Creating a Curve on Mesh

You can create a curve lying on a single mono-cell mesh, a surface or a solid.

This task shows you how to:

Before you begin:
  • The resulting curve is a feature. It can be a multi-celled one and it can be closed. You can control the continuity of the curve.
  • You can change the view orientation while creating the curve.
  • Some graphical and statistical information is available during creation.
  • If you are working on mesh with a high number of points and triangles, you can activate only a portion of it to improve performance.
Note: You may need to slightly move the cursor to see the immersive icons change.
See Also
About Curve on Mesh

Create or Edit a Curve on Mesh

You can create a curve by picking a mesh, a surface or a solid. You can edit a curve the same way.

  1. From the Wireframe section of the action bar, click Curve on Mesh .
    1. Select the mesh, surface, or solid that will support the curve.

      Multiselection is not allowed.

    The context toolbar appears.
  2. If you have selected a large support mesh, to improve performance during the creation of the curve:
    1. Click Edit Distance .
    2. Clear the Curve Optimization check box.

      By default, Curve Optimization is not selected.

      Note: When this check box is cleared, the order and number of segments of the curve are not optimized and are equal to the maximum values.

  3. Pick points on the mesh to create the curve.
    The points you pick are the split points of the curve. They are projected on the mesh, along the current view direction. Intermediate points are automatically computed between each couple of split points, and the resulting scan is smoothed to create the curve.
  4. Right-click a point and select a different constraint type from the context toolbar.

    The initial constraint type is Point Continuity.

  5. Press Ctrl+Shift to visualize all the continuity constraints of the current curve.
  6. The scan formed by the split points and the intermediate points is displayed in cyan.
    1. Place the pointer close to a split point.
      It is highlighted in yellow.
    2. Drag a split point to another location.
    3. Modify the tangent ratio.
    4. Modify the tangent orientation.
  7. As you move the pointer along the scan, a green dot is displayed that corresponds to intermediate points. Pick an intermediate point to insert a split point or an internal point, depending on the current type of constraint.
  8. Move the pointer over a section of the curve to see whether it is a dominant curve section or not . Right-click to switch between selecting Dominant Continuity or not.
  9. As you create the curve, click Edit Distance to adjust the Tolerance of smoothing, as well as the maximum order (Max. Order) and maximum number of segments (Max. Segments) of the curve.
  10. Optional: Constrain both curve endpoints by picking an existing 3D point, a curve, a plane, or an edge.
  11. Double-click to complete the curve or click OK from the context toolbar.

Constrain the Curve

You can impose constraints on the extremities of the curve.

  1. Pick an existing 3D point, a curve, a plane, or the edge of a surface.
    Note: When a section of the curve does not lie on the mesh, the internal points you are going to create for that section are not taken into account. A warning message is displayed.
  2. Pick an empty space near a free edge to end or begin a curve exactly on the free edge of the mesh. A new control point is then created automatically on the free edge. In that case, the curve lies totally on the mesh. This control point can be edited like any control point.
    Note: You can use this functionality to create a curve that crosses a mesh completely: The cyan arrows show where to pick, the pink arrows show where the control points are created.

Close the Curve

You can close a curve created on a mesh.

  1. Right-click the final point and click Close Curve.
  2. Deselect the item to undo a Close Curve action.

Create a Dominant Curve Section

You can create a dominant curve section, that is, a section of the curve between two split points that enforces a tangent continuity at those points.

  1. Pick a point and drag the pointer.
    The symbol turns to , which indicates you are in dominant creation mode.
  2. Release the pointer and pick the next split point to create a dominant curve section.

    You exit the dominant creation mode automatically as you pick the split point.