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I keep getting missing polygons or polygons that render black. Anyone know how to get rid of these so the model renders correctly?

I think you need to flip the normals of those polygons -- you are looking at the back faces.

Best,
Jason.

Hi Jason,

I've looked at this but can't find any global setting - does MR rely on having to select each individual polygon then flip it or is there a Render-back-face option or flip-to-camera option? Thanks.

I tried triangle selection and flipping the normals in studio but no dice -- it wants to flip the entire object.

In the Sketchup Plugin in the scene manager, under output you can select "use front or back" for materials and that may clear it up.

Also if you are in Sketchup and all the geometry is in the same context (group, component, etc) you can simply select a face facing the right way and then context click and chose the context menu item "orient faces".

Best,
Jason.

Thanks Jason - appreciated.

If it's not a normal problem, it looks like it might be coplanar faces to me.

+1

Hi Brian,

Prior to exporting from DataCAD and importing into Maxwell, the 3D model viewed and rendered correctly inside our CAD software. I played around with flipping normals in DataCAD as well as Maxwell and have been able to get a better result....it's just fiddly and time consuming.
I've only just begun with MR after moving on from Visual Reality (Renderize Live) which is now very long in the tooth but had a single button that would 'render backface' so irrespective on whether the imported model had flipped normals you could always get a correct render. I was hoping MR had something similar rather than having to locate each individual polygon and reverse its normals.

As far as I know, Maxwell treats it's materials as two sided, so that's why I thought it might be a case of coplanar faces. It could also happen with poor smoothing and unwelded verts. Some CAD programs , although capable of modelling, don't always export the cleanest models.

Hi Brian,

I did uncheck the smoothing option in MR and it improved the look. Thanks again.

Good call Brian -- I was thinking of how Sketchup backface polys don't look right in ZBrush... got a bit confused

Best,
Jason.