Visualized Normals doesn't scale with viewport

[thomthom]

It appear that normals have a pixel model-space size. Would be nice if they where relative to screen size.

[Aerilius]

A vector has a length and direction. If we want to represent both accurately, need to use model space (and it shows big if close and small if far away).

But often the user is more interested in the direction (especially with normals), and normals have always a very short length which makes this issue a problem.

• Should we show only the direction of vectors, with a screen-space length?
• Should we set a lower length limit to make the arrow recognizable? (This adds a little inconsistency, shorter vectors would not show their real length, longer vectors would do.)
• Can we detect whether a vector is a normal?

[thomthom]

I had not thought of that - vectors in model space.

Internally in SketchUp we have the concept of Unit Vector and Vectors (CUnitVector and CVector3d). But in the Ruby API there is no such distinction.

We do have .unitvector? (http://ruby.sketchup.com/Geom/Vector3d.html#unitvector%3F-instance_method)

This will return true for all vectors with a total length of 1.0. We could use that, drawing unit vectors with fixed size in the viewport. Then for non-unit-vectors one could assume it's in modelspace.

It will have the edge case of whenever you have a model space vector that happen to be length of one it'll be treated as unit vector. But I think that might still cover more of the common uses.

[Aerilius]

Added branch feature-highlight_unitvector

[Aerilius]

Merged branch feature-highlight_unitvector in commit b03116f7004716a39a95c9036f0ddfe5d29c5894