Rhino WIP Feature: Elmo. A new Rebuild command for Curves

Serengeti (Rhino WIP)
188

Would it be possible to get a toggle for symmetry?

189

Will the new Rebuild (Elmo) be able to be specified only by Point Count and Degree, or will it also be possible to specify a maximum Deviation? I know thereā€™s a Rebuild Non-Uniform, but perhaps Elmo uses better algorithms and would it be possible to obtain curves that meet the criteria with fewer control points?

190

Another vote for specifying a maximum deviation and allowing the point count to be decided by Elmo - who we know can count - well at least to 5 :wink:

191

the left is an old MFC dialog, I donā€™t think that will change for Rhino 9

The new Rebuild technology doesnā€™t work well with symmetry. It is on the list as:
RH-91839 Rebuild canā€™t create symmetrical curves

I think you could eventually script this, but it will for sure be very slow. It means Rebuild needs to perform a brute force trail and error until it reaches your desired deviation.

192

In the current Rhino WIP rebuild now includes a rebuild to tolerance option.

193

After the latest update, the ā€œDelete Inputā€ command does not delete the curve.

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dfgdfgdfg1703Ɨ901 78.9 KB

194

Yes, seeing that now. As a temp workaround: turn off and back on should make it work

195

I hope Rebuild goes back to being reliable. Today I found it quite frustrating to use, especially since itā€™s something I rely on constantly in my workflow.

196

Can you clarify what that means?

197

I meant that it shouldnā€™t have bugs like this, with settings not working properly. Today I spent the whole time selecting curves just to figure out which one was the new curve and which was the old oneā€”it was quite frustrating. Doing it a couple of times is fine, but if itā€™s a command you use repeatedly while drawing, it becomes a bit of a torture. :downcast_face_with_sweat:

198

@brvdln Iā€™ll send you a newer build that has a fix.

199

Thank you :grinning_face:

This is a great feature & is a very helpful!

It would be super helpful if when you switch to rebuild mode the Max Point Count is set to the current point count & that the tolerance defaults to something other than 0? Maybe 1 unit? At the moment i get a blob on the first run until i make these changes :jack_o_lantern:

I am also seeing some significant lag interacting with the UI (I guess while the engine runs) but the results are excellent :smiley:

I have seen a few examples where nearly co-linear spans could be joined to simplify the output significantly - might that be something that could happen automagically? See blue shapes on the file I have DMā€™d you.

This will be a great addition to Rhino 9, any news on an API in Rhino Common for this functionality?

200

the default (0) actually works as document tolerance, which is currently the minimum value that will be used, but thereā€™s a YT open for that to change it.
RH-94111 Rebuild: to tolerance starts with zero tolerance, unable to get strict tolerances

RH-94339 Rebuild: set max PointCount to current PointCount Value

202

RH-94339 is fixed in Rhino WIP

203

is there a plan to make ā€œelmoā€ accessible somehow in grasshopper?

204

On a similar note, is Elmo accessible via RhinoCommon?

205

Yes, it is currently exposed through

    public static NurbsCurve CreateNurbsCurveFit(Curve curve, Interval domain, 
      NurbsCurveFitParameters rebuildOptions, 
      out Line maximumSeparation, out double thisSeparationParameter, 
      out double nurbsSeparationParameter)

on the Curve class. This may change as we havenā€™t frozen our SDK yet, but in general it will probably be some function on the Curve class.