Lines and shapes appearing behind surfaces

So many questions…

I’ve been having this problem where lines that I am placing on certain surfaces are appearing behind the surface itself. Why is this? How can I fix it?

Thank you,

1 Like

Upload your model for a more exact diagnosis. From the screen shot it looks like the lines you are making are not on the surfaces, they are behind them in some places and so appear that way because they are.

There are other problems like open gl bleed through and clipping and back edge styles but I don’t think this looks like those. Drag and drop your file from your hard drive into a response window to find out what’s going on.

1 Like

You might also show an example of what you are trying to build. This isn’t coming out like real construction, where elements seem to be floating in and out of a surface, though it’s clearly an advanced building design. Grouping sections of the facade might help. Working with curved surfaces, all elements need to share the the same planes. Work with this in “show hidden geometry mode”.

Although it is common to break up faces with edges, actually drawing in 2d on a 3d surface, sometimes elements need to be given some real world 3d treatment, thickness etc. to make sense of what we are modeling and how it goes together.

1 Like

1250 Rene-Levesque Sketchup Draft.skp (3.2 MB)

Here is the model! I’ve found a way to make it work but it is very inconsistent. Any idea what the problem is?


How to know whether things are in the same plane or not? Essentially, how would I fix this issue?

Thank you very much.

The front of your building is curved. When you draw new arcs you need to exactly follow the same curve. Starting from scratch it isn’t always easy to duplicate an existing curve in 3D. For that your best bet might be to move-copy an existing curve vertically.

You showed examples of the problem in your first image, but they don’t seem to be present in the skp you shared. Is that because the file you shared is the one where you found a workaround?

1 Like

I can’t open your file because I use an older version (and apparently it doesn’t present the problem anyway). Here is a simple example. With hidden geometry you can see the faces in the pink stripe fit with the faces in the main curved surface. The blue stripe was created with a different number of faces and can’t fit with the main face. The pink stripe was in fact created with geometry copied from the main face and moved to keep aligned with it.

1 Like

Start with an existing arc. Select it and use the move tool, press the option key once to get copy/move and move a fresh version of that arc upward in the Z direction. You can rely on inferencing to stay on plane or tap the up arrow to lock travel to the Z axis. This works with edges or collections of edges. Tap the H key to toggle hidden geometry witch can help you see the invisible facets of the existing arcs.

This model is all one big shell of all raw geometry, nothing has been separated into Components or Groups. This is a very limiting workflow which makes future changes and editing very difficult. You should really look into making each piece of your model separate using components as you go.