Surfacing question

IF he has a program to modify the knotpoints AND has the capability to do the API programming .... the parent surface should be a second degree one. But I think there can be many surface patches all of degree 2 that would be exact. Nothing other than degree 2 woud be IMHO. Those patches could be modified ... and as they are of degree 2 (in theory) the surface would be modified only as far as the second (IIRC) knot point from the one that's changed. So any deformation would be quite local.

GE's TRUCE solids modeler was used (among other things) for a very similar purpose in die design for some stamped airfoils (among other things) IIRC. TRUCE is/was limited to cubics but that's just as good as NURBS of degree 12 for most applications ... you just need more patches at times. And cubics computed faster than NURBS above degree 3.

Make prototype die, make part, use CMM on part (springback & deformation related issues in Titanium alloys), use CMM data to update die model, recut a little, back to the CMM ...... I think they became "predictive" thus reducing the iterations of the cycle.

BTW, TRUCE was GE corporate R&D's development. It was to be the solids engine for Calma but was not sold with the rest of Calma to Computervision, perhaps because it was in development at the time of the sale or perhaps because CV was developing their own.

NOTE: Information this post is based on was released via GE "flyer" (among other public sources) at one time so it is not confidential.

Reply to
Cliff Huprich
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Jerry,

How are you getting the topo mapped errors back into Solidworks? Also, the suggestion that splines are more accurate drive curves in SW it true. Any surfacing geometry is goning to be much much cleaner when based on splines. Give me a call if you still need some help with this.

clay

916.687.7784
Reply to
clay

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