9

Patch 991
Pa tch
Example of a patch m odel
A patch is a type of deformable object. A
patch object is useful for creat ing gent ly curved
surfaces, and provides very detailed control for
manipulating complex geometry.
When you apply an Edit Patch modifier (page
1–638) to an object or conv ert it to an editable
patch (page 1–968) object, the software con verts
the object’s geometry into a collection of separate
Bezier patches. E ach patch is made up of three
or four vertices connected by edges, defining a
surface. Patches also have interior vertices that you
can con trol, or let the software control for you.
Yo u c o n t r o l a p a t c h s u r f a c e’ s s h a p e b y
manipulating the ver tices and edges. The surface
is the renderable geometry of the object.
Pa tch-B a s ed Ob j ects
Objects made from patches. Physique (page
2–1076) can work with meshes, patches, NURBS,
splines, and FFD space warps.
Pa th
A path is the line (or other shape) along which
shapes are lofted to create 3D Loft objects (page
1–352).
The Path constraint (page 2–398) also lets you
assignalineorothershapeasamotion path.A
motion path is a form of trajector y (page 3–1025).
Get Path (Lofting)
A circle is lofted along a path to construct a tubular shape. Get
Path chooses the path spline
Yo u u s e G e t P a t h a s a l o f t c r e a t i o n m e t h o d w h e n
you want the path to move to the location of the
selected shape. For example, you use this method
if you have created a shape at the exact location
where you want the base of your loft object to be.
You use Get Path to create a loft at that location.
Get Path causes the path shape to move and rotate
to align itself with t he first shap e on the path:
• The first vertex on the path is located at the first
shape’s pivot point.
• The tangent to the first vertex on the pa th is
aligned with t he positive Z axis of the first
shape.
• T he lo cal Z axis of the p ath is aligned with the
local Y axis of the first shape.
•Thelocalcoordinatesystemoftheresulting
loft object equals the local coordinate system of
the path af ter it has been aligned with the first
shape.
Sometimes, alig ning the tangent of the path with
thepositiveZaxisofthefirstshapedoesnot