High Order Bezier Surf Party Trick

[jeff4136]

Based on a previously posted observation and data set
buried deep within a 42 page thread (I think, the forum
search engine can't pinpoint the page searching for
we_be_lite--wf2--.zip so I'll re-post) ...
2008-12-15_142410_we_be_lite--wf2--.zip

_ _ _ _ _ _


I thought this sorta interesting and Bart can confound
and bedazzle his Alias counterparts with it. ;^)


Two settings...
config option intf_out_bezier YES *
change model abs acc to 0.2 inch **
were necessary to get the below attached export of quilt
fid_651 (native degree 3 b-spline surfs).


*It had been my assumption that the config option would
convert degree 3 b-splines to degree 3 beziers, one per
knot span. I see I was mistaken. I'm still wondering
what the developer intended practical purpose is.


** Looser tolerance 'sparces' the surface definition.
Setting the config option and leaving abs acc .001"
results in a busy, poor CV structure U_degree 14,
V_degree 9 bezier export.


2008-12-15_142612_srf_degree_party_trick-iges.zip

 

[jsantangelo]

Has anyone ever dissected the VSSs in the we_be_lite file? Can someone explain the formulas used in the VSS relations of the group THIS_AINT_BAD or where they were derived from? Or was it something Jeff created maybe?

The kd9 is a known dimension (distance between Chain 1 and Chain 2) and as it approaches the end of the origin is approaches zero. So when the kd9 reaches the end, the sd10 evaluates to zero. This allows the VSS to sweep along the entire origin.

<div style="margin-left: 40px; font-style: italic;">sd10 = ((kd9 * .36) + (kd9 * .1* sin(115 * trajpar))) * (1 / .75)
sd11 = 82 + 8 * trajpar
</div>
Just curious

PS - Anybody know what happened to Jeff?

Edited by: jsantangelo