Polygon-convex

Polygon-convex allows you to create a digital data-base of convex polygons approximating the size and shape of a number of objects such as stone pavers or tile fragments from photos of those objects.

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The data-base created by Polygon-convex is a text file which can be used to recreate the stockpile of 2D shapes for the purpose of packing the shapes together using Intresto's Rocksolver software application.

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How to use Polygon-convex.

1. Take photos of your objects keeping the camera on the same settings and the same distance from each object. Make sure the camera stays in landscape mode for all photos. First check that the biggest object fits into the camera frame.

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2. Start Polygon-convex and create a new data-base. Menu - New Database - OK

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3. Use the file manager to open the PolygonData folder then open the database which has been created. Menu - Set Working Folder - Yes

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4. Use the file manager to open the first photo then Menu - Draw - Set Scale Distance and touch each end of the scale distance object.

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5. Set the scale for the data-base. You only have to do this on the first image. Accurately position the end points using your finger then enter scale distance (it must be a number larger than 100 so it might be in tenths of an inch or mm). Menu - Files - Set Scale Value

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6. Menu - Draw - Set Origin then touch the middle of the object to create an origin point.

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7. Touch the screen to create a line. To move the line put your finger on the point in the middle of the line (the proximal point) and drag the point around the origin to position it along one side of the object. Surround the object in each photo with a number of lines. The convex polygon formed by the intersection of lines can then be used to approximate the shape of the object.

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8. Make sure all the lines on the screen are used to enclose the object. Any excess lines need to be removed or they cause an error with data processing. Menu - Draw - Delete Lines and then to return to creating lines Menu - Draw - Set Proximal

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9. Save the data-base. Menu - Files - Save Database

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10. Then for each image

Menu - Files - Select Image

Menu - Draw - Set Origin then places lines

Menu - Files - Save Database

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11. When finished Menu - Done - Exit - Yes

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12. For the first 5 users - email the data-base text file containing up to 100 objects to me (Malcolm Lambert) via the email address in the "Email Developer" link below and the 2D objects will be pack together into a rectangular area using Rocksolver. You will receive the layout plan for free.

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If you have access to 2D computational geometry software you can access the x-y coordinates in the data-base to recreate the convex polygon surrounding each object using an intersection of half-spaces.