The USD COMP loads and imports most geometric schemas from a USD file in crate/binary or ASCII file formats with extensions as (
.usdc), and (
.usdz). Currently the USD version 0.18.9 is being used in USD COMP. You can drag-drop a USD file into a TouchDesigner network, or import it via the USD File parameter. See also File Types.
The assets from the USD file are saved into a "
.tdc" file with the same name as the USD file inside the TDImportCache folder, which is created next to your toe file. Assets are read from the "
.tdc" file using Import Select OPs (Import Select TOP / Import Select SOP / Import Select CHOP). Upon reloading a
.toe file, the assets can be imported directly from the "
.tdc" cache, and the USD file will not need to be re-imported. However, if there is no existing "
.tdc" (for instance, if the toe file changed computers) then the USD file will be reopened to grab the assets and a new "
.tdc" will be saved out.
To open a USD file in an USD COMP:
1) Specify a valid file path in the "USD File" parameter, including the name of the file with correct .usd extension.
2) This step is varied depending on whether the USD COMP is just created and if any changes in the default values of parameters are required or not. If the file is being loaded for the first time in the network and the default parameter values are accepted then simply press the "Build Network" to generate the USD network and import the assets. Note that we recommend toggling the "Merge Geometry" for any medium or large files as it can significantly improve performance. Generally, any changes in the parameters above the "Build Network" requires the network to be built again.
3) The "Reload" button is being used for reloading the internal assets (e.g. meshes, points, etc.) and this is specifically useful if the file has moved to another location and when the
.toe file is opened the assets were not found and reloaded properly.
4) The "Update" button is used when some changes on USD file are made and we want to merge those changes into the current network without fully rebuilding it.
Here are some examples: https://developer.apple.com/augmented-reality/quick-look/
Parameters - USD Page
file - The path to the USD file. The file can be a binary (.usd or .usdc) or ASCII format (.usda).
reload - A pulse to reload the assets from the file without making any changes to the existing network.
usematerial - A toggle to specify whether the material/shading be enabled for all the geometry primitives with material binding or not. By turning this toggle on, the MAT nodes and -according to the need- the ImportSelect TOPs for texture mapping assets are generated.
cameras - A toggle to specify whether the Camera nodes (subject to be defined in the USD file) created for the USD COMP or not.
Generate Actor COMPs
genactors - When enabled, will generate Actor COMPs in place of Geometry COMPs as the parents' of Import Select SOPs.
mergegeo - A toggle to merge the mergeable geometries SOPs and their transformation COMPs up to a specified merge level. This feature can noticeably increase the performance of the USD COMP network.
mergelevel - Defines the desired merge level for merging the nodes. The start value is 1 which is the root of the network and it increases for the children of nodes the same as their positions within tree hierarchy. By default, this parameter is disabled and can be enabled once the toggle for Merge Geometry is set to ON.
Max Wired Children
maxwiredchildren - This value is used to define how many wired children a Geometry/Null COMP node can have on the same network level (note that this network level refers to all the nodes that can be seen on the same canvas network). If a node has more children than this value, all its children will be relocated inside of it. This is used to prune out the wired children nodes of a parent node to make a lighter and cleaner network. The default value is 5.
computenormals - A toggle for generating normal vectors from subdivision schema specified from USD file using OpenSubdiv library. Turning this toggle to OFF makes will make the SOPs use the TouchDesigner generated normal instead (only CPU mode).
Direct to GPU
gpudirect - A toggle to load the geometry directly to the GPU. This makes the rendering much faster than CPU mode. However, currently the only supported geometries are mesh and point primitives. If a USD scene contains other prim types such as NURBs Patches, an error will be generated for each Import Select SOP that is not supported.
buildnetwork - Every time (including the first time) you specify a new file, or change any parameter from the USD page, you need to re-build it, so it generates the network according to the current selected parameters.
keepparams - A toggle to keep the parameters of the current network over parameters of the re-imported (via Update parameter) network.
keepconnections - A toggle to keep the connection of the current network over the connections of the re-imported (via Update parameter) network.
update - Updates the network. This option is specifically useful when the USD file is edited after the USD network is imported in TouchDesigner.
callbacks - The Callbacks DAT will execute during import or update allowing for modification and customization of the imported operators and resulting network.
Parameters - Play Page
This page includes the animation controls parameters of USD within TouchDesigner.
Shift Animation Start
shiftanimationstart - A toggle to specify whether to shift the animation to the start of animation indicated in the USD file.
Sample Rate Mode
sampleratemode - ⊞ - A menu to choose between the file FPS or custom sample rate.
- File FPS
filefps- uses the FPS from what is defined in the USD file.
custom- uses a desired value specified by Sample Rate parameter.
samplerate - It is used to specify the sample rate (FPS) for the animation. This parameter is disabled by default and can be enabled once the Custom option is selected from the Sample Rate Menu.
playmode - ⊞ - A menu to specify the method used to play the animation.
- Locked to Timeline
lockedtotimeline- This mode locks the animation position to the timeline. The parameters Play, Speed, Index, Cue and Cue Point, are disabled in this mode since the timeline is directly tied to animation position.
- Specify Index
specifyindex- This mode allows the user to specify a particular index (position) in the animation using the Index parameter below. Use this mode for random access to any location in the animation.
sequential- This mode continually plays regardless of the timeline position (the Index parameter is disabled). Play, Speed, Cue, and Cue Point parameters below are enabled to allow some control. The default is set to this value.
initialize - Resets the animation to its initial state.
start - Resets the animation to its initial state and starts playback.
cue - A toggle to jump to Cue Point when it’s set to ON and it stays at that position. Only available when Play Mode is Sequential.
cuepulse - When pressed the animation jumps to the Cue Point and continues from that point.
cuepoint - Set any index in the animation as a point to jump to.
Cue Point Unit
cuepointunit - ⊞ - Specifies a unit type for Cue Point. Changing this will convert the previous unit to the selected unit.
play - A toggle that makes the animation to play when it sets to ON. This Parameter is only available/enabled if the Sequential mode is selected from the Play Mode.
index - This parameter explicitly sets the animation position when Play Mode is set to Specify Index. The units’ menu on the right lets you specify the index in the following units: Index, Frames, Seconds, and Fraction (percentage).
indexunit - ⊞ - Specifies a unit type for Index. Changing this will convert the previous unit to the selected unit.
speed - This is a speed multiplier which only works when Play Mode is Sequential. A value of 1 is the default playback speed. A value of 2 is double speed, 0.5 is half speed and so on.
trim - A toggle to enable the Trim Start and Trim End parameters.
tstart - Sets an in point from the beginning of the animation, allowing you to trim the starting index of the animation. The units’ menu on the right let you specify this position by index, frames, seconds, or fraction (percentage).
Trim Start Unit
tstartunit - ⊞ - Specifies a unit type for Trim Start. Changing this will convert the previous unit to the selected unit.
tend - Sets an end point from the end of the movie, allowing you to trim the ending index of the animation. The units’ menu on the right let you specify this position by index, frames, seconds, or fraction (percentage).
Trim End Unit
tendunit - ⊞ - Specifies a unit type for Trim End. Changing this will convert the previous unit to the selected unit.
textendleft - ⊞ - Determines how USD COMP handles animation positions that lie before the Trim Start position. For example, if Trim Start is set to 1, and the animation current index is -10, the Extend Left menu determines how the animation position is calculated.
textendright - ⊞ - Determines how USD COMP handles animation positions that lie after the Trim End position. For example, if Trim End is set to 20, and the animation current index is 25, the Extend Right menu determines how the animation position is calculated.
Parameters - Xform Page
The Xform parameter page controls the object component's transform in world space.
xord - ⊞ - The menu attached to this parameter allows you to specify the order in which the changes to your Component will take place. Changing the Transform order will change where things go much the same way as going a block and turning east gets you to a different place than turning east and then going a block. In matrix math terms, if we use the 'multiply vector on the right' (column vector) convention, a transform order of Scale, Rotate, Translate would be written as
T * R * S * Position.
- Scale Rotate Translate
- Scale Translate Rotate
- Rotate Scale Translate
- Rotate Translate Scale
- Translate Scale Rotate
- Translate Rotate Scale
rord - ⊞ - The rotational matrix presented when you click on this option allows you to set the transform order for the Component's rotations. As with transform order (above), changing the order in which the Component's rotations take place will alter the Component's final position. A Rotation order of Rx Ry Rz would create the final rotation matrix as follows
R = Rz * Ry * Rx
- Rx Ry Rz
R = Rz * Ry * Rx
- Rx Rz Ry
R = Ry * Rz * Rx
- Ry Rx Rz
R = Rz * Rx * Ry
- Ry Rz Rx
R = Rx * Rz * Ry
- Rz Rx Ry
R = Ry * Rx * Rz
- Rz Ry Rx
R = Rx * Ry * Rz
t - ⊞ - The three fields allow you to specify the amount of movement along any of the three axes; the amount, in degrees, of rotation around any of the three axes; and a non-uniform scaling along the three axes. As an alternative to entering the values directly into these fields, you can modify the values by manipulating the Component in the Viewport with the Select & Transform state.
r - ⊞ - The three fields allow you to specify the amount of movement along any of the three axes; the amount, in degrees, of rotation around any of the three axes; and a non-uniform scaling along the three axes. As an alternative to entering the values directly into these fields, you can modify the values by manipulating the Component in the Viewport with the Select & Transform state.
s - ⊞ - The three fields allow you to specify the amount of movement along any of the three axes; the amount, in degrees, of rotation around any of the three axes; and a non-uniform scaling along the three axes. As an alternative to entering the values directly into these fields, you can modify the values by manipulating the Component in the Viewport with the Select & Transform state.
p - ⊞ - The Pivot point edit fields allow you to define the point about which a Component scales and rotates. Altering the pivot point of a Component produces different results depending on the transformation performed on the Component.
For example, during a scaling operation, if the pivot point of an Component is located at
-1, -1, 0 and you wanted to scale the Component by
0.5 (reduce its size by 50%), the Component would scale toward the pivot point and appear to slide down and to the left.
In the example above, rotations performed on an Component with different pivot points produce very different results.
scale - This field allows you to change the size of an Component uniformly along the three axes.
Note: Scaling a camera's channels is not generally recommended. However, should you decide to do so, the rendered output will match the Viewport as closely as possible when scales are involved.
constrain - Allows the location of the object to be constrained to any other object whose path is specified in this parameter.
lookat - Allows you to orient your Component by naming the Component you would like it to Look At, or point to. Once you have designated this Component to look at, it will continue to face that Component, even if you move it. This is useful if, for instance, you want a camera to follow another Component's movements. The Look At parameter points the Component in question at the other Component's origin.
Tip: To designate a center of interest for the camera that doesn't appear in your scene, create a Null Component and disable its display flag. Then Parent the Camera to the newly created Null Component, and tell the camera to look at this Component using the Look At parameter. You can direct the attention of the camera by moving the Null Component with the Select state. If you want to see both the camera and the Null Component, enable the Null Component's display flag, and use the Select state in an additional Viewport by clicking one of the icons in the top-right corner of the TouchDesigner window.
Look At Up Vector
lookup - ⊞ - When specifying a Look At, it is possible to specify an up vector for the lookat. Without using an up vector, it is possible to get poor animation when the lookat Component passes through the Y axis of the target Component.
- Don't Use Up Vector - Use this option if the look at Component does not pass through the Y axis of the target Component.
- Use Up Vector - This precisely defines the rotates on the Component doing the looking. The Up Vector specified should not be parallel to the look at direction. See Up Vector below.
- Use Quaternions - Quaternions are a mathematical representation of a 3D rotation. This method finds the most efficient means of moving from one point to another on a sphere.
- Don't use up vector
- Use up vector
- Use quaternions
pathsop - Names the SOP that functions as the path you want this Component to move along. For instance, you can name an SOP that provides a spline path for the camera to follow.
Production Tip: For Smooth Motion Along a Path - Having a Component follow an animation path is simple. However, when using a NURBS curve as your path, you might notice that the Component speeds up and slows down unexpectedly as it travels along the path. This is usually because the CVs are spaced unevenly. In such a case, use the Resample SOP to redistribute the CVs so that they are evenly spaced along the curve. A caution however - using a Resample SOP can be slow if you have an animating path curve.
An alternative method is to append a Basis SOP to the path curve and change it to a
Uniform Curve. This way, your Component will move uniformly down the curve, and there is no need for the Resample SOP and the unnecessary points it generates.
roll - Using the angle control you can specify a Component's rotation as it animates along the path.
pos - This parameter lets you specify the Position of the Component along the path. The values you can enter for this parameter range from
0 equals the starting point and
1 equals the end point of the path. The value slider allows for values as high as
10 for multiple "passes" along the path.
Orient along Path
pathorient - If this option is selected, the Component will be oriented along the path. The positive Z axis of the Component will be pointing down the path.
Orient Up Vector
up - ⊞ - When orienting a Component, the Up Vector is used to determine where the positive Y axis points.
bank - The Auto-Bank Factor rolls the Component based on the curvature of the path at its current position. To turn off auto-banking, set the bank scale to
Parameters - Pre-Xform Page
The Pre-Xform parameter page applies a transform to the object component before the Xform page's parameters are applied. That is, it is the same as connecting a Null COMP as a parent of this node, and putting same transform parameters in there as you would in the Pre-Xform page. In terms of matrix math, if we use the 'multiply vector on the right' (column vector) convention, the equation would be
preXForm * xform * vector.
pxform - Enables the transformation on this page.
pxord - ⊞ - Refer to the documentation on Xform page for more information.
- Scale Rotate Translate
- Scale Translate Rotate
- Rotate Scale Translate
- Rotate Translate Scale
- Translate Scale Rotate
- Translate Rotate Scale
prord - ⊞ - Refer to the documentation on Xform page for more information.
- Rx Ry Rz
- Rx Rz Ry
- Ry Rx Rz
- Ry Rz Rx
- Rz Rx Ry
- Rz Ry Rx
pt - ⊞ - Refer to the documentation on Xform page for more information.
pr - ⊞ - Refer to the documentation on Xform page for more information.
ps - ⊞ - Refer to the documentation on Xform page for more information.
pp - ⊞ - Refer to the documentation on Xform page for more information.
pscale - Refer to the documentation on Xform page for more information.
preset - This button will reset this page's transform so it has no translate/rotate/scale.
Commit to Main Transform
pcommit - This button will copy the transform from this page to the main Xform page, and reset this page's transform.
xformmatrixop - This parameter can be used to transform using a 4x4 matrix directly. For information on ways to specify a matrix directly, refer to the Matrix Parameters page.
Parameters - Render Page
material - Selects a MAT to apply to the geometry inside.
drawpriority - Determines the order in which the Components are drawn. Smaller values get drawn after (on top of) larger values.
pickpriority - When using a Render Pick CHOP or a Render Pick DAT, there is an option to have a 'Search Area'. If multiple objects are found within the search area, the pick priority can be used to select one object over another. A higher value will get picked over a lower value. This does not affect draw order, or objects that are drawn over each other on the same pixel. Only one will be visible for a pick per pixel.
wcolor - ⊞ - Use the R, G, and B fields to set the Component's color when displayed in wireframe shading mode.
lightmask - By default all lights used in the Render TOP will affect geometry renderer. This parmaeter can be used to specify a sub-set of lights to be used for this particular geometry. The lights must be listed in the Render TOP as well as this parameter to be used.
Parameters - Extensions Page
The Extensions parameter page sets the component's python extensions. Please see extensions for more information.
reinitextensions - Recompile all extension objects. Normally extension objects are compiled only when they are referenced and their definitions have changed.
Extension Object 1
extension1 - A number of class instances that can be attached to the component.
Extension Name 1
extname1 - Optional name to search by, instead of the instance class name.
Promote Extension 1
promoteextension1 - Controls whether or not the extensions are visible directly at the component level, or must be accessed through the
.ext member. Example:
Parameters - Common Page
nodeview - ⊞ - Determines what is displayed in the node viewer, also known as the Node Viewer. Some options will not be available depending on the Component type (Object Component, Panel Component, Misc.)
- Default Viewer
default- Displays the default viewer for the component type, a 3D Viewer for Object COMPS and a Control Panel Viewer for Panel COMPs.
- Operator Viewer
opviewer- Displays the node viewer from any operator specified in the Operator Viewer parameter below.
opviewer - Select which operator's node viewer to use when the Node View parameter above is set to Operator Viewer.
Keep in Memory
enablecloning - Control if the OP should be actively cloned. The Pulse button can be used to instantaneously clone the contents.
Enable Cloning Pulse
clone - Path to a component used as the Master Clone.
Load on Demand
loadondemand - Loads the component into memory only when required. Good to use for components that are not always used in the project.
externaltox - Path to a
.tox file on disk which will source the component's contents upon start of a
.toe. This allows for components to contain networks that can be updated independently. If the
.tox file can not be found, whatever the
.toe file was saved with will be loaded.
Reload .tox on Start
reloadtoxonstart - When on (default), the external .tox file will be loaded when the .toe starts and the contents of the COMP will match that of the external .tox. This can be turned off to avoid loading from the referenced external .tox on startup if desired (the contents of the COMP are instead loaded from the .toe file). Useful if you wish to have a COMP reference an external .tox but not always load from it unless you specifically push the Re-Init Network parameter button.
Reload Built-In Parameters
reloadbuiltin - When this checkbox is enabled, the values of the component's built-in parameters are reloaded when the .tox is reloaded.
Save Backup of External
savebackup - When this checkbox is enabled, a backup copy of the component specified by the External
.tox parameter is saved in the
.toe file. This backup copy will be used if the External
.tox can not be found. This may happen if the
.tox was renamed, deleted, or the
.toe file is running on another computer that is missing component media.
Sub-Component to Load
subcompname - When loading from an External
.tox file, this option allows you to reach into the
.tox and pull out a COMP and make that the top-level COMP, ignoring everything else in the file (except for the contents of that COMP). For example if a
.tox file named
geo1 as the Sub-Component to Load, will result in
geo1 being loaded in place of the current COMP. If this parameter is blank, it just loads the
.tox file normally using the top level COMP in the file.
reinitnet - This button will re-load from the external
.tox file (if present), followed by re-initializing itself from its master, if it's a clone.