Part
One: Create a Digital Asset
1.
Create a simple Network Select
the beatrice object and press i
to go into it. Here you will find a model of
half of a character's head. Press tab
> mirror, press a
to select the whole model, and RMB-click
to accept. Next press tab > subdivide,
press a to select
the whole model, and RMB-click
to accept.
Mirroring and
subdividing a model in this way is a repetitive task that is perfect
candidate for building a custom tool using the digital asset methadology.
2.
Create a Subnet
In the Network pane, select
the mirror and subdivide operators
and select Ctrl-RMB > Collapse
into subnet. Rename this new tile mirror_subdivide.
All the parts of a digital asset need to be contained within a subnet
in order to make them portable. It is important that the asset be
portable so that it can be re-used and shared with other modelers.
3.
Create a Digital Asset
Select RMB > Create Type
From…. Name the asset mirror_subdivide
and Mirror Subdivide.
Name the OTL Opmodel.otl.
Click Accept.
It is very important for you to use these names because you will
later update this digital asset with an updated file.
Click on the
varkous tabs. Settle on the Parmameter tab.
The next step is to convert the subnet into an operator type.
At this point you name the operator type then store it in an operator
type library, – which is where the term otl comes from.
Lets call this asset, "mirror subdivide" and store it
in the "Opmodel" OTL.
Otls make it possible to manage and distribute digital assets into
your pipeline.
They can be stored locally to enhance your personal work or put
into general distribution to benefit everyone at your facility.
After the library
has been chosen, you are presented with the Operator Type Properties
panel which lets you define a high-level interface using a combination
of channel references, scripts and expressions. These are the controls
that will be made available to the artists who use this tool.
4.
Create a custom parameter
Select the mirror_subdivide
subnet then press i then drag depth parameter to parameter panel.
Press Accept then show the depth control in the Parameter pane.
Press tab and create a new mirror_subdivide next to the other. Delete
it before moving on.
For example we can dive down into the subnet and drag the subdivide
sop’s "depth" parameter to the type properties pane.
When we press accept, the asset is stored and its controls are available
in the mirror/subdivide’s Parameter pane.
If we press the tab key then we find that the custom mirror subdivide
sop is available and can be used for other models and by other modelers.
Part
Two: Update the Digital Asset
1.
Install a new OTL
Install the OPmodeling.otl
library then open the OTL manager panel.
Click on the new library to make it the current definition.
When the digital asset was created and stored in the otl, it was
set up as a reference.
The new tool references the operator type definition found in the
OTL.
If this definition is updated, then the new definition can be used
in its place.
Let’s imagine that we want to take advantage of some new controls
added to the mirror subdivide asset by another TD.
By loading in a new OTL which also contains this tool then by selecting
it in the operator type library manager we can choose this as the
current definition of the tool.
2.
Remove the old definition
MMB on the operator.
RMB > Synchronize.
Show new controls in the parameter pane.
Click on button to show its affect.
At first nothing happens. Houdini will protect your scene so that
new definitions don’t alter your work until you approve.
If we middle-mouse button over the asset then we see that it is
not yet synchronized with the new definition.
We can choose to match the definition from the operator’s
pop-up menu.
The asset is updated and includes all of the functionality of the
original plus some extra controls built in.
When an asset is updated it can new controls, geometry, kinematics,
shaders or anything else.
For instance, you can press the setup button to template the end
of the chain, shade the templated geometry then show the original
model as a wireframe cage.
This sets up a modeling cage similar to hyper-nurbs style workflows
found in other popular modeling applications.
3.
Apply the tool to another model
Zoom out. Toggle on the
display of the body in the network pane. footprint the face.
Tab > Mirror/Subdivide – pick body to get results.
Click display on merge sop for exporting.
Now lets use this tool on another piece of geometry. As the tool
is activated from the tab key, you can see a prompt for selecting
the geometry.
The asset has been designed to display this prompt in the same way
as any other Houdini tool. This ensures that new digital asset tool
are easily accessible to other Houdini artists.
Part
Three: Turntable Digital Asset
This new functionality was
easily introduced into the modeler’s workflow using the strong
referencing capabilities inherent in digital assets. As a digital
asset like this gets shared around a studio, significant productivity
gains will result.
Of course this
asset only contains a couple of nodes with a few controls. Lets
take a look at a more complex example.Imagine the number of steps
that would be needed to take this model and prepare a turntable
animation for daily review.
1.
Create a turntable
Go up to object
level. Press tab and choose turntable.
Select the model then RMB to accept.
Switch to the ??? camera.
Click on the turntable’s help button. Scroll down to show
informaton.
Playback the animation to show the turntable.
This is another perfect place for digital assets to come into play.
Lets go back up to the object level and from the tab menu, access
a turntable tool which is part of the OPmodeling OTL we loaded a
few steps ago.
OTLs can contain many assets to provide a sort of toolset for building
up a workflow.
Once it is place, switch to the turntable camera and use the built-in
HUD sliders to position the model within the dome.
If you don’t know what the various controls do, you can open
the embedded browser and query the turntable tool to read the asset’s
help.
This built-in help makes it easy to share assets across the pipeline.
Press play to preview the results.
Now modelers throughout a studio can quickly setup their work for
review without worrying about cameras and lights and setting keyframes.
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