Relax Tool Dialog

The Relax Tool dialog offers an advanced toolset for modifying the spacing of selected texture coordinates parametrically, for the purpose of eliminating or minimizing distortion in texture maps.

The dialog provides three different methods for relaxing vertices, plus several numeric parameters and two checkboxes. You can use Relax to separate texture vertices that are too close together to texture easily, and to resolve overlapping areas.

The dialog is non-modal, which means that you can work directly in the editor while keeping the dialog open. You can make a selection of texture vertices, apply relaxation, make a different selection, apply relaxation, and so on, without having to close the Relax Tool dialog.

Tip: When using Relax with complex objects, you might find that vertices in interior sections of the texture mesh don't relax properly because they have nowhere to go. In such cases, try making a seam: Select an edge loop or part of a loop, and then use the Break function to separate the mesh at the seam. Alternatively, you could make a face selection and then use Detach Edge Verts. For example, Select Overlapped Faces Expand Selection Detach Edge Verts will break the selection away from the mesh into a new UV element.
Tip: Effective use of the Relax tools requires that the geometry and texture vertices be in the same order. If you get unexpected results using Relax, try mirroring the texture vertices to reverse their order.

Procedures

To relax texture coordinates:

  1. Select the texture-coordinate vertices (or other sub-objects) to relax. If you don't select any sub-objects, Relax works on all texture coordinates.

    You can make this selection at any sub-object level (Vertex, Edge, or Face), but Relax always works on vertices.

  2. The quickest way to use Relax is by clicking (Relax Until Flat) on the Reshape Elements rollout of the Edit UVWs dialog. Click that, and if it does the job, you're finished.

    If not, undo (Ctrl+Z) and open the Relax Tool dialog by following either UI path at the start of this topic.

    This opens the Relax Tool dialog.

  3. Choose the relax method from the drop-down list:
    • Relax By Face Angles
    • Relax By Edge Angles
    • Relax By Centers

    The default method is Relax By Edge Angles; this usually gives the best results.

  4. Do either of the following:
    • Set the other options and then click Apply. This applies the Amount and Stretch settings for the specfied number of iterations.

      As the relaxing progresses, a message appears showing you which frame is being processed. A frame is equivalent to an iteration.

    • Click Start Relax. This ignores the Iterations setting and initiates a continuous relax process, during which you can which you can change any of the other parameters to see the results in real time.

The appropriate relax method and other settings depend on a variety of conditions, including the complexity and topology of the mesh, so experimentation is usually required. Relaxing is undoable, so if one method doesn't work, undo and try another.

To use Relax to fix overlapping faces:

    This procedure provides general guidelines for resolving overlapping texture faces. It might not work in every case, but it should give you a starting point for correcting most situations.

  1. Open the Edit UVWs dialog and on the lower toolbar, click (Polygon Sub-object Mode).
  2. From the Edit UVWs dialog Select menu, choose Select Overlapped Faces.

    Only the overlapping faces are selected.

  3. Also on the lower toolbar, click (Grow: UV Selection) to select faces surrounding the overlapping faces.

    This gives the overlapping faces a larger area in which to spread out.

  4. Open the Relax Tool dialog.
  5. On the dialog, set Stretch to an intermediate value. If the amount of overlapping is considerable, use 0.5 or higher. If it's relatively small, try 0.1 to 0.3.
  6. Click Apply.

    If this seems to help, continue clicking Apply, or just click Start Relax, and wait until the overlapping is resolved. If not, undo (Ctrl+Z) and try using Relax By Face Angles instead, or increase the Amount value, or change the Stretch value, or use combinations of the above.

Interface

[relax method]

The method used to relax the texture vertices. Choose from the drop-down list:

  • Relax By Face Angles Relaxes the vertices based on the shape of the faces. It tries to align the geometric shape of the face to the UV face. This algorithm is mainly used to remove distortion and not so much to remove overlap, and is best suited for simpler shapes.
  • Relax By Edge Angles This default method is similar to Relax By Face Angles except that it uses the edges that are attached to the vertices as the shape to match. It typically works better than Relax By Face Angles but tends to take longer to reach a solution. This method is bested suited for more complex shapes.
  • Relax By Centers The original Relax method from previous versions of 3ds Max. It relaxes vertices based off the centroids (centers of mass) of their faces. It does not take into account the face or edge shapes/angles so it is mainly useful for removing overlap or for faces that are mostly rectangular.
Iterations

The number of times the Relax settings are applied when you click Apply. Each iteration is applied successively, to the results of the previous iteration. Range=0 to 100000. Default=100.

Amount

The strength of the relaxation applied per iteration. Range=0.0 to 1.0. Default=0.1.

Stretch

The amount of stretching that can occur. Stretching is useful mainly to resolve overlapping texture vertices, at the cost of reintroducing distortion into the texture mesh. Range=0.0 to 1.0. Default=0.0.

Keep Boundary Points Fixed

Controls whether vertices at the outer edges of the texture coordinates are moved. Default=off.

When off, the outer edge of the texture mesh can float, allowing a wider range of the available texture-mapping space to be used. Typically you would keep this off when relaxing an entire element or cluster, so 3ds Max can minimize distortion by moving the edges.

When relaxing an interior subset of vertices, it is recommended you turn this on to prevent the selected vertices from overlapping unselected vertices. For Relax By Edge and Face Angles, turn this off until you get a good solution for the outer boundaries of the mesh and then turn it on to resolve the interior sections.

Save Outer Corners

Preserves the original positions of texture vertices farthest away from the center. Available only with the Relax By Centers method.

Start Relax

Initiates the relax process on a continuous basis, ignoring the Iterations setting. During this time, you can change the other dialog settings and see the results in real time.

To halt the relax process, click outside the dialog, press Esc, or click the same button (“Stop Relax”). To revert to the previous mapping, use Undo (Ctrl+Z).

Apply

Begins the relaxation process using the current settings. As relaxation takes place, a textual progress indicator appears at the bottom of the dialog, showing the current iteration (Process frame) and the total number of iterations being processed.

To abort the relaxation process, press Esc. You can then use Undo (Ctrl+Z) to return to the prior state, if necessary.

Parent topic: UVW Editor Dialogs