SU 2014 section cut shadow bug

kaas · 3 Apr 2014, 10:34

I just noticed a bug that sometimes happens in SU2014.

Shadow artifacts appear when changing to scenes with a section cut while shadows are on. These scenes only have an 'active selection planes' property. If I rotate the 'bugged' view it seems like the part that's been cut off is ghosted.

Once this happens, the only option is to toggle 'display section cuts' to 'fix' it. I tested the same file in SU2013 and I can't reproduce it there.

I made a simple file to check if was a problem with my current project but I can reproduce it in the simple file (see attachment) as well. Just switch scenes several times and after a few times the ghosted shadows appear, very visible when rotating the view.

sectionShadowArtifacts.skp

Rich O Brien · 3 Apr 2014, 10:39

See it here too

Krisidious · 3 Apr 2014, 10:45

That's ground level isn't it? I can't tell as the file is 14 and I don't have that.

kaas · 3 Apr 2014, 10:54

@krisidious said:

That's ground level isn't it? I can't tell as the file is 14 and I don't have that.

It's not ground level. The ghosted shadows are visible only when there's geometry behind it. With just the background behind the ghost - it's gone.

I can't reproduce it in SU2013 so must be new.

Dave R · 3 Apr 2014, 11:23

I see it too in your model. That is weird.

TIG · 3 Apr 2014, 11:34

I see it too - PC v2014.

The geometry above the section_plane appears to be casting weird shadows on what's visible below it...

However if I purge unused in Model > Statistics the issue stops.

BUT if I only purge the unused Components it does not.

You have three materials called '$Irr Cache', '$Light Sprite' and 'glas'.
If I purge those [now unused] the issue stops, suggesting it related to the materials messing with the SKP's data-base - although 'fix_issues' does nothing !

Very oddly... if leave the unused components in the SKP... but I 'Delete' any one of those three materials from the Materials Browser, that fixes the issue.
Deleting any one of them resolves it - as if something in the Materials data-base is foobar !

A non-destructive solution [in case you want to use the components/materials later on] is to add a new material to the Model with the Material Browser's '+' button - this immediately fixes the phantom-shadow issue [ ], even when that new material is unused - then you can just Delete that unwanted material from the Materials Browser - the fix is not reversed by that. This 'material-add' seems to jolt the Model's Material data-base into normality, which in turn stops the phantom-shadow issue

It is VERY weird !

Dave R · 3 Apr 2014, 11:39

Good catch, TIG. Editing one of the materials in an external editor seems to fix it as well.

kaas · 3 Apr 2014, 12:18

@tig said:

You have three materials called '$Irr Cache', '$Light Sprite' and 'glas'.
If I purge those [now unused] the issue stops, suggesting it related to the materials messing with the SKP's data-base - although 'fix_issues' does nothing !

Very oddly... if leave the unused components in the SKP... but I 'Delete' any one of those three materials from the Materials Browser, that fixes the issue.
Deleting any one of them resolves it - as if something in the Materials data-base is foobar !

A non-destructive solution [in case you want to use the components/materials later on] is to add a new material to the Model with the Material Browser's '+' button - this immediately fixes the phantom-shadow issue [ ], even when that new material is unused - then you can just Delete that unwanted material from the Materials Browser - the fix is not reversed by that. This 'material-add' seems to jolt the Model's Material data-base into normality, which in turn stops the phantom-shadow issue

It is VERY weird !

Thank for your reply TIG. '$Irr Cache', '$Light Sprite' are materials created by LightUp every time I open a file in SketchUp.

I tried your suggestions but they only seem to temporary 'fix' the problem.

Purge all materials so only the default material is left: after a few scene changes, it's back
create a new material. At that moment it's 'fixed' but after a few scene changes it's back.

very strange...indeed.