8

Editable Patch (Patch) 971
A patch sphere with Use True Patch Normals off (left) and
on (right).
Miscellaneous group
Create Sha pe—Creates splines based on the
selected edges. If no edges are selected then splines
arecreatedforallthepatchedges.Thesoftware
promptsyouforaname,typeinanameforthe
shape object and click OK.
Each p atch edge forms an individual spline. Use
this for creating a spline cage based on the patch
edges. This is useful for spline modeling or Surface
tools work.
Patch S mooth—Adjusts the tangent handles of
vertices belonging to selected edges to smooth the
surface of the patch object.
Patch Smooth sets the handles to absolute
positions based on the patch object geometry;
repeated applications have no effect.
Edi ta ble Pa tch (Pat ch)
Selec t an editable patch > Modify panel > Ex pand the
editable patch in the stack display > Patch sub-objec t
level
Select an editable patch > M o dify p anel > Selection
rollout > Patch but ton
Selec t a n editable patch > Right-click the patch > Tools 1
(upper-left) quadrant of the quad menu > Sub-objec ts >
Patch
A patch is an area of a patch object, defined by
threeorfoursurroundingedgesandvertices.
Controls described in this topic let you manipulate
a patch object at the patch level. As well as moving
and rotating patches, you can create a separate
elementbyholdingdowntheSHIFTkeyduringa
move operation. This creates a separate element
of the selected patches.
Tex ture Ma pping Patches: Interpolati on
in Cur ved Space
Patches can now be mapped in curved space; this
means simplified texture mapping for patches. A
planar map on a complex patch object w i ll not be
distorted. At the Patch sub-object level there is a
parameter in the r ight-click quad menu (Tools
1 quadrant) ca lled Linear Mapping. If you leave
Linear Mapping off, then textures are interpolated
in curved space and behave much like texture
mapping a mesh object, predictably.
In the old method, patch mapping is interpolated
between the knot points. This works well with
procedural maps but not so well with bitmaps,
since each p atch is linear in UV space.
A complex patch (on right) no longer deforms a bitmap
The two lef tmost patches show Linear patch
mapping.Thetopleftpatchisapatchwithplanar
mapping and the bottom left shows its UVW
spacerepresentation.Thepatchontherightisa
curved projection where the vectors are used in
UVW space projection. Notice the bottom right