November 2, 2023 Workshop 13 Notes

PART I: Blend Shapes

Part 1 of this workshop is developed after the on-line tutorials provided in the Robinson Text. For a more complete treatment from within UVA, go directly to the on-line reader and review pages on the Bend Deformer beginning at page 321.

1. Goto to the Surfaces module and create a sphere.
   
   
   
   
2. Make a copy of the second sphere. From the " Edit Menu>Delete By Type" option, select and delete the history of second copy of the original sphere. Make some changes to the shape of the thirds sphere.
3. Go to the Animation Module, select the second sphere, shift-select the third sphere,  shift-select the first sphere , and then to the menu item "Deform>Blend Shape" and select the check-box.
   
   
   
4. Next, go to the Channels dialog at the right side of the screen, and expand the tab INPUTS and then "blendShape1".
   
   
   
   
5. Key frame the original shape as is in frame "0" of the animation.
   
   
   
   
6. Next, go to frame "20", go to the blend shape value for the second shape (e.g., "nurbsSphere2"), adjust the weight from 0 to 1 and key frame the original sphere again. Note that the original shape is deformed accordingly.
   
   
   
   
7. Similary, go to frame "40", go to the blend shape value for the second shape (e.g., "nurbsSphere2"), adjust the weight from 0 to 1 and key frame the original sphere again. Note that the original shape is again deformed accordingly.
   
   
   
   
8. Place the second and third shape on separate layer and turn it off.
9. Playback the animation.

PART II: Use of set Driven Keys

1. Create a sphere and a cone.
2. In the Animation module, go to the menu sequence  "Key> Set Driven Key > Set"
3. Select the sphere, and in the "Set Driven Key" dialog box, go to Load>Select as Driver.
4. Select the Cone, and in the "Set Driven Key" dialog box, go to Load>Select as Driven.
   
   
   
5. Now, connect parts of Drive list with parts of the Driven list. For example, select the "Translate Y" attribute of the sphere with the "Rotate X" attribute of the cone, and set the "key" for each one.
   
   
   
6. Move the sphere up and rotate the cone around the Z axis, and set the key again.
   
   
   
7. Now, move the sphere up and down and the cone is adjusted accordingly. 
8. Finally, key frame the sphere at frame 1, frame 12, and frame 14 and three different positions along the Y axis from its first location in step 5 to its final location in step 6, and playback the animation. Note that the cone is animated as well.
9. Similarly, one can rig a character using the same technique. Using the same methods, the illustration below is developed a with horizontal surface plane rotating around the "X" axis as a driver, and the IK handle on the leg of a skeleton moving up and down along the "Y" axis as the driven. Thus, rotating the horizontal plan drives the up and down motion of the leg.
   
   
   
   
10. Set Driven Key can also be used to modify properties of an object such as a point light or a phong shader.
    
    For example, in the scene file sc1.mb (download this mb file) it is used to drive the RGB values of a point light. Open the Set Driven dialog box and then load the circle as the "Driver" and the light as the "Driven" and see the connections already established in this example.
    
    
    
    
    Alternatively, in the scene file sc2.mb (download this mb file) it is used to drive the incandescent values of a phong shader applied to a sphere. Open the Set Driven Menu and then load the circle as the "Driver" and incandescence property of the Phong shader and the "Driven" and see the connections already established.