{ "id": "null_chop", "name": "Null CHOP", "displayName": "Null CHOP", "category": "CHOP", "subcategory": "Generators", "version": "Available since TouchDesigner 2018+", "lastUpdated": "2025-08-07T07:50:04.903Z", "sourceFile": "C:\\Program Files\\Derivative\\TouchDesigner\\Samples\\Learn\\OfflineHelp\\https.docs.derivative.ca\\Null_CHOP.htm", "url": "", "description": "The Null CHOP is used as a place-holder and does not alter the data coming in.", "summary": "The Null CHOP is used as a place-holder and does not alter the data coming in.", "details": "", "usage": "", "tips": [ "Use Null CHOPs as export endpoints - this lets you swap upstream CHOP networks without re-exporting.", "Set Cook Type to 'Selective' to optimize performance by only recooking downstream when values actually change.", "Use as a 'breakpoint' in your network for debugging - you can inspect values without affecting the chain." ], "warnings": [ "The Selective cook type may cause downstream nodes to cook for other reasons like viewing node contents." ], "parameters": [ { "id": null, "name": "Cook Type", "label": "Cook Type", "group": "General", "page": "", "type": "float", "dataType": "number", "style": "", "defaultValue": null, "minValue": null, "maxValue": null, "step": null, "menuItems": [], "menuLabels": [], "allowCustom": false, "maxLength": null, "pattern": null, "isArray": false, "arraySize": 1, "dimensions": 1, "description": "This controls how nodes downstream from the Null are triggered for recooking when the Null output changes.", "tooltip": "", "help": "", "units": "", "examples": [], "isReadOnly": false, "isAdvanced": false, "isHidden": false, "isAnimatable": true, "isExpression": false, "isPython": false, "dependsOn": [], "affects": [], "linkedTo": [], "expressionLanguage": "", "defaultExpression": "", "commonExpressions": [], "order": 0, "isVisible": true, "conditionalDisplay": null, "isValid": true, "validationErrors": [], "lastUpdated": "2025-08-07T07:50:04.899Z", "rawData": {}, "sourceElement": null }, { "id": null, "name": "Automatic", "label": "Automatic", "group": "General", "page": "", "type": "float", "dataType": "number", "style": "", "defaultValue": null, "minValue": null, "maxValue": null, "step": null, "menuItems": [], "menuLabels": [], "allowCustom": false, "maxLength": null, "pattern": null, "isArray": false, "arraySize": 1, "dimensions": 1, "description": "auto - Downstream nodes are triggered for recooking normally. always - This node and dirty upstream nodes will cook every frame. Downstream nodes will recook every frame their data is requested. selective - Select which criteria will cause downstream nodes to require recooking, using the parameters below. This option can optimize your network by reducing the number of cooks downstream if the upstream has inputs that are time dependent or changes often, but output is mostly static (e.g. a Math rounding a constantly changing float to 0 or 1). The downside is that the nodes upstream of the Null will cook whenever something changes, even if no data is requested downstream. See Cook for more information on when data is requested.", "tooltip": "", "help": "", "units": "", "examples": [], "isReadOnly": false, "isAdvanced": false, "isHidden": false, "isAnimatable": true, "isExpression": false, "isPython": false, "dependsOn": [], "affects": [], "linkedTo": [], "expressionLanguage": "", "defaultExpression": "", "commonExpressions": [], "order": 0, "isVisible": true, "conditionalDisplay": null, "isValid": true, "validationErrors": [], "lastUpdated": "2025-08-07T07:50:04.902Z", "rawData": {}, "sourceElement": null }, { "id": null, "name": "Check Values", "label": "Check Values", "group": "General", "page": "", "type": "float", "dataType": "number", "style": "", "defaultValue": null, "minValue": null, "maxValue": null, "step": null, "menuItems": [], "menuLabels": [], "allowCustom": false, "maxLength": null, "pattern": null, "isArray": false, "arraySize": 1, "dimensions": 1, "description": "checkvalues - Recook when the Null values change.", "tooltip": "", "help": "", "units": "", "examples": [], "isReadOnly": false, "isAdvanced": false, "isHidden": false, "isAnimatable": true, "isExpression": false, "isPython": false, "dependsOn": [], "affects": [], "linkedTo": [], "expressionLanguage": "", "defaultExpression": "", "commonExpressions": [], "order": 0, "isVisible": true, "conditionalDisplay": null, "isValid": true, "validationErrors": [], "lastUpdated": "2025-08-07T07:50:04.902Z", "rawData": {}, "sourceElement": null }, { "id": null, "name": "Check Names", "label": "Check Names", "group": "General", "page": "", "type": "float", "dataType": "number", "style": "", "defaultValue": null, "minValue": null, "maxValue": null, "step": null, "menuItems": [], "menuLabels": [], "allowCustom": false, "maxLength": null, "pattern": null, "isArray": false, "arraySize": 1, "dimensions": 1, "description": "checknames - Recook when the Null channel names change.", "tooltip": "", "help": "", "units": "", "examples": [], "isReadOnly": false, "isAdvanced": false, "isHidden": false, "isAnimatable": true, "isExpression": false, "isPython": false, "dependsOn": [], "affects": [], "linkedTo": [], "expressionLanguage": "", "defaultExpression": "", "commonExpressions": [], "order": 0, "isVisible": true, "conditionalDisplay": null, "isValid": true, "validationErrors": [], "lastUpdated": "2025-08-07T07:50:04.902Z", "rawData": {}, "sourceElement": null }, { "id": null, "name": "Check Range", "label": "Check Range", "group": "General", "page": "", "type": "float", "dataType": "number", "style": "", "defaultValue": null, "minValue": null, "maxValue": null, "step": null, "menuItems": [], "menuLabels": [], "allowCustom": false, "maxLength": null, "pattern": null, "isArray": false, "arraySize": 1, "dimensions": 1, "description": "checkrange - Recook when the Null channel range changes.\t\nPlease note that downstream cooks may also cook for a variety of reasons including viewing the contents of the data while editing nodes, etc.", "tooltip": "", "help": "", "units": "", "examples": [], "isReadOnly": false, "isAdvanced": false, "isHidden": false, "isAnimatable": true, "isExpression": false, "isPython": false, "dependsOn": [], "affects": [], "linkedTo": [], "expressionLanguage": "", "defaultExpression": "", "commonExpressions": [], "order": 0, "isVisible": true, "conditionalDisplay": null, "isValid": true, "validationErrors": [], "lastUpdated": "2025-08-07T07:50:04.902Z", "rawData": {}, "sourceElement": null }, { "id": null, "name": "Time Slice", "label": "Time Slice", "group": "General", "page": "", "type": "float", "dataType": "number", "style": "", "defaultValue": null, "minValue": null, "maxValue": null, "step": null, "menuItems": [], "menuLabels": [], "allowCustom": false, "maxLength": null, "pattern": null, "isArray": false, "arraySize": 1, "dimensions": 1, "description": "timeslice - Turning this on forces the channels to be \"Time Sliced\". A is the time between the last cook frame and the current cook frame.", "tooltip": "", "help": "", "units": "", "examples": [], "isReadOnly": false, "isAdvanced": false, "isHidden": false, "isAnimatable": true, "isExpression": false, "isPython": false, "dependsOn": [], "affects": [], "linkedTo": [], "expressionLanguage": "", "defaultExpression": "", "commonExpressions": [], "order": 0, "isVisible": true, "conditionalDisplay": null, "isValid": true, "validationErrors": [], "lastUpdated": "2025-08-07T07:50:04.902Z", "rawData": {}, "sourceElement": null }, { "id": null, "name": "Scope", "label": "Scope", "group": "General", "page": "", "type": "float", "dataType": "number", "style": "", "defaultValue": null, "minValue": null, "maxValue": null, "step": null, "menuItems": [], "menuLabels": [], "allowCustom": false, "maxLength": null, "pattern": null, "isArray": false, "arraySize": 1, "dimensions": 1, "description": "scope - To determine which channels get affected, some CHOPs use a string on the Common page. See Pattern Matching.", "tooltip": "", "help": "", "units": "", "examples": [], "isReadOnly": false, "isAdvanced": false, "isHidden": false, "isAnimatable": true, "isExpression": false, "isPython": false, "dependsOn": [], "affects": [], "linkedTo": [], "expressionLanguage": "", "defaultExpression": "", "commonExpressions": [], "order": 0, "isVisible": true, "conditionalDisplay": null, "isValid": true, "validationErrors": [], "lastUpdated": "2025-08-07T07:50:04.902Z", "rawData": {}, "sourceElement": null }, { "id": null, "name": "Sample Rate Match", "label": "Sample Rate Match", "group": "General", "page": "", "type": "float", "dataType": "number", "style": "", "defaultValue": null, "minValue": null, "maxValue": null, "step": null, "menuItems": [], "menuLabels": [], "allowCustom": false, "maxLength": null, "pattern": null, "isArray": false, "arraySize": 1, "dimensions": 1, "description": "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.\n\n first - Use rate of first input to resample others. max - Resample to the highest sample rate. min - Resample to the lowest sample rate. err - Doesn't accept conflicting sample rates.", "tooltip": "", "help": "", "units": "", "examples": [], "isReadOnly": false, "isAdvanced": false, "isHidden": false, "isAnimatable": true, "isExpression": false, "isPython": false, "dependsOn": [], "affects": [], "linkedTo": [], "expressionLanguage": "", "defaultExpression": "", "commonExpressions": [], "order": 0, "isVisible": true, "conditionalDisplay": null, "isValid": true, "validationErrors": [], "lastUpdated": "2025-08-07T07:50:04.902Z", "rawData": {}, "sourceElement": null }, { "id": null, "name": "Resample At First Input's Rate", "label": "Resample At First Input's Rate", "group": "General", "page": "", "type": "float", "dataType": "number", "style": "", "defaultValue": null, "minValue": null, "maxValue": null, "step": null, "menuItems": [], "menuLabels": [], "allowCustom": false, "maxLength": null, "pattern": null, "isArray": false, "arraySize": 1, "dimensions": 1, "description": "first - Use rate of first input to resample others. max - Resample to the highest sample rate. min - Resample to the lowest sample rate. err - Doesn't accept conflicting sample rates.", "tooltip": "", "help": "", "units": "", "examples": [], "isReadOnly": false, "isAdvanced": false, "isHidden": false, "isAnimatable": true, "isExpression": false, "isPython": false, "dependsOn": [], "affects": [], "linkedTo": [], "expressionLanguage": "", "defaultExpression": "", "commonExpressions": [], "order": 0, "isVisible": true, "conditionalDisplay": null, "isValid": true, "validationErrors": [], "lastUpdated": "2025-08-07T07:50:04.903Z", "rawData": {}, "sourceElement": null }, { "id": null, "name": "Export Method", "label": "Export Method", "group": "General", "page": "", "type": "float", "dataType": "number", "style": "", "defaultValue": null, "minValue": null, "maxValue": null, "step": null, "menuItems": [], "menuLabels": [], "allowCustom": false, "maxLength": null, "pattern": null, "isArray": false, "arraySize": 1, "dimensions": 1, "description": "exportmethod - - This will determine how to connect the channel to the parameter. Refer to the Export article for more information.\n\n datindex - Uses the docked table and references the channel via the index of the channel in the . datname - Uses the docked table and references the channel via the name of the channel in the . autoname - The channel is the full destination of where to export to, such has geo1/transform1:tx.", "tooltip": "", "help": "", "units": "", "examples": [], "isReadOnly": false, "isAdvanced": false, "isHidden": false, "isAnimatable": true, "isExpression": false, "isPython": false, "dependsOn": [], "affects": [], "linkedTo": [], "expressionLanguage": "", "defaultExpression": "", "commonExpressions": [], "order": 0, "isVisible": true, "conditionalDisplay": null, "isValid": true, "validationErrors": [], "lastUpdated": "2025-08-07T07:50:04.903Z", "rawData": {}, "sourceElement": null }, { "id": null, "name": "DAT Table by Index", "label": "DAT Table by Index", "group": "General", "page": "", "type": "float", "dataType": "number", "style": "", "defaultValue": null, "minValue": null, "maxValue": null, "step": null, "menuItems": [], "menuLabels": [], "allowCustom": false, "maxLength": null, "pattern": null, "isArray": false, "arraySize": 1, "dimensions": 1, "description": "datindex - Uses the docked table and references the channel via the index of the channel in the . datname - Uses the docked table and references the channel via the name of the channel in the . autoname - The channel is the full destination of where to export to, such has geo1/transform1:tx.", "tooltip": "", "help": "", "units": "", "examples": [], "isReadOnly": false, "isAdvanced": false, "isHidden": false, "isAnimatable": true, "isExpression": false, "isPython": false, "dependsOn": [], "affects": [], "linkedTo": [], "expressionLanguage": "", "defaultExpression": "", "commonExpressions": [], "order": 0, "isVisible": true, "conditionalDisplay": null, "isValid": true, "validationErrors": [], "lastUpdated": "2025-08-07T07:50:04.903Z", "rawData": {}, "sourceElement": null }, { "id": null, "name": "Export Root", "label": "Export Root", "group": "General", "page": "", "type": "float", "dataType": "number", "style": "", "defaultValue": null, "minValue": null, "maxValue": null, "step": null, "menuItems": [], "menuLabels": [], "allowCustom": false, "maxLength": null, "pattern": null, "isArray": false, "arraySize": 1, "dimensions": 1, "description": "autoexportroot - This path points to the root node where all of the paths that exporting by Channel Name is : are relative to.", "tooltip": "", "help": "", "units": "", "examples": [], "isReadOnly": false, "isAdvanced": false, "isHidden": false, "isAnimatable": true, "isExpression": false, "isPython": false, "dependsOn": [], "affects": [], "linkedTo": [], "expressionLanguage": "", "defaultExpression": "", "commonExpressions": [], "order": 0, "isVisible": true, "conditionalDisplay": null, "isValid": true, "validationErrors": [], "lastUpdated": "2025-08-07T07:50:04.903Z", "rawData": {}, "sourceElement": null }, { "id": null, "name": "Export Table", "label": "Export Table", "group": "General", "page": "", "type": "float", "dataType": "number", "style": "", "defaultValue": null, "minValue": null, "maxValue": null, "step": null, "menuItems": [], "menuLabels": [], "allowCustom": false, "maxLength": null, "pattern": null, "isArray": false, "arraySize": 1, "dimensions": 1, "description": "exporttable - The used to hold the export information when using the Table Methods (See above).", "tooltip": "", "help": "", "units": "", "examples": [], "isReadOnly": false, "isAdvanced": false, "isHidden": false, "isAnimatable": true, "isExpression": false, "isPython": false, "dependsOn": [], "affects": [], "linkedTo": [], "expressionLanguage": "", "defaultExpression": "", "commonExpressions": [], "order": 0, "isVisible": true, "conditionalDisplay": null, "isValid": true, "validationErrors": [], "lastUpdated": "2025-08-07T07:50:04.903Z", "rawData": {}, "sourceElement": null } ], "parameterGroups": {}, "codeExamples": [], "pythonExamples": [ { "title": "Use Null CHOP for Exports", "code": "# Create Null CHOP for clean exports\nnull1 = op('/project1').create(nullCHOP)\nnull1.name = 'export_null'\nnull1.par.cooktype = 'selective'\nnull1.par.checkvalues = True\n\n# Read values from Null CHOP\nfor chan in null1.chans():\n print(f'{chan.name}: {chan[0]}')", "description": "Null CHOP as an export point with selective cooking" } ], "expressions": [], "commonInputs": [], "commonOutputs": [], "relatedOperators": [], "workflowPatterns": [], "images": [], "videos": [], "assets": [], "keywords": [ "null", "chop", "used", "place-holder", "alter", "data", "coming" ], "tags": [ "CHOP", "TouchDesigner", "Null CHOP" ], "searchWeight": 1, "contentHash": "", "processingDate": "2025-08-07T07:50:04.903Z", "processingVersion": "1.0.0", "isValid": true, "validationErrors": [] }