SOP to CHOP
The SOP to CHOP uses a geometry object to choose a SOP from which the channels will be created. The channels are created from the point attributes of a SOP, such as the X, Y and Z of the point position.
From the SOP you can select a subset of the points using Point Groups. The set of attributes that are converted to channels are chosen using the names of the attributes seen on the Info popup of SOP tiles (middle mouse click on a SOP in a SOP network pane).
For data going the opposite direction, see the Channel SOP.
Note: This CHOP works in tandem with the Channel SOP. Point data is modified in CHOPs as regular channel data (samples) and then fed back to geometry as point attributes through the Channel SOP.
Parameters - SOP to CHOP Page
sop - Specifies which Object / SOP contains the geometry you want to fetch.
group - Only points within the specified group are Fetched. If blank, all points are fetched.
method - ⊞ - Choose whether to get the geometry for the current frame or for all frames:
static- Gets the points for the current frame only, and builds one geometry point per sample of the CHOP. There is one channel per Attribute (The default is the P attribute which creates the tx, ty and tz channels).
animated- Good for looking at point XYZ coordinates over the whole animation for SOPs whose shape animates. The CHOP cooks the input once per frame (of the CHOP's frame range), and create a set of channels for every point of the SOP. This can create a lot of channels! Start and End on the Channels page can restrict the frame range that gets created.
attribscope - This selects the attributes of the SOP to acquire. By default, there are three channels for the XYZ position. The "P" attribute is the point position.
You can use any attribute. If you look at the SOP's info and there are other attributes, you can specify them. For example "uv" will get the three texture coordinates. The most common attributes are
- P - Point position (X, Y, Z) - 3 values
- Pw - Point weight - 1 value
- Cd - Point color (red, green, blue) - 3 values
- Alpha - Point alpha - 1 value
- N - Point normal (X, Y, Z) - 3 values
- uv - Point texture coordinates (U, V, W) - 3 values
See Attributes for a complete list of attributes.
renamescope - This parameter matches each channel acquired in the Attribute Scope. There must be one name per attribute value. By default, it translates the P attribute (position of the point) to
tz channels. You can use Pattern Matching to specify multiple channels.
transobj - If a transform object is specified, the point values will be represented relative to that object's origin and rotation.
Organize by Attribute
organize - You can type '
pid' here - then all the channels get sorted properly.
Parameters - Common Page
timeslice - Turning this on forces the channels to be "Time Sliced". A Time Slice is the time between the last cook frame and the current cook frame.
scope - To determine which channels get affected, some CHOPs use a Scope string on the Common page.
Sample Rate Match
srselect - ⊞ - Handle cases where multiple input CHOPs' sample rates are different. When Resampling occurs, the curves are interpolated according to the Interpolation Method Option, or "Linear" if the Interpolate Options are not available.
- Resample At First Input's Rate
first- Use rate of first input to resample others.
- Resample At Maximum Rate
max- Resample to the highest sample rate.
- Resample At Minimum Rate
min- Resample to the lowest sample rate.
- Error If Rates Differ
err- Doesn't accept conflicting sample rates.
exportmethod - ⊞ - This will determine how to connect the CHOP channel to the parameter. Refer to the Export article for more information.
- DAT Table by Index
datindex- Uses the docked DAT table and references the channel via the index of the channel in the CHOP.
- DAT Table by Name
datname- Uses the docked DAT table and references the channel via the name of the channel in the CHOP.
- Channel Name is Path:Parameter
autoname- The channel is the full destination of where to export to, such has
autoexportroot - This path points to the root node where all of the paths that exporting by Channel Name is Path:Parameter are relative to.
exporttable - The DAT used to hold the export information when using the DAT Table Export Methods (See above).
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An Operator Family that reads, creates and modifies 3D polygons, curves, NURBS surfaces, spheres, meatballs and other 3D surface data.
Each SOP has a list of Points. Each point has an XYZ 3D position value plus other optional attributes. Each polygon Primitive is defined by a vertex list, which is list of point numbers.
A parameter in most CHOPs that restricts which channels of that CHOP will be affected. Normally all channels of a CHOP are affected by the operator.
samples-per-second of a CHOP. Each CHOP in your network has a sample rate, whether it is used or not. The overall timeline has a "frame rate", which is the number of animation frames per second, generally your monitor display frequency.
A Time Slice is the time from the last cook frame to the current cook frame. In CHOPs it is the set of short channels that only contain the CHOP channels' samples between the last and the current cook frame.
Exporting is the connection of CHOP channels to parameters of operators. The output of each exporting CHOP is one or more channels, active only while the CHOP Viewer is on. The current value of a channel can be exported to a parameter of any operator, overriding that parameter's value. See Parameter.
Parameters in TouchDesigner are an operator's settings (numbers, menus, flags, strings, paths) which the user can alter. Parameters for any operator can be opened by right-clicking on the operator and selecting "Parameters..." A currently selected operator's parameters can be viewed in a Network Editor by pressing the keyboard shortcut 'p'.