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Parallel views issues.

Posted: Wed Apr 17, 2013 5:14 pm
by dvsone1440
Has anyone experienced in parallel views flat single planes (in my case a parking lot) rendering like its broken up into triangles and the triangles alternating colors? Its hard to explain but it looks a lot like what an autocadd pdf will look like of a hatch that is solid. you will see all the individual triangles it used to make the shape with triangles. Even thought it is one singular plane in sketchup (ie if I turn on hidden lines you do not see those triangles.) I can't upload images or I would just post the images. I did do a material id and it looks funny as well.

Re: Parallel views issues.

Posted: Wed Apr 17, 2013 5:22 pm
by JDHill
That sounds like a classic coplanar face situation -- are you certain you are dealing with just one face, and not two, lying in the same plane?

Re: Parallel views issues.

Posted: Wed Apr 17, 2013 5:51 pm
by dvsone1440
that was my first thought. I just double checked to be sure and it is one plane.

Re: Parallel views issues.

Posted: Wed Apr 17, 2013 5:57 pm
by JDHill
In that case, I really can't say what it might be without seeing a model that reproduces the effect (my email is jeremy at nextlimit).

Re: Parallel views issues.

Posted: Wed Apr 17, 2013 10:14 pm
by JDHill
Thanks, you're right, I isolated it to a single face (the blacktop surface) in the model, and it is not a coplanar situation. I cannot say, myself, but it looks like you are just running into floating point limitations arising from the tesselation of the surface (there are extremely long/narrow triangles), and the extremely long lens (over 4000mm using the plugin's parallel view approximation) versus the relatively distant camera position. Zooming in, or switching a top view to perspective and setting fov to 5-15°, the effect disappears -- in real time, if you are rendering in Fire. I'll put together a report for the core developers.

Re: Parallel views issues.

Posted: Thu Apr 18, 2013 1:44 pm
by dvsone1440
Thanks JD. I need to be that far out to capture the entire campus, but certainly nobody would notice if it was a perspective with a really narrow field of view. I will try that thanks.
Derek

Re: Parallel views issues.

Posted: Tue May 12, 2015 6:35 pm
by AgentSix
I am still having this issue in large models. Triangles of discoloration appear throughout large faces. Has a bug report been submitted?

Re: Parallel views issues.

Posted: Tue May 12, 2015 10:05 pm
by JDHill
I've submitted examples, and it has been discussed, but as far as I know, this is a limitation having to do with insufficient floating point precision.