Group to shape

[CaptainCrunch]

Having a problem understanding how Group to Shape works.

I made 6 points: Imagine the four vertices of a rectangle, then two more points say 5 units higher than the top two of the rectangle. I group to shape the 4 points of the "bottom" rectangle. Then when trying to group to shape the uppermost 4 points to make another rectangle on top of my first one, it does so, but my original rectangle disappears.

Many thanks if you can let me know what I'm doing wrong.

[Support]

Dear CaptainCrunch,

Points can only belong to one shape. Let me know what you are trying to do in the activity and I'll try to offer an alternative method.

Best regards,

Simon

[CaptainCrunch]

Hi Simon,

In the attached image, points marked A and B are two examples of points in common to more than one rectangle ( I drew the rectangles with Irfanview). Now, creating a composite shape is not something I'd necessarily do with Autograph, but I did want to understand the rules of grouping shapes for other applications.

Thanks,
Eric

[Support]

Hi Eric,

Composite shapes are definitely possible but you need to do a little more construction "behind-the-scenes". This construction does not need to be visible to the end-user of the activity you are creating of course, although you might find that the students find the construction interesting and informative.

I like to use vectors and here is how I might start creating the shape you have provided an image of:

http://screencast.com/t/5OPpV4gdPc

The vectors provide you with control over how the different parts of the composite shape will interact together.

Best regards,

Simon