Rework isoparametric cells demo and linear cell demo

@cory.quammen and @ahernsean I have reworked these Isoparametric cells and Linear cells demos, adding an option to display a single cell. Additionally I have done changes to the font sizes and made more extensive use of maps and dicts which makes it a lot easier to specify initial orientations. It is really useful in the Isoparametric cells case where there are lots of points.

On my test site see:

• IsoparametricCellsDemo
• LinearCellsDemo

The use of the plinth definitely helps when visualising a single cell. Single cell visualisation was useful for selecting a good orientation.

For example, in the case of the QuadraticPyramid, you can really see the asymmetric pyramid:

This one is interesting, there is an isolated point in the centre (point 26), the source code actually mentions this but no reason why:

Wow, the new images convey the point ordering in these cells much better than the previous images!

I like these! My only nitpick would be to request that the plinth be drawn as an opaque slab. Having the plinth be translucent adds unnecessary complexity.

added 1 commit

• 8b385f08 - Using vtkLightKit

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I think that this is the best that I can do. I have used the vtkLightKit, so the lighting is so much better IMHO. These are the first vtkLightKit examples in the vtk-examples!

Changes are:

• Using vtkLightKit
• Colors have been reworked.
• The base has been thinned and the objects float just above the base. @ahernsean I experimented with the opacity of the base and decided to leave it semi-opaque. If it's fully opaque, the view in the +Y direction will show a series of point numbers with no linking lines.
• The yellow spheres are yellow where the part of the sphere is external to the object, if inside the object, the spheres pick up coloring from the internal faces. I think it helps to emphasize the structure a bit better.
• Font sizes have changed a bit.
• I have just used the default settings for vtkLightKit.
• The text and actor properties have been moved into functions.
• Finally, it helps to think of the surfaces as being sheets of glass.

Please compare these images with the previous ones:

Nice job on the lighting. I like this iteration.

I don't understand what "the view in the +Y direction will show a series of point numbers with no linking lines" means, but for now I'll take your word for it that this looks better.

LGTM +1

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• b75b55a5 - Adding an orientation widget

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marked this merge request as ready

mentioned in commit 493f5e52

merged