Introduction
In this tutorial you
will learn how to use Lattice Rig to stretch a part of a model.
Part 1: Simple stretching
Generate the lattice
- Open showergel_shape_modify.wire.
This file is located in the CourseWare directory on the Documentation
CD that came with Alias.
- Choose Object Edit > Dynamic Shape Modeling > Lattice Rig to open the Lattice Rig toolbox.
- Select all surfaces of the shower gel
tube model.
- Click Accept Targets to
create the lattice.
Use the lattice to
stretch the model
- In the Lattice Rig toolbox, click on
the Toggle Lattice Engage State tool.
Notice the lattice is now drawn with solid lines,
and the surfaces have a yellow-green highlight.
- Use the and click on the four top
points of the lattice. Notice that they now have arrow manipulators
attached to them.
- Click, using the , and drag any one of the blue arrows
and move the points upwards.
- Release the mouse button. Notice that
the shower gel bottle has stretched proportionally.
This is a simple stretch.
Notice how all parts of the bottle were stretched, including the hook.
In the next part, you will learn how to stretch only part of the
model.
Part 2: Stretch everything
except the hook of the bottle
Sometimes it is important
that parts of your model are preserved when you use Lattice Rig
to modify other parts of the same model. One way to accomplish
this task is to include as Lattice Rig targets only those parts
that should be modified. However, there are times when this isn't
possible. For example, you may need to hold half of the same surface
(or mesh) as you modify another half. This tutorial will show you
how to modify the lattice to achieve this.
Follow the steps in Generate
the lattice of Part 1 of this tutorial to load in the
bottle model and to generate the initial lattice. In this part,
we will modify the initial lattice to include only the part of the
bottle we wish to modify, and then perform the stretch.
Modify the lattice
- Choose Layouts > Front to switch to the side view.
- Using the , draw a pick box around
the bottom points of the lattice to select them. Notice the arrow
manipulators.
- Click and drag the blue arrows
upwards using the . This moves the bottom
of the lattice up. Position the bottom of the lattice just above
the point where the hook meets the bottle.
- Release the mouse button. Notice that
the bottom of the lattice is now drawn in red. This shows that
the Lattice Rig understands that part of your target surfaces are
outside of the lattice. Target geometry outside of the lattice
is never modified (its shape is preserved.)
The parts of the lattice that intersect with
target geometry are locked. When the lattice is engaged, locked
points cannot be moved.
- Engage the lattice by clicking the Toggle
Lattice Engage State tool in the toolbox.
- Using the , draw a pick box around
the top points of the lattice. Notice that the bottom points are
now unselected.
- Using the blue arrow
manipulators attached to the top points, pull the top of the lattice upwards.
Release at the point of your choosing.
- Notice that the part of the shower gel
bottle within the lattice has stretched according to your change
to the lattice, and that the hook outside the lattice retains its
original shape.