#102 raytraces randomly missing pieces of scene

[Karel Kulhavy]

Load the hyperluma.g into mged, set multipane defaults and raytrace in the window with the slanted (non-perpendicular), "overall" view. The lower corner of the scene will be cut off as if masked by some negative body. Shift it a bit and the colours change and the missing piece will be different. BRL-CAD version 7.8.4.

[Karel Kulhavy]

critical .g file

[John Anderson]

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The near corner of the object displayed is being clipped because it is behind the eye point. This happens because of the way that the view is setup in the routine "dgo_autoview". The distance from the view center to the eye is set by choosing the largest of the distances between the view center and the x, y, and z limits of the displayed model. For an oblique view, this can result in clipping of the near corner. Calculating the distance from view center to the eye point as the magnitude of a vector from the displayed model max to the view center will eliminate the clipping, but the object in the default view will then be smaller. I believe the current method is a compromise that works well in most situations, but not in this case.

[Sean Morrison]

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For orthogonal views, the current svn sources were modified so that the eye point will be pulled back outside of the model when z-clipping is turned off. In your (Karel's) case, I bet z-clipping it turned on, though. You can turn z-clipping off with Misc -> Z Clipping on the mged menu. Cheers!