Activity 2: Edit a T-Spline body

In this activity, you use the Edit Form tool to manipulate the box primitive to change its shape based on the inserted canvas.

T-Spline form edited to match the canvas

Recall that the form tool has 16 controls for manipulation that work on surfaces, edges and vertices. The controls are used in any number of combinations to manipulate a T-Spline form. The controls include:

• 3 rotation tools, the controls are, circles on an arc.
• 3 axis translation tools, the controls are, arrows.
• 3 planer translation tools, the controls are, squares.
• 7 scaling tools, the controls are, a center circle and lines.

Edit form controls

Steps

1. Use the Edit Form tool to move T-Spline faces to the top of the knife image canvas.

   1. Select the Right face of the ViewCube, so the Y-axis points to the right, and Z-axis points up.
   
   
   
   2. Deselect Navigation bar > Grid and Snaps > Incremental Move. By having Incremental Move deselected, you can smoothly move the T-Spline geometry as needed.
   3. Select Form > Modify > Edit Form.
   4. Window select the middle set of faces. Hold the left mouse button and drag lower right to upper left over the middle set of faces.
      
      
      
      This drag direction selects all touching and inside faces. With symmetry being used, the faces on the back side are selected when the front faces are selected.
   
   
   
   5. Use the Planar Translation and Rotation manipulators to move the selected faces to align the top of the T-Spline form with the top of the utility knife canvas.
   
   
   

2. Move the middle bottom faces of the T-Spline form to the bottom of the utility knife canvas.

   1. Band select the middle bottom set of faces.
   
   
   
   2. Use the Planar Translation and Rotation manipulators to move the selected faces to align the bottom of the T-Spline form with the top of the utility knife canvas.
   
   
   

3. Move the front faces of the T-Spline form to the front (knife side) of the utility knife canvas.

   1. Band select the front two columns of faces.
   
   
   
   2. Use the Planar Translation and Rotation manipulators to move the selected faces to align the front of the T-Spline form with the knife opening of the utility knife canvas.
   
   
   

4. Move the back faces of the T-Spline form to the back end of the utility knife canvas.

   1. Band select the back two columns of faces.
   
   
   
   2. Use the Planar Translation and Rotation manipulators to move the selected faces to align the back of the T-Spline form with the back of the utility knife canvas.
   
   
   

5. Continue to align the T-Spline form to the utility knife canvas. The two areas indicated by arrows do not have the T-Spline form aligned with the canvas. These areas are fixed later.
   
   

   1. Use any of the manipulators to get the desired alignment. In addition to Planar and Rotation manipulators, the Scale manipulators may come in handy.
   2. Select one or two faces, edges or vertices to transform, at a time.
   3. Make small adjustments, at a time.
   4. Use the surface boundaries in the image above as a guide for your editing.
   5. Use Undo if you have made one or more adjustments that are not what you want.

6. Insert edges to continue to refine the T-Spline form.

   1. Press Ctrl + click to select the two edges as shown in the image.
   
   
   
   2. Click Form > Modify > Insert Edge.
   3. Drag the direct manipulator to the right, to position the new edges, at an Insert Location of about -0.5.
   
   
   
   4. Click OK.
   5. Select the two edges as shown in the image.
   
   
   
   6. Click Form > Modify > Insert Edge.
   7. Drag the direct manipulator to the right, to position the new edges, at an Insert Location of about -0.5.
   
   
   
   8. Click OK.

7. Use Form > Modify > Edit Form to move inserted edges to align the T-Spline form to the canvas.
   
   When done moving the edges, one problem area will be created and is shown by the arrow in the image below The last problem area is fixed in a future step.

   

   1. Use any of the manipulators to get the desired alignment. In addition to Planar and Rotation manipulators, the Scale manipulators may come in handy.
   2. Select one or two faces, edges or vertices to transform, at a time.
   3. Make small adjustments, at a time.
   4. Use the surface boundaries in the image above as a guide for your editing.
   5. Use Undo if you have made one or more adjustments that are not what you want.

8. Insert points to create an edge for finishing the bottom of the utility knife near the knife blade, where the T-Spline is curved, but the canvas is flatter.

   
   
   The tool Insert points is used as an alternative to Insert Edge because you have more flexibility at the location of the edge to be created when defining points.

   

   1. Click Form > Modify > Insert Point.
   2. Drag the mouse over the edge, just over the edge of the canvas, until a red dot appears indicating the center of the edge. Click to select the edge.
   
   
   
   3. Drag the mouse over the bottom edge, of the T-Spline form, until a red dot appears indicating the center of the edge. Click to select the edge.
   
   
   
   4. Ensure the Insert Mode is Simple.
   5. Click OK.

9. Use Form > Modify > Edit Form to move inserted edges to align the T-Spline form to the canvas. These are the final modifications necessary to finish the T-Spline form of the utility knife.
   
   

10. When you are done editing, click Form > Finish Form to return to the Design Workspace.

Activity 2 summary

In this activity, you modified the T-Spline box primitive shape to the shape of the utility knife on a canvas. The primary tool used was the Edit Form tool.

Canvas with the box T-Spline (top), T-Spline edited to fit the canvas (Bottom)