Your environment does not work in the same way in Rhino 6 evaluation as shown on your screenshot above. I don’t have Rhino 5 with the VSR plug-in to show the rainbow coloured “Light lines” that it has, but I do remember how great they performed when I was working with Rhino 5 about a decade ago. They were exceptionally useful for manipulating of control points with the “Move UVN” tool.
There are a few videos on YouTube that show the VSR “Light lines”. Check the rainbow lines after the 43rd second in the first video
One problem of VSR’s approach was that it used the global mesh setting as a base for the calculation of the geometry, so it was quite heavy to use since the models had to consist multiple times more polygons than the default setting in Rhino. Also, “Light lines” worked on all geometry, unlike Rhino’s native Zebra or curvature analysis that used a custom mesh setting and could include or exclude objects at any time.
Note that the 1st video above with the coloured lines allowed to have a custom number of stripes, hence the change in their thickness. In my opinion, coloured lines are much more usable for evaluation the flow of a surface, because they let the modeler to follow a certain colour along the length of the entire model. This is far less distracting than the regular Zebra stripes.
Also, these colours are like the rainbow, so they allow to easily see the surface control points and the dashed control polygon. On the other hand, the regular black and white Zebra makes these elements less visible (which may be a good thing for evaluation, but less good for checking the control polygon or picking of individual control points).
What I liked a lot in VSR is that it had the coloured lines and the zebra in the same tool, so it’s easy to switch between both at any given moment.
It would be nice if Rhino could have similar quick switch between the Zebra and the Curvature analysis. Currently, they are separate analysis tools that require individual selection of objects every time upon switching to the other type of analysis.
Its a 1-to-1 port from ICEM Surf. I’m not promoting to use zebras of any kind for continuity analysis, but using a numerical or deviation graph for this. Rhino 7 indeed offers a tool for that now.
The problem with Zebras for c.a., it very often requires to have a high resolution render mesh to get a correct feedback, and from time to time you miss something. G2 in Zebras means the zebras have tangent alignment, but how do you judge this?
From my experience I can tell that having a true mathematical G2 continuity is not always the best way to achieve smooth looking reflections on a series of adjacent surfaces. In many cases G1 or G1,5 (something less than a true G2) delivers a better flow and reflections.
I have seen many videos with Alias modeling of cars where the surface continuity is true G2 yet the flow and reflections are distorted. This is why sometimes it’s necessary to check the surface quality with static and dynamic Zebra analysis to help to improve the overall flow. Ideal G2 “on paper” does not mean you get ideal reflections.
It’s a model made for a customer and I can’t send any part of it.
But I can tell you that I used “Blend surface” to make it, followed by “Rebuild surface” to reduce the control points. Then I did some manual control point adjustment with “Move UVN”. Then I applied “Match surface” with G1, because G2 produced some unwanted distortion along the borders. Lastly, I used “Move UVN” again to adjust the 3rd row of control points along the normal direction (the N slider) to achieve nearly G2 continuity.
I think that it would be great if you guys post update videos on the official YouTube channel showing the new features in Rhino 9 WIP. Many users don’t have access to this version and can’t see the improvements. Very few people actually visit the forum’s WIP section and notice these text updates. YouTube has a much broader audience.
They were exceptionally useful for manipulating of control points with the “Move UVN” tool.
