Okay thank you again for your time…

Briefly for context: I’ve used SketchUp Pro for many years, but only modeling timber frames. Never had problems because the models were easy and I didn’t need to produce much for visual displays. That has changed now I’m neck deep into drawing house plans for a couple clients. So I’m clearly a beginner as you can see.

  1. My first question is: should I re listen to all of the SU and LO tutorials they have, because I’ve been confused on why I’m getting so many faces. Until you figured out there are too many faces on the attic window, I’ve been really confused and haven’t had the problem before.

I’m also trying to figure out the best strategy for drawing plans, such as windows, because they don’t need to be massed out with the push/pull tool. That’s why they are just a single plane or face.

  1. Forum etiquette? Can I ask my questions or taking too much of your time??? Can you kindly direct me where I can go to deepen my knowledge as a user?

  2. Not sure what Z fighting is, but clearly it’s because of two many faces?

  3. Are bleeding edges something I am doing wrong? Such as the roof trim?

Thank you for the tip on turning tags off in order to reduce or eliminate bleed through, makes perfect sense.

I’m modeling actual plywood thicknesses for the house sheathing, and have been wondering why I see things behind it.

  1. Using Shaded with textures as a style because it’s the closest thing I can find to clean black lines on white background. I Also did find the option for “vector” in Layout, instead of Raster?

  2. Not sure what you mean by model origin? Dummy here.

  3. I’ve had a really hard time drawing anything compound, like a Jack rafter, or roof sheathing, because the dots, or targets don’t seem to align. I zoom in VERY close and can see they’re actually not meeting. So a 3D form doesn’t get created, but rather a broken thing because I can’t figure out why the targets aren’t aligning, when it seems like they are in pencil tool.

Sorry if this is too much, I’m unaware of this forum etiquette, and how to further my ability in these programs. Just a carpenter trying to get good at them.



I build my jack rafters / hips / valleys on the ground as timbers or lumber, then move them into position and trim / adjust / cut as necessary.

For the LayOut issue - have you tried exporting to PDF? The export quality is often far higher (on purpose) than the viewing quality while you are working within LayOut, although reading your previous posts it sounds like some refreshers on the basics of good SketchUp modeling would be helpful.

I don’t suppose it would hurt to go through the tutorials again. If you pick up anything that makes the modeling process easier I would call it time well spent.

Understood. Still, SketchUp is a 3D modeling application and even a simplified 3D window component would probably be better than a 2D version. If you have to create plan sections the 3D model would be more useful than a 2D elevation shape.

Yes. By all means. That’s what this forum is for.

This is a graphics artifact that occurs when two or more faces share the same place in the 3D model space. When the distance between geometry is very small relative to the camera to subject distance you can also get z-fighting. Note how the rafters disappear as you zoom in on the model from that last scene.

No. This is another manifestation of the z-fighting. Hiding edges or turning off tags for objects that aren’t needed anyway will prevent that.

Hidden Line face style with the background set to white will do what you want in that respect.

The place where the red, green, and blue axes cross. Generally it’s best to keep the model close to the origin.

I’m not understanding exactly how you are modeling the jack rafters but you should be able to create the needed geometry. Might help to use some guidelines placed with the Tape Measure tool.

Thank you, yes I’ve tried that too, but I’m pulling the math and layout off the model so it has seemed easier to build jack rafters directly on the model, except that alignment has been hard

yes I will re study all tutorials… and yeah I’ve exported PDFs in high resolution and the broken lines are also in the PDF

Excellent information, very grateful here.

I’ve tried to clean attic window up, until there are no faces on it, just sash lines. So it SEEMS like there is only one face with lines on it. I then temporarily tagged and turned off the other attic window on the other side of the house, so it wouldn’t be layer problem in Parallel Projection and Front. Still getting that broken line look.

How exactly do I trace the faces, and delete extra ones? I’ve been attempting this in edit mode of course, but cannot see that there are too many faces.

I opened the group for editing and used the Line tool to trace the edges. Then I selected faces and deleted them while watching to ensure I didn’t leave any holes. You’d probably find it easier to just make a 3D window object.

okay thanks again!!!

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