Modelling / rendering oddity - any ideas?

Hi all

I experienced a strange oddity when exporting my model to a 3rd party program for rendering. Some of my objects in SU had the “Translucent Glass” material applied to the reverse face. On import into the 3rd part app, those objects had unnecessary reflections which could not be removed.

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I noticed that all the objects that had this glass material applied to the reverse face had all been scaled using the SU “Scale” tool. Initially I re-modelled all the affected objects, then I replaced the translucent glass material. Both options worked in solving the unnecessary reflection problem.

However, here’s my question. I have in the past, by mistake, applied materials to the reverse faces. It happens. I find it odd that I would make that mistake on many multiple, different and unrelated objects. Each is in it’s own component and I did not use the same root object to scale and create a “new” component. (So I didn’t use a kitchen cabinet object to create a steel I-beam, I modeled the beam separately from scratch). Is there some bug in SU that automatically applies the “Translucent Glass” material to reverse faces when an object is scaled using the “Scale” tool? Is there an easy way where I could have mistakenly applied a texture to the reverse face of multiple components simultaneously?

If you have a variety of components/groups and you have applied materials directly to their faces and then you apply a material to the group/components that material will be applied to the back faces.
So, in essence I would guess that at some stage in the modelling process you have accidentally used the transparent glass material on a variety of groups/components. This could even be done by grouping several components and painting that group, nothing would appear to change, but if you looked you would find that the back faces had changed.
Here’s a simple example of what I’m trying to say.
Back faces
There are tools to remove materials from groups and components that will leave the other materials untouched.

Thanks @Box Assuming each of those cubes were there own component and did not exist within a parent component, then one would have to mistakenly paint each box by mistake to achieve the same end results (reverse face painted), correct?

Or have accidentally selected them all and clicked with the bucket.

Gosh, so I possibly selected several components, without noting (very strange). Thanks.

It’s possible.
But without a camera looking over your shoulder we can’t be sure.
It may have happened some other way but that is my best guess, pilot error rather than bug.

Note too that by default, the Paint Bucket tool applies transparent materials to both sides of a face. Probably to avoid windows being see-through only in one direction. Some rendering apps require that “glass” parts have two opposing faces for transparency and reflections to work correctly.

The Plugin Material tools can help with this… I rendered an entire pre-fab building catalog for client (print and web) and the tool was invaluable not just for cleaning up the materials, but also for my general workflow.