There is a strange effect which happens on some of the surfaces in an exterior tour. The surfaces acts like it’s Z fighting, but even after thoroughly checking SketchUp, the z fighting isn’t the actual issue.
Surprisingly, when the camera moves closer to the surface, the problem disappears and it works as expected. I have observed that such a Z fighting effect appears to be more in FPS camera, as compared to Orbit camera.
Can you please tell me how to solve this problem?
Pls note that the video shared here isn’t my actual scene. But I face the same issue with my own exterior tours.
The issue from the youtube video looks very much like z-fighting. The fact that you see improvement in the orbit mode also points to z-fighting. Orbit mode has camera near plane set to 5cm, while the FPS mode has it set to 1cm. Near plane that is further away helps to reduce z-fighting.
In Shapespark, could you click on the surface that has this issue, set Opacity of the material to 0 to confirm there for sure is no other surface below?
I think if we actually have a Z-fighting issue, it should appear irrespective of the distance. In Sketchup, whenever there is a Z-fighting issue, it keeps showing even when I am too close to the surface, and vice versa. The fact that there is improvement with Orbit camera shows that it’s not a Z-fighting issue and something related to Shapespark rendering of that particular surface.
I happen to check in Sketchup if it’s really a Z-fighting in the modelling, but it’s not. Such errors have also come across many times before, but I did not report them eariler.
I had also done a experiement on this before as following -
Observations -
Such a rendering error occurs for surfaces which has a single face and doesn’t have it extruded/pushed.
It appears when camera distance and the surface is far
Error goes away when camera comes close to the surface.
When switched to orbit camera, visibility of the error reduces even when it’s far (distance-wise)
Experiment -
Increased the width of the error surface by pushing/extruding it by 1feet.
Result - Problem got solved
Increased the distance between error surface and the surface on which it was placed.
Result - Problem reduced.
Re-uploaded the entire model by changing material name of the error surface
Result - Problem solved
So, I strongly believe that this error is caused with something related to Shapespark and not Sketchup.
To clarify, z-fighting problems do not occur only if surfaces are exactly overlapping. Overlapping surface indeed have this problem irrespective of the camera position. Z-fighting occurs also for surfaces that are close to each other. Due to limited precision of a distance representation surfaces that are close to each other start to overlap when viewed from distance. The larger the distance the further away the surfaces need to be to prevent z-fighting. So this problem affects large exterior scenes more than smaller interiors. Please take a look at this article that explains why this happens and why the camera near (different in Orbit mode) affects the issue: Z-fighting - Wikipedia
The best solution is to ensure there are no parallel surfaces that are close to each other in large-scale scenes. You could also increase camera near in a walk mode, but this would cause the camera to see through walls when you walk closely to them.
