Some Weird Layout Viewport Color Leaks

I am experiencing a weird viewport color leak. I have attached several screen shots that hopefully will describe what is happening. In summary, I have a pair of stacked viewports for solid lines and dashed lines. When they are sized as I want them to be, the color/material from the backboard “leaks” out from the backboard into what should be empty space [1]. When I stretch these viewports to show more, eventually the leakage stops, and all is shown as it should be [2]. If I change the color/material of the backboard, it makes no difference; it leaks gray. [3] If I use the default color, then everything seems OK; it may be leaking but it doesn’t show [4]. I did the screenshots with the problem viewports active/highlighted.

What is more puzzling is to the left of the problem viewports are two smaller stacked viewports of the same scene but at a different scale; these show none of this leakage that is appearing in the viewports immediately to the right of them.


Difficult to say without the actual LayOut file. Post it if you can. Are the viewports on the same layer? The safest way to control what is on top in LayOut is to use different layers. Then their position on the layers list will determine what covers what.

I will upload the file. The viewports are not on the same layer, and the adjacent viewports are identical but for the scale within and do not show this issue. So, I do not think it is a “what is on top” problem. In fact, there are many, many instances in this file where none of this behavior has surfaced; it is this one pair and the issue goes away when the top border is stretched up far enough.

Oops. I just tried to upload the file and got a “file too large” message. What should I do?

I stripped it down to a minimum. It still seems to be showing the problem.

Norgaard Cabinet STRIPPED.layout (3.3 MB)

Playing with it, I think it might be one of the Vector rendering quirks (read “bugs”) that keep appearing. It disappears if I turn the viewport to use Hybrid or Raster rendering. I wonder if @adam would be the right person to take a look at it.

Personally, I use Vector rendering only when I need to export to DWG. I use High output quality with Raster rendering to export to PDF.

I was using Vector as per suggestions from DaveR to neatly show dashed/hidden lines and features. See “Sketchy Lines Don’t Work in LayOut”. I believe you weighed in on that topic as well.

Regardless, it seems weird that it works fine in all of the other situations, but something triggers this leakage when the top border of the window is down where it is.

I think I will try to move the top border down on the viewport pair to the left and see if that triggers anything.


When I moved the top border of the smaller scale version to the left of the problem pair, guess what? The problem appeared! I attached 2 screenshots with the smaller viewport pair highlighted. Note the maroon leakage in BOTH situations.

Check your styles. It’s printing the assigned layer color.

The style used doesn’t use color by tag. For some obscure reason the face that covers the back side of the opposing face gets hidden when using Vector rendering. One of the reasons why I avoid Vector. Some of the random missing geometry quirks have been fixed in newer LayOut versions, but it still happens.

I’m on my phone so haven’t seen the file. Do the assigned colors to those layers match what you see?

Not necessarily … I changed the material of the backboard to a gray, and the mysterious leak turned gray.

Thanks for exploring!

(PS: I hope none of your homes were in the fire areas, and that everyone is safe. Hopefully, some nice heavy wet snows are there or on their way.)

Yesterday I installed the latest updates to SU and LO. Unfortunately, there was no change.

I had a thought (shocking) : could the leak be caused by a line that is made up of multiple segments, that is, not welded? I am going to weld the lines that define the backboard and see what happens.

Aha. Mystery sorta solved. I edited the portion of the group that was leaking. It was a group created by SectionCutFace. I isolated the “backboard” portion, made it a group, and welded the lines defining the face into one entity (4 edges). I then colored the face. I saved the SU file and opened the LO file.

And, voila, no leakage!

Conclusion: the problem of leakage is not necessarily solved, but an underlying cause of such a bug is perhaps isolated to the defining edges of a shape not being of one piece. Why this would cause a problem and why this would occur only when a viewport is drawn to certain dimensions remains a mystery … to me at least.