Spatial Deform: Grasshopper Introduction

Rhino's CageEdit command's closest equivalent in grasshopper is Spatial Deform. The combination of an already powerful command with grasshopper's interactive nature makes this a very complicated and memory intensive tool to figure out and use. Other than this Q&A and this demo, I really can't find a good example of using Spatial Deform, so here goes a basic introduction:

To use Spatial Deform, you'll need to attach the following:

'G' - the rhino geometry to deform

'S' - a series of points that will define the cage

'F' - the forces applied to each of the points in 'S'

'f' - a falloff equation

Now this script takes advantage of Kangaroo's removeDuplicatePts. If you don't already have it, get it at their website.

Spatial Deformation.gh
Spatial Deformation.3dm example
(links updated 9.18.2013)

This tutorial will teach you to deform a 3 dimensional object similar to rhino's CageEdit.

Cage Dimensions: 

1. Brep: Select the object(s). Let's start with one for now. 

2. BBox: Bounding Box will cage the 3-D geometry into a basic bounding box

3. Explode (Brep Components): will explode the bounding box into 6 surfaces

4. SDivide: split the 6 surfaces into an U by V array of grid points. !Note that it is flattened as output

4a and 4b: Slider # of U and V divisions, respectively.

5. removeDuplicatePts (Kangaroo): simplify the cage points by removing duplicates. 

..

6. Point: Select the attractor point. It will be incorporated in the next step to create a force on each of the cage points.

Force calculations: this secondary part is a demonstration of Deform with an attractor point. It will basically move the cage points as a group halfway to the attractor point.

7.  Average: finds the centroid of your bounding box

8. Point: attractor point. (Same as #6)

9. Vec2Pt (upper left): finds the vectors between each of the cage points and the centroid

10. Vec2Pt (lower left): finds the vector between the centroid and the attractor point

11. Vec2Pt (right): finds the vector to move all the object from the centroid to the attractor point

12. F1 (function): x/2: halves the moving force

Putting it together:

13. String: 1 : falloff set as 1. The default '1/x' produces some thorny and weird objects. Explore at your own risk.
14. Deform: add the inputs.
   -'G' from #1
   -'S' from #5
   -'F' from #12
   -'f' from #13

Spatial Deformation.gh