Defining Areas by Interactive Segmentation

You can segment a mesh interactively.

Before you begin:
  • When you start Interactive Segmentation, a dialog box is displayed, with computation parameters, and the pointer is displayed as a circular brush. Once you have selected the mesh to process, picking it starts the local edition mode and stop the automatic segmentation computation. So be careful not to pick the mesh if you want to start the segmentation computation.
  • If you modify or replace the input mesh, the local edition may be lost.
  • Set the Display Modes to either Flat or Smooth.
  1. From the Surface Reconstruction section of the action bar, click Interactive Segmentation .
  2. To compute a segmentation, select a mesh.
  3. Set the parameters values.
    • Curvature Sensitivity: Criterion to divide the mesh into areas. 0 correspond to the minimum curvature and 100 to the maximum curvature.
    • Influent Radius: For each vertex, this radius defines a sphere centered on this vertex. All vertices and edges inside this sphere influence the resulting curvature value at this vertex. If the influent radius is small, the result is noisy, if it is large, the curvature is smoothed.

      The proposed value is 1/100 of the diagonal of the bounding box.

  4. Click Apply to start the computation of the areas, or to take the modification of a parameter into account.
    Areas are computed according to the curvature, and then merged.

    The areas are displayed in different colors.



    • You cannot modify the colors of the result.
    • The standard Graphic Fill Color is not taken into account.
    An InteractiveSegmentation.x feature is created.
    Note: You can edit this segmentation to improve it, either before clicking OK or after having created a segmentation.
  5. To edit a segmentation, double-click an existing one, or start a segmentation and pick the mesh.
    A circular brush is attached to the pointer.
  6. Do one of the following:
    • Right-click the brush and define its radius. Brush an area. A new area is created.
    • Create an area by propagation, based on an angle:
      • Right-click the brush and define the required angle between any triangle and its normal.
      • Pick a point (thus a triangle) on the mesh.
      The triangles surrounding this point that fit the angle criterion are merged in a new area.
    • Extend an area: Start brushing within the area to extend, then on the triangles to add.
    • Merge two areas: Hold down Ctrl and drag the brush over the areas you want to merge.
    • Detach an area: Hold Ctrl down and pick the area to detach. It is useful when the main area contains several non-connex subareas.