Transform
The Transform tool applies geometric transformations to surface objects using precise numeric input. Reorient, rotate, translate, scale, or mirror surfaces around specified axes and centers.
Accessing the Tool
- Navigate to the Surface tab in the ribbon.
- Click Transform in the Transform section.
Description
Perform transformation operations, including reorientation, rotation, translation, scaling, or mirroring, on the target surface object(s). This operation modifies the physical coordinates of the mesh vertices, permanently changing the object geometry.
Transform operations modify the actual vertex coordinates of the surface mesh. This is a destructive operation that changes the object's physical position and orientation. Use Interactive Transform if you need non-destructive preview capabilities.
Target Object(s)
Select which surface objects the transformation applies to:
| Option | Description |
|---|---|
| Active surface | Transform the currently active surface only. |
| Selected surfaces | Transform all currently selected surfaces. |
| Visible surfaces | Transform all visible surfaces. |
| All surfaces | Transform every surface in the project. |
Transformation Tabs
Rotate Tab
Apply rotation around a specified axis.
Rotation Axis
Select one or more axes to rotate around:
- X: Rotate around the X-axis.
- Y: Rotate around the Y-axis.
- Z: Rotate around the Z-axis.
Rotation Angle
| Parameter | Description |
|---|---|
| Angle (°) | The rotation angle in degrees (-360° to 360°). |
Rotation Center
| Parameter | Description |
|---|---|
| Object centroid | When enabled, rotate around the object's bounding box center. When disabled, rotate around the specified point. |
| X (mm) | X-coordinate of the custom rotation center. |
| Y (mm) | Y-coordinate of the custom rotation center. |
| Z (mm) | Z-coordinate of the custom rotation center. |
Press the P key while hovering over any object in the 3D view to pick that point as the rotation center.
Translate Tab
Move the surface along the coordinate axes.
| Parameter | Description |
|---|---|
| X (mm) | Translation distance along the X-axis. |
| Y (mm) | Translation distance along the Y-axis. |
| Z (mm) | Translation distance along the Z-axis. |
Scale Tab
Resize the surface by a scale factor.
| Parameter | Description |
|---|---|
| X | Scale factor along the X-axis (1.0 = no change). |
| Y | Scale factor along the Y-axis (1.0 = no change). |
| Z | Scale factor along the Z-axis (1.0 = no change). |
| Uniform scaling | When enabled, changing one axis updates all axes to maintain proportions. |
Scale factors greater than 1.0 enlarge the object, while factors between 0 and 1.0 shrink it. Negative values invert the object along that axis.
Mirror Tab
Reflect the surface across coordinate planes.
| Parameter | Description |
|---|---|
| X | Mirror across the YZ plane (flip along X-axis). |
| Y | Mirror across the XZ plane (flip along Y-axis). |
| Z | Mirror across the XY plane (flip along Z-axis). |
Select one or more axes to mirror across. Mirroring creates a reflected copy of the geometry.
Matrix Tab
Apply an arbitrary 4×4 transformation matrix for advanced transformations.
The matrix tab displays a 4×4 transformation matrix that can be directly edited. This allows for combined or custom transformations that cannot be achieved with the individual tabs.
| Row | X | Y | Z | Translation |
|---|---|---|---|---|
| X | m0 | m4 | m8 | m12 |
| Y | m1 | m5 | m9 | m13 |
| Z | m2 | m6 | m10 | m14 |
| W | m3 | m7 | m11 | m15 |
Reorient Tab
Apply a six-parameter rigid transform using three translation values and three Euler rotation angles.
Translation
| Parameter | Description |
|---|---|
| X (mm) | Relative translation distance along the X-axis. |
| Y (mm) | Relative translation distance along the Y-axis. |
| Z (mm) | Relative translation distance along the Z-axis. |
Rotation Angles
| Parameter | Description |
|---|---|
| X (°) | Rotation angle around the X-axis. |
| Y (°) | Rotation angle around the Y-axis. |
| Z (°) | Rotation angle around the Z-axis. |
Rotation Center
| Parameter | Description |
|---|---|
| Object centroid | When enabled, rotate around the object's bounding box center. When disabled, rotate around the specified rotation center. |
| X (mm) | X-coordinate of the custom rotation center. |
| Y (mm) | Y-coordinate of the custom rotation center. |
| Z (mm) | Z-coordinate of the custom rotation center. |
When Object centroid is disabled, use the P key while the mouse is over the object to pick the rotation center.
The reorient tab uses relative translation values, not an absolute target position. Rotation uses the object's current bounding box centroid by default, or an explicit rotation center when Object centroid is disabled, using the same XYZ angle convention as Interactive Transform.
Move to Image Center Tab
Automatically translate the surface to the center of the active volume image.
This tab provides a one-click operation to move the target object(s) to the center of the currently active volume dataset. This is useful for aligning imported surfaces with image data.
Workflow
- Open the Transform tool from the Surface tab.
- Select the Target object(s) from the dropdown.
- Navigate to the appropriate transformation tab:
- Reorient: For common six-parameter rigid transforms.
- Rotate: For angular rotation.
- Translate: For positional movement.
- Scale: For resizing.
- Mirror: For reflection.
- Matrix: For custom matrix transformations.
- Move to Image Center: For centering on image data.
- Configure the transformation parameters.
- Click Apply to execute the transformation.
Use Cases
Aligning Imported Geometry
Use Translate to position imported surfaces at the correct location. Use Move to Image Center to quickly center surfaces within image data bounds.
Exchanging Pose With Other Software
Use Reorient when another application provides a position plus three rotation angles. This is often easier than manually building a 4×4 matrix for rigid alignment.
Correcting Orientation
Apply Rotation to correct the orientation of surfaces that were imported with incorrect alignment.
Scaling for Unit Conversion
Use Scale with uniform scaling to convert between unit systems (e.g., multiply by 10 to convert from cm to mm).
Creating Mirrored Anatomy
Use Mirror to create reflected copies of anatomical structures for bilateral comparisons or implant design.
Precise Positioning
Use exact numeric values for precise positioning when preparing surfaces for manufacturing or simulation.
Tips
- Enable Uniform scaling to maintain object proportions when resizing.
- Use Reorient when you need a compact six-value rigid transform instead of a full matrix.
- Use the Object centroid option for intuitive rotation around the object's own center.
- The Matrix tab is useful for applying transformations exported from other software.
- Combine multiple operations by applying them sequentially.
- For interactive manipulation with visual feedback, use the Interactive Transform tool instead.
Related Tools
- Interactive Transform: Transform surfaces interactively using a gizmo widget.
- Global Registration: Automatically align surfaces to minimize distances.