{ "id": "basis_sop", "name": "Basis SOP", "displayName": "Basis SOP", "category": "SOP", "subcategory": "Generators", "version": "", "lastUpdated": "2025-08-07T07:49:57.284Z", "sourceFile": "C:\\Program Files\\Derivative\\TouchDesigner\\Samples\\Learn\\OfflineHelp\\https.docs.derivative.ca\\Basis_SOP.htm", "url": "", "description": "The Basis SOP provides a set of operations applicable to the parametric space of spline curves and surfaces. The parametric space, also known as the \"domain\" of a NURBS or Bzier primitive, is defined by one basis in the U direction and, if the primitive is a surface, another basis in the V direction. The size of the domain is given by the values of the knots that make up the basis.", "summary": "The Basis SOP provides a set of operations applicable to the parametric space of spline curves and surfaces. The parametric space, also known as the \"domain\" of a NURBS or Bzier primitive, is defined ", "details": "", "usage": "", "tips": [], "warnings": [], "parameters": [ { "id": null, "name": "Group", "label": "Group", "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": "spline types are ignored.", "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": "2025-08-07T07:49:57.278Z", "rawData": {}, "sourceElement": null }, { "id": null, "name": "Edit the U Basis", "label": "Edit the U Basis", "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": "ubasis - Enable editing of the U Basis.", "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": "2025-08-07T07:49:57.282Z", "rawData": {}, "sourceElement": null }, { "id": null, "name": "Parameterization", "label": "Parameterization", "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": "Parameterization parameter.", "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": "2025-08-07T07:49:57.282Z", "rawData": {}, "sourceElement": null }, { "id": null, "name": "Unchanged", "label": "Unchanged", "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": "nochange - Does not change the basis. uniform - Distributes all the knots evenly, maintaining the basis origin and length. Recommended only for regular shapes. chord - Computes the knot ratios based on the distances between successive CVs. This is the most common and most effective parameterization method. centripetal - Similar to the chord length method. Recommended for shapes containing sharp turns. manualone - Loads the basis with the knots listed in the \"Knot Sequence\" below. If the input contains several primitives, only the basis of the first spline primitive will be affected. manualall - Same as above + it copies the basis to the basis of all the other spline primitives in the model or in the group. Using this feature on curves that have the point count and degree will generate cleaner surfaces, i.e. surfaces with fewer isoparms. slide - Shift clusters of knots within the basis. See (From ) for discussion.", "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": "2025-08-07T07:49:57.282Z", "rawData": {}, "sourceElement": null }, { "id": null, "name": "Knot Sequence", "label": "Knot Sequence", "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": "uknots - The basis of the first spline primitive in the input loads its knot sequence with the data specified in this field when the is set to . The values must be in ascending order, and their total count must match the number of knots in the basis. To ensure an exact count, click on the button to read the original knot sequence into this field.\t\nNote: Bezier bases cannot have repeated knots. NURBS bases accept repeated knots as long as the knot multiplicity does not exceed the degree of the basis. The first two and last two knots of a NURBS basis must be identical.", "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": "2025-08-07T07:49:57.282Z", "rawData": {}, "sourceElement": null }, { "id": null, "name": "Read Basis", "label": "Read Basis", "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": "uread - Loads the original knots of the basis into the field when the type is .", "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": "2025-08-07T07:49:57.282Z", "rawData": {}, "sourceElement": null }, { "id": null, "name": "Range", "label": "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": "urange - - Range specifies the domain interval to be shifted. All the knots captured in this range are shifted by the same amount as far as the closest neighbouring knot on either side.\n\nurange1 -urange2 -", "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": "2025-08-07T07:49:57.282Z", "rawData": {}, "sourceElement": null }, { "id": null, "name": "Bias", "label": "Bias", "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": "ubias - Bias indicates the direction and the amount of translation. A of 0.5 does not displace the knots at all. As the decreases, the knot cluster migrates closer to its left-neighbouring knot. A greater than 0.5 forces a migration to the right.\t\nSometimes a of 0 or 1 does not clamp the knot cluster to the closest neighbouring knot. The reason for this behaviour is that the knot multiplicity cannot be allowed to exceed the of the basis. For example, an order 4 (degree 3, or \"cubic\") spline can have at most 3 identical knots in sequence.\t\t\t\nWhen sliding the knot of a NURBS basis, a larger area of that spline is affected. This may create the impression than more knots than those in the cluster are being displaced.", "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": "2025-08-07T07:49:57.282Z", "rawData": {}, "sourceElement": null }, { "id": null, "name": "Concatenate", "label": "Concatenate", "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": "uconcat - Indicates whether the bases of the input spline primitives should be concatenated such that the last knot of the first primitive coincides with the first knot of the second primitive, and so on. This operation is performed before the ones below it, thus allowing a whole set of bases to be mapped onto a given interval (usually [0,1]) while enforcing basis continuity.", "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": "2025-08-07T07:49:57.283Z", "rawData": {}, "sourceElement": null }, { "id": null, "name": "Origin", "label": "Origin", "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": "udoorigin - Enables the Origin parameter.", "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": "2025-08-07T07:49:57.283Z", "rawData": {}, "sourceElement": null }, { "id": null, "name": "Length", "label": "Length", "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": "udolength - Enables the Length parameter.", "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": "2025-08-07T07:49:57.283Z", "rawData": {}, "sourceElement": null }, { "id": null, "name": "Scale", "label": "Scale", "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": "udoscale - Enables the Scale parameter.", "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": "2025-08-07T07:49:57.283Z", "rawData": {}, "sourceElement": null }, { "id": null, "name": "Raise to", "label": "Raise to", "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": "uraise - Enables the Raise to parameter.", "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": "2025-08-07T07:49:57.283Z", "rawData": {}, "sourceElement": null }, { "id": null, "name": "Raise U to", "label": "Raise U to", "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": "orderu - The only operation here is raising the order (or degree) of the spline basis. Valid orders range from 2 to 11. Orders lower than the current spline order are ignored. The operation preserves the shape of the primitive.\t\nProduction Tip: Before applying a spline-based texture projection with the Texture , remap the U and/or V bases of the spline surface between 0 and 1 to ensure a complete mapping of the texture. If a single texture map must be shared by several surfaces, the surface bases should be concatenated prior to being remapped.", "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": "2025-08-07T07:49:57.283Z", "rawData": {}, "sourceElement": null }, { "id": null, "name": "Edit the V Basis", "label": "Edit the V Basis", "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": "vbasis - Enable editing of the V Basis.", "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": "2025-08-07T07:49:57.283Z", "rawData": {}, "sourceElement": null }, { "id": null, "name": "Raise V to", "label": "Raise V to", "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": "orderv - The only operation here is raising the order (or degree) of the spline basis. Valid orders range from 2 to 11. Orders lower than the current spline order are ignored. The operation preserves the shape of the primitive.\t\nProduction Tip: Before applying a spline-based texture projection with the Texture , remap the U and/or V bases of the spline surface between 0 and 1 to ensure a complete mapping of the texture. If a single texture map must be shared by several surfaces, the surface bases should be concatenated prior to being remapped.", "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": "2025-08-07T07:49:57.284Z", "rawData": {}, "sourceElement": null } ], "parameterGroups": {}, "codeExamples": [], "pythonExamples": [], "expressions": [], "commonInputs": [], "commonOutputs": [], "relatedOperators": [], "workflowPatterns": [], "images": [], "videos": [], "assets": [], "keywords": [ "basis", "sop", "provides", "operations", "applicable", "parametric", "space", "spline", "curves", "surfaces." ], "tags": [ "SOP", "TouchDesigner", "Basis SOP" ], "searchWeight": 1, "contentHash": "", "processingDate": "2025-08-07T07:49:57.284Z", "processingVersion": "1.0.0", "isValid": true, "validationErrors": [] }