Inconsistencies w/ coplanar planes, face colors, import into Layou

I’m currently developing my preferred techniques to show demo, existing-to-remain, and new walls and how to bring them into layout sheets. I like to have layers set up for all 3 types of partitions and then create scenes that will correspond to the sheets in my drawing sets.

I cut sections above the ground plane and set my section cut lines to be thicker.

I notice that there is an inconsistency in how the bottom faces of my wall volumes (which are coplanar with the top face of my floor volume) are displayed in orthographic projection. In same cases I see the back face of the bottom side of the wall volume (blue) but in other walls in the same model, I see white, which I assume is the top face of the top side of the floor. When I orbit slightly out of orthographic, then at the bottom of the walls where white appeared, I will see the blue.

This is a bummer because I had hit on what I thought was a good solution to visually indicate new vs. existing partitions in my proposed plans: reverse the faces of the bottom of the existing walls from blue to white. The bottoms of the new partitions would be visible as blue and when I print my sheets out to grayscale PDFs, they will appear as gray = new partitions.

Is this not possible? I notice a post by an expert SU person who uses the term “z-fighting”. Does SU have problems dealing with stuff that’s co-planar?

I believe all openGL programs have an issue with co-planer faces…

I think you need two sections planes a slightly different height, with the existing higher…


Thanks for the feedback, John. But would it help to have 2 section planes at different heights? what difference would that make if the issue is the coplanar faces you’re seeing at the bottom of the volumes?

One thought I had is to just pull up the bottom face of the wall volumes a small dimension (say 1"), but I hesitate to go down that road for fear of what repercussions it might have…

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