Transcript Surface Continuity

Why is surface modeling important?
 Many products, although they look prismatic, are not.
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Curvature
 Visual difference between curvature vs. tangent connection
of surfaces
Regular Fillet
Curve Continuous Fillet
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Explanation of C0 thru C3
 Surface matching conditions explained
C2
C0 Condition – Surface boundaries share
C3
C1
but no
tangency
Common edge with
curvature
matching
tangency
but
rate ofto
greater
degree
C2 at boundary
curvature
does than
not match
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Advanced Modeling 101
 Importance of visible connection
No “Radii” used; all C2
connection of surfaces
C0 CONDITION
(Contact)
C1 CONDITION
(Tangency)
C2 CONDITION
(Continuity)
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Advanced Modeling 101
 Importance of C2: automotive does not use C1 (Fillets)
because of visible result on high-gloss surfaces.
No “Radii” used; all C2
connection of surfaces
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Advanced Modeling 101
 Bad Curves make bad surfaces
Visible surface change
Profile made up of arc segments
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Advanced Modeling 101
 Good Curves make good surfaces
No visible surface change
Single spline element
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Advanced Modeling 101
Fit Spline Function Tolerance
5 arcs = C1
Fit Spline = C2
Low Tolerance
Fit Spline = C2
Hi Tolerance
Manually Placed
Spline = C2
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Advanced Modeling 101
Curvature Comb – analysis tool to graphically emphasize
rate of curvature
Rate of Curvature Changes
Point of Inflection
Curvature approaches zero
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Advanced Modeling 101
 Display analysis visualization tools
No “Radii” used; all C2
connection of surfaces
OpenGL
Curvature
RealView
Zebra
Face Curves
Section w/ Combs
PhotoWorks
Deviation Analysis
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Why surfacing modeling instead of solid
modeling
 Can not be accomplished in one or a few solid
features
 Radii features will not do; need curve continuous
surface connections
 Needs to look and feel like one contiguous form
Solid modeling approach
verses
Surface Modeling approach
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