Introduction
In this tutorial, you
will learn how to use the Transformer Rig to change the roof of
a car to give it a different centerline.
Part 1: Setting up the
rig by adding targets and constraints
In this part of the tutorial,
you will learn how to set up a rig to modify the roof of the car.
Specifically, you will learn how to associate existing surfaces
of this model as target and constraint surfaces in a rig.
- Open tutorialCar.wire.
This file is located in the CourseWare/wire directory
on the Documentation CD that came with Alias.
- You can see the whole car. All but the
surfaces corresponding to the greenhouse (the roof, the A pillars
and the B pillars) are in the layer named body and
that layer is in Reference state. Click on the square on the right
of the name of the body layer in the layer bar
to make this layer invisible.
We only need to work with the surfaces of the
greenhouse.
- Choose Object Edit > Dynamic Shape Modeling > Transformer Rig to open the Transformer
Rig toolbox.
- Choose Layouts > Top to open the top view at
full size.
- Use the and draw a pick-box around
the middle surfaces as shown in the figure, and click Accept
Targets to select the roof surfaces as target geometry in
the rig.
- Click the Add Constraints tool
in the Transformer Rig toolbox, and select the remaining surfaces
on both sides of the roof. Click Accept Constraints to
add these surfaces as constraints in the rig.
The word Tan means the constraints are all tangential
constraints. The pale green dots that appear inside the target
surfaces are part of the clamp visualization, and the color indicates
that the target surfaces are free to be modified in the current
rig.
In
the Transformer Rig, any existing geometry can be used as modifiers
or constraints. You can also create geometry to use as modifiers
or constraints. You will do so in Part 2 of this tutorial.
- Choose Pick > Object to leave the Transformer
Rig toolbox for now.
The target surfaces are
picked, and they have history. History for Transformer Rig is created
immediately after you have picked the initial set of surfaces as
targets. Whenever you wish to re-enter the Transformer Rig tool
to edit the rig, use Object Edit > Query Edit and click with the on any of the target surfaces.
Part 2: Create a new surface
to use as the modifier
In this part of the tutorial,
you will learn how to create a surface that will be used as a modifier
for the rig you have created in Part 1. You will be shown how to
create a modifier surface customized for the targets in the rig,
and also customized for the modification in mind.
- Choose Curve Edit > Create > Duplicate Curve . Use the and click on the dashed
line in the center of the middle surface of the roof.
You have just duplicated
the centerline of the roof.
- Choose Transform > Move , and using the , drag the curve down to below
the A pillar, as shown in the figure. Leave the curve picked.
- In the main menu, choose Edit > Duplicate > Mirror ❒, to open the option window of the Mirror
Duplicate function.
Make sure XZ is set.
Click Go.
The curve is now duplicated
and the new copy appears above the A and B pillars.
- Use the to click on the bottom curve
so that both curves are picked.
- Choose Layers > New to create a new layer. Name
the layer Curves.
- Assign the two curves to the Curves layer.
- Choose Surfaces > Skin . Click the bottom curve,
then the top curve. A new surface is created.
- Choose Delete > Delete Construction History . Click Yes in
the dialog that warns you about deleting history on active objects.
- Create a new layer, name it Modifiers,
and assign the skin surface to it.
- Choose Object Edit > Query Edit . Click any target surface
of the greenhouse to re-enter the Transformer Rig tool.
The green and red visual
highlights reappear. This indicates that you have returned to editing
the rig that you have set up in Part 1 of this tutorial.
- Choose the Add Free Modifiers tool
from the toolbox, and click on the skin surface to select it.
Click Accept Modifiers to
confirm.
- Click Go. A popup
window may appear to notify you that the Transformer Rig history has
been set up. If so, click OK to continue.
- Choose Pick > Object to leave the Transformer
Rig tool.
Part 3: Change the modifier
Now that we have completed
the set-up of the rig, this part of the tutorial will show you how
to use regular Alias functionality to make changes to the modifier geometry.
Through Transformer Rig history updates, the target geometry (the
roof surfaces) will update accordingly. This shows you the power
of the Transformer Rig — your update to a single simple surface
will update multiple surfaces in unison.
In this case we will
use the Move CVs and Hulls tool, located at the bottom of the modeling
control panel. You are free to use whichever tool you are comfortable
with to change the modifier surface.
- Make the Curves layer
invisible.
- Choose Pick > Object , and use the to pick the modifier surface.
- In the control panel, turn on the CV/Hull option
under Display. Notice that the CVs for the modifier surface are
now displayed.
- Choose Pick > Nothing , followed by Pick > Point Types > CV . Switch to the Side view,
and pick the two topmost CVs. This actually corresponds to two
rows of CVs of the modifier surface.
- Click the Move CVs and Hulls tool.
Under mode, choose SLIDE.
Orange and yellow arrows appear beside the selected
CVs.
- Using the , click one of the yellow
arrows in the modeling window. Drag the mouse towards the left,
and notice the modifier surface becoming "flatter". Continue to
slide the CVs until the leftmost arrow touches the next CV to the
left, as shown here:
- Release the mouse button. Notice that
the target surfaces change according to the change you have made
to the modifier surface.
- To quickly compare your change to the
original shape of the target surfaces, use Object Edit > Query Edit to reenter the tool (see
Part 2), double-click on the Transformer Rig icon in the toolbox
to open the option window, and click on Show All Geometry.
Optionally, turn off Draw Clamp Visualization under
the Visualization section. You should
then see something like this:
The green surfaces are the target surfaces post-modification.
The cyan line is where the modifier is. The dark gray lines are
the templated version of the original target surfaces. You can
see how much you've flattened the surface.