draw_nurbs_interp_modT_draw_nurbs_interp_modDrawNurbsInterpModDrawNurbsInterpMod (Operator)

Name

draw_nurbs_interp_modT_draw_nurbs_interp_modDrawNurbsInterpModDrawNurbsInterpMod — Interactive modification of a NURBS curve using interpolation.

Signature

Description

draw_nurbs_interp_moddraw_nurbs_interp_modDrawNurbsInterpModDrawNurbsInterpModDrawNurbsInterpMod returns the contour ContOutContOutContOutContOutcontOut of a NURBS curve of degree DegreeDegreeDegreeDegreedegree, which has been modified interactively by the user in the window WindowHandleWindowHandleWindowHandleWindowHandlewindowHandle.

In addition to ContOutContOutContOutContOutcontOut the control information of the curve (ControlRowsControlRowsControlRowsControlRowscontrolRows, ControlColsControlColsControlColsControlColscontrolCols, and KnotsKnotsKnotsKnotsknots), the interpolation points (RowsRowsRowsRowsrows, ColsColsColsColscols) specified by the user and the tangents at the first and the last point (TangentsTangentsTangentsTangentstangents) are returned. TangentsTangentsTangentsTangentstangents consists of four values. The first two values correspond to the y (row) and the x (column) value of the tangent at the start of the curve and the second two values to the tangent at the end of the curve, respectively.

The weight vector is not returned because it consists of equal entries. As a consequence one can use 'auto'"auto""auto""auto""auto" as weight vector, if the control information is used in a subsequent call to the operator gen_contour_nurbs_xldgen_contour_nurbs_xldGenContourNurbsXldGenContourNurbsXldGenContourNurbsXld. For more information on NURBS see the documentation of gen_contour_nurbs_xldgen_contour_nurbs_xldGenContourNurbsXldGenContourNurbsXldGenContourNurbsXld.

The input curve is specified by the interpolation points (RowsInRowsInRowsInRowsInrowsIn, ColsInColsInColsInColsIncolsIn), its degree DegreeDegreeDegreeDegreedegree and the tangents TangentsInTangentsInTangentsInTangentsIntangentsIn, such that draw_nurbs_interp_moddraw_nurbs_interp_modDrawNurbsInterpModDrawNurbsInterpModDrawNurbsInterpMod can be applied to the output data of draw_nurbs_interpdraw_nurbs_interpDrawNurbsInterpDrawNurbsInterpDrawNurbsInterp.

You can modify the curve in two ways: by editing the interpolation points, e.g., by inserting or moving points, or by transforming the curve as a whole, e.g., by rotating moving or scaling it. Note that you can only edit the curve if EditEditEditEditedit is set to 'true'"true""true""true""true". Similarly, you can only rotate, move or scale it if RotateRotateRotateRotaterotate, MoveMoveMoveMovemove, and ScaleScaleScaleScalescale, respectively, are set to 'true'"true""true""true""true".

draw_nurbs_interp_moddraw_nurbs_interp_modDrawNurbsInterpModDrawNurbsInterpModDrawNurbsInterpMod starts in the transformation mode. In this mode, the curve is displayed together with 3 symbols: a cross in the middle and an arrow to the right if RotateRotateRotateRotaterotate is set to 'true'"true""true""true""true", and a double-headed arrow to the upper right if ScaleScaleScaleScalescale is set to 'true'"true""true""true""true". To switch into the edit mode, press the Shift key; by pressing it again, you can switch back into the transformation mode.

Transformation Mode

• To move the curve, click with the left mouse button on the cross in the center and then drag it to the new position, i.e., keep the mouse button pressed while moving the mouse.

• To rotate it, click with the left mouse button on the arrow and then drag it, till the curve has the right direction.

• Scaling is achieved by dragging the double arrow. To keep the ratio, the parameter KeepRatioKeepRatioKeepRatioKeepRatiokeepRatio has to be set to 'true'"true""true""true""true".

Edit Mode

In this mode, the curve is displayed together with its interpolation points and the start and end tangent. Start and end point are marked by an additional square. You can perform the following modifications:

• To append new points, click with the left mouse button in the window and a new point is added at this position.

• You can delete the point appended last by pressing the Ctrl key.

• To move a point, drag it with the mouse.

• To insert a point on the curve, click on the desired position on the curve.

• To close respectively open the curve, click on the first or on the last point.

Pressing the right mouse button terminates the procedure. On macOS draw_nurbs_interp_moddraw_nurbs_interp_modDrawNurbsInterpModDrawNurbsInterpModDrawNurbsInterpMod can also be terminated by pressing the escape key.

The appearance of the curve while drawing is determined by the line width, size and color set via the operators set_colorset_colorSetColorSetColorSetColor, set_coloredset_coloredSetColoredSetColoredSetColored, set_line_widthset_line_widthSetLineWidthSetLineWidthSetLineWidth, and set_line_styleset_line_styleSetLineStyleSetLineStyleSetLineStyle. The tangents and all handles are displayed in the second color set by set_colorset_colorSetColorSetColorSetColor or set_coloredset_coloredSetColoredSetColoredSetColored. Their line width is fixed to 1 and their line style is fixed to a drawn-through line.

Attention

In contrast to draw_nurbsdraw_nurbsDrawNurbsDrawNurbsDrawNurbs, each point specified by the user influences the whole curve. Thus, if one point is moved, the whole curve can and will change. To minimize this effects, it is recommended to use a small degree (3-5) and to place the points such that they are approximately equally spaced. In general, uneven degrees will perform slightly better than even degrees.

Execution Information

• Multithreading type: reentrant (runs in parallel with non-exclusive operators).
• Multithreading scope: global (may be called from any thread).
• Processed without parallelization.

Parameters

Result

draw_nurbs_interp_moddraw_nurbs_interp_modDrawNurbsInterpModDrawNurbsInterpModDrawNurbsInterpMod returns 2 (H_MSG_TRUE), if the window is valid. If necessary, an exception is raised.

Possible Predecessors

open_windowopen_windowOpenWindowOpenWindowOpenWindow

Possible Successors

set_coloredset_coloredSetColoredSetColoredSetColored, set_line_widthset_line_widthSetLineWidthSetLineWidthSetLineWidth, set_drawset_drawSetDrawSetDrawSetDraw, set_insertset_insertSetInsertSetInsertSetInsert

Alternatives

draw_xld_moddraw_xld_modDrawXldModDrawXldModDrawXldMod, draw_nurbs_moddraw_nurbs_modDrawNurbsModDrawNurbsModDrawNurbsMod

See also

draw_nurbs_interpdraw_nurbs_interpDrawNurbsInterpDrawNurbsInterpDrawNurbsInterp, gen_contour_nurbs_xldgen_contour_nurbs_xldGenContourNurbsXldGenContourNurbsXldGenContourNurbsXld

Module

Foundation