# RopeNode¶

from panda3d.core import RopeNode

class RopeNode

Bases: PandaNode

This class draws a visible representation of the NURBS curve stored in its NurbsCurveEvaluator. It automatically recomputes the curve every frame.

This is not related to NurbsCurve, CubicCurveseg or any of the ParametricCurve-derived objects in this module. It is a completely parallel implementation of NURBS curves, and will probably eventually replace the whole ParametricCurve class hierarchy.

Inheritance diagram

enum NormalMode
enumerator NM_none = 0

Don’t generate normals.

enumerator NM_vertex = 1

Generate vertex (smooth-shaded) normals.

enum RenderMode
enumerator RM_thread = 0

Render the rope as a one-pixel thread using a linestrip.

enumerator RM_tape = 1

Render the rope as a triangle strip oriented to be perpendicular to the tube_up vector.

enumerator RM_billboard = 2

Render the rope as a triangle strip oriented to be perpendicular to the view vector.

enumerator RM_tube = 3

Render the rope as a hollow tube extruded along its length.

enum UVMode
enumerator UV_none = 0

Don’t generate UV’s along the curve.

enumerator UV_parametric = 1

Generate UV’s based on the parametric coordinates along the curve.

enumerator UV_distance = 2

Generate UV’s in proportion to spatial distance along the curve, by using the distance function to compute the length of each segment.

enumerator UV_distance2 = 3

As above, but don’t bother to take the square root of each segment. The distance is then in proportion to the sum-of-squares of the segments along the rope. If the segments are similar in length, this approximates the proportion of UV_distance while avoiding hundreds of square root operations.

__init__(name: str)
clearMatrix()None

Resets the node’s matrix to identity. See setMatrix().

property curveNurbsCurveEvaluator
Getter

Returns the curve represented by the RopeNode.

Setter

Sets the particular curve represented by the RopeNode.

static getClassType()TypeHandle
getCurve()NurbsCurveEvaluator

Returns the curve represented by the RopeNode.

getMatrix()LMatrix4

Returns the optional matrix which is used to transform each control vertex after it has been transformed into the RopeNode’s coordinate space, but before the polygon vertices are generated.

getNormalMode() → NormalMode

Returns the kind of normals to generate for the rope. This is only applicable when the RopeNodeRenderMode is set to RM_tube.

getNumSlices()int

Returns the number of radial subdivisions to make if RopeNodeRenderMode is RM_tube. It is ignored in the other render modes. See setNumSlices().

getNumSubdiv()int

Returns the number of subdivisions per cubic segment to draw. See setNumSubdiv().

getRenderMode() → RenderMode

Returns the method used to render the rope. See setRenderMode().

getThickness()float

Returns the thickness of the rope. See setThickness().

getTubeUp()LVector3

Returns the normal vector used to control the “top” of the curve, when RopeNodeRenderMode is RM_tube. See setTubeUp().

getUseVertexColor()bool

Returns the “use vertex color” flag. See setUseVertexColor().

getUseVertexThickness()bool

Returns the “use vertex thickness” flag. See setUseVertexThickness().

getUvDirection()bool

Returns true if the rope runs down the U coordinate of the texture, or false if it runs down the V coordinate.

getUvMode() → UVMode

Returns the algorithm to use to generate UV’s for the rope.

getUvScale()float

Returns the scaling factor to apply to generated UV’s for the rope.

static getVertexColorDimension()int

Returns the numeric extended dimension in which the color components should be found. See NurbsCurveEvaluator.setExtendedVertex().

The color components will be expected at (n, n + 1, n + 2, n + 3).

static getVertexThicknessDimension()int

Returns the numeric extended dimension in which the thickness component should be found. See NurbsCurveEvaluator.setExtendedVertex().

hasMatrix()bool

Returns true if the node has a matrix set, false otherwise. See setMatrix().

property matrixLMatrix4
Getter

Returns the optional matrix which is used to transform each control vertex after it has been transformed into the RopeNode’s coordinate space, but before the polygon vertices are generated.

Setter

Specifies an optional matrix which is used to transform each control vertex after it has been transformed into the RopeNode’s coordinate space, but before the polygon vertices are generated.

property normal_mode → NormalMode
Getter

Returns the kind of normals to generate for the rope. This is only applicable when the RopeNodeRenderMode is set to RM_tube.

Setter

Specifies the kind of normals to generate for the rope. This is only applicable when the RopeNodeRenderMode is set to RM_tube; in the other render modes, normals are never generated.

property num_slicesint
Getter

Returns the number of radial subdivisions to make if RopeNodeRenderMode is RM_tube. It is ignored in the other render modes. See setNumSlices().

Setter

Specifies the number of radial subdivisions to make if RopeNodeRenderMode is RM_tube. It is ignored in the other render modes.

Increasing this number increases the roundness of a cross-section of the tube. The minimum value for a dimensional tube is 3; setting it to 2 will get you a thin piece of tape (which is similar to RM_billboard, except it won’t rotate to face the camera).

property num_subdivint
Getter

Returns the number of subdivisions per cubic segment to draw. See setNumSubdiv().

Setter

Specifies the number of subdivisions per cubic segment (that is, per unique knot value) to draw in a fixed uniform tesselation of the curve.

property render_mode → RenderMode
Getter

Returns the method used to render the rope. See setRenderMode().

Setter

Specifies the method used to render the rope. The simplest is RM_thread, which just draws a one-pixel line segment.

resetBound(rel_to: NodePath)None

Recomputes the bounding volume. This is normally called automatically, but it must occasionally be called explicitly when the curve has changed properties outside of this node’s knowledge.

setCurve(curve: NurbsCurveEvaluator)None

Sets the particular curve represented by the RopeNode.

setMatrix(matrix: LMatrix4)None

Specifies an optional matrix which is used to transform each control vertex after it has been transformed into the RopeNode’s coordinate space, but before the polygon vertices are generated.

setNormalMode(normal_mode: NormalMode)None

Specifies the kind of normals to generate for the rope. This is only applicable when the RopeNodeRenderMode is set to RM_tube; in the other render modes, normals are never generated.

setNumSlices(num_slices: int)None

Specifies the number of radial subdivisions to make if RopeNodeRenderMode is RM_tube. It is ignored in the other render modes.

Increasing this number increases the roundness of a cross-section of the tube. The minimum value for a dimensional tube is 3; setting it to 2 will get you a thin piece of tape (which is similar to RM_billboard, except it won’t rotate to face the camera).

setNumSubdiv(num_subdiv: int)None

Specifies the number of subdivisions per cubic segment (that is, per unique knot value) to draw in a fixed uniform tesselation of the curve.

setRenderMode(render_mode: RenderMode)None

Specifies the method used to render the rope. The simplest is RM_thread, which just draws a one-pixel line segment.

setThickness(thickness: float)None

Specifies the thickness of the rope, in pixels or in spatial units, depending on the render mode. See setRenderMode().

The thickness may also be specified on a per-vertex basis. See setUseVertexThickness().

setTubeUp(tube_up: LVector3)None

Specifies a normal vector, generally perpendicular to the main axis of the starting point of the curve, that controls the “top” of the curve, when RopeNodeRenderMode is RM_tube. This is used to orient the vertices that make up the tube. If this vector is too nearly parallel with the starting direction of the curve, there may be a tendency for the whole tube to gimble-lock around its primary axis.

setUseVertexColor(flag: bool)None

Sets the “use vertex color” flag. When this is true, the R, G, B, A vertex color is assumed to be stored as the dimensions n + 0, n + 1, n + 2, n + 3, respectively, of the extended vertex values, where n is the value returned by getVertexColorDimension(). Use NurbsCurveEvaluator.setExtendedVertex() to set these values.

setUseVertexThickness(flag: bool)None

Sets the “use vertex thickness” flag. When this is true, the vertex thickness is assumed to be stored as the dimension getVertexThicknessDimension(), of the extended vertex values. Use NurbsCurveEvaluator.setExtendedVertex() to set these values.

In this mode, the overall thickness is also applied as a scale to the vertex thickness. Not all render modes support vertex thickness.

setUvDirection(u_dominant: bool)None

Specify true to vary the U coordinate down the length of the rope, or false to vary the V coordinate.

setUvMode(uv_mode: UVMode)None

Specifies the algorithm to use to generate UV’s for the rope.

setUvScale(scale: float)None

Specifies an additional scaling factor to apply to generated UV’s along the rope. This scale factor is applied in whichever direction is along the rope, as specified by setUvDirection().

property thicknessfloat
Getter

Returns the thickness of the rope. See setThickness().

Setter

Specifies the thickness of the rope, in pixels or in spatial units, depending on the render mode. See setRenderMode().

The thickness may also be specified on a per-vertex basis. See setUseVertexThickness().

property tube_upLVector3
Getter

Returns the normal vector used to control the “top” of the curve, when RopeNodeRenderMode is RM_tube. See setTubeUp().

Setter

Specifies a normal vector, generally perpendicular to the main axis of the starting point of the curve, that controls the “top” of the curve, when RopeNodeRenderMode is RM_tube. This is used to orient the vertices that make up the tube. If this vector is too nearly parallel with the starting direction of the curve, there may be a tendency for the whole tube to gimble-lock around its primary axis.

property use_vertex_colorbool
Getter

Returns the “use vertex color” flag. See setUseVertexColor().

Setter

Sets the “use vertex color” flag. When this is true, the R, G, B, A vertex color is assumed to be stored as the dimensions n + 0, n + 1, n + 2, n + 3, respectively, of the extended vertex values, where n is the value returned by getVertexColorDimension(). Use NurbsCurveEvaluator.setExtendedVertex() to set these values.

property use_vertex_thicknessbool
Getter

Returns the “use vertex thickness” flag. See setUseVertexThickness().

Setter

Sets the “use vertex thickness” flag. When this is true, the vertex thickness is assumed to be stored as the dimension getVertexThicknessDimension(), of the extended vertex values. Use NurbsCurveEvaluator.setExtendedVertex() to set these values.

In this mode, the overall thickness is also applied as a scale to the vertex thickness. Not all render modes support vertex thickness.

property uv_directionbool
Getter

Returns true if the rope runs down the U coordinate of the texture, or false if it runs down the V coordinate.

Setter

Specify true to vary the U coordinate down the length of the rope, or false to vary the V coordinate.

property uv_mode → UVMode
Getter

Returns the algorithm to use to generate UV’s for the rope.

Setter

Specifies the algorithm to use to generate UV’s for the rope.

property uv_scalefloat
Getter

Returns the scaling factor to apply to generated UV’s for the rope.

Setter

Specifies an additional scaling factor to apply to generated UV’s along the rope. This scale factor is applied in whichever direction is along the rope, as specified by setUvDirection().

property vertex_color_dimensionint

Returns the numeric extended dimension in which the color components should be found. See NurbsCurveEvaluator.setExtendedVertex().

The color components will be expected at (n, n + 1, n + 2, n + 3).

property vertex_thickness_dimensionint

Returns the numeric extended dimension in which the thickness component should be found. See NurbsCurveEvaluator.setExtendedVertex().