Windows

There are five main types of window in TreeMaker (as well as assorted dialog boxes). They are:

The following sections describe these windows.

Design Window

Each origami design is its own document and is displayed within a single window. An origami design is composed of a number of interrelated "parts". The different types of parts are called:

Each type of part has a graphical representation in the Design window that can be turned on or off and otherwise altered in various ways through the View Settings window. Each type of part has a characteristic color scheme as well. The color scheme and possibilities for graphical display of each type of part are described below in the View Settings window section.

Figures W-1 to W-4 show four views of a typical window that display all of the different parts. These images are taken from the Mac version of TreeMaker, but other platforms should look similar.

Figure W-1 shows a design window after a tree has been defined in Design View. The visible objects include the nodes and edges of the tree; the paths that form the convex hull of the leaf nodes of the tree; and circles around each leaf node that indicate the minimum amount of paper needed to fold the flaps corresponding to the edges incident on each leaf node. (These are the circles used in "circle packing" origami design.)


Figure W-1.

Figure W-2 shows a design window after the tree has been optimized, also in Design View. Optimization finds the positions of the nodes (and their corresponding crease pattern vertices) that maximizes the size of the resulting base.


Figure W-2.

Figure W-3 shows a design window after the crease pattern has been constructed, again in Design View. Visible are nodes, edges, paths, vertices, and creases, the latter drawn in "AGRH" style. The crease pattern is constructed from the node positions found in optimization.


Figure W-3.

Figure W-4 shows the same design window after the crease pattern has been constructed, now in Plan View. Visible are vertices and creases, with mountain, valley, and unfolded creases identified, and coordinates given for the vertices.


Figure W-4.

These are many different ways of viewing the same design. As is shown in the next section, you can use the View->Show View Settings/Hide View Settings command to select which parts are shown and how they are shown.

The bottom of the Design window shows the scale of the current design. The scale is the relationship between one edge unit and the size of the paper, and is a measure of how large the folded shape will be relative to the size of the paper. The rest of the window shows all the parts.

The collection of nodes and edges, which specifies the structure of the desired base, is known as a tree. Lines between pairs of nodes on the paper are paths. There is a path between most pairs of nodes, but most paths are not shown most of the time (or in the windows above). Groups of certain paths form larger-scale structures called polys ("poly" is short for "polygon" and I'll use the two terms more or less interchangeably). Each poly contains a portion of the overall crease pattern. The crease pattern is made up of vertices, creases, and facets. The design of an origami base is accomplished in three steps:

  1. Construction of a tree and specification of the desired attributes of the base. This is done by you using various editing tools.
  2. Placement of the nodes in a valid configuration. This is computed by TreeMaker, using a process of optimization, which you can control by various settings and conditions. The node positions form the "skeleton" of the crease pattern.
  3. Construction of the polys, vertices, and creases, forming the crease pattern for the base. This is also computed by TreeMaker.

What parts are shown and how they are shown in the main window can be altered with the View->Show View Settings/Hide View Settings menu command. There are four predefined combinations of view settings that may be set from the View menu:

Other combinations of settings are posible by going to the View Settings window, see below.

When the document is printed, the first page of the printout will contain whatever is in the main design window: the tree, a partially-optimized tree, or the completed crease pattern.

Creating a new Tree

When a window is first opened, it will be in Default View showing a blank square, as shown in Figure W-5.


Figure W-5. Initial window for a newly-created document shows a blank square.

You define the tree by pointing and clicking in the square to draw a stick figure that defines the topology of the desired origami base. Clicking once in the square produces a node at the location of the click, as shown in Figure W-6. Leaf nodes (nodes with 0 or 1 incident edge) are shown by default surrounded by a circle. When a node is selected it (and its surrounding circle) is highlighted, that is, shown with a slightly larger dot/thicker line/darker fill than in the unhighlighted case.


Figure W-6. Clicking once in the blank square creates a new node.

If a single node is highlighted, clicking in another location will add a node with an edge connecting the two, as shown in Figure W-7.


Figure W-7. When a node is highlighted, clicking somewhere else will add an edge from the highlighted node to the location of the click.

When an edge is first created, it will have a default length of 1 unit. As already noted, a node with only one edge attached is called a leaf node. A node with two or more edges attached is called a branch node.

In this example, node 2 is selected, so clicking in a new location will create another new node and edge as shown in Figure W-8.


Figure W-8. Clicking again creates a new leaf node and turns node 2 into a branch node.

You can add branches to the tree --- a branch is an edge that emanates from a branch node --- by selecting the branch node and then clicking elsewhere in the square, as shown in Figure W-9.


Figure W-9. A tree with three leaf nodes and one branch node.

You can select any visible part in the design window by clicking on the part. You can select more than one part at a time and more than one type of part. By holding down the shift and/or modifier keys as you click, you can change the selection:

An exception to the above comes when you add a node by clicking: if you hold down the modifier key (Option on Mac, Alt on Windows, Alt or Control on Linux) while clicking to add a node, the currently selected node is left unchanged. In this way you can repeatedly add new nodes and edges to the same selected node.

Between every two tree nodes is a line called a path. Most of the time, paths are invisible. However, once a third node has been created, the paths that form the convex hull of the nodes (called border paths) will be visibly outlined as shown in Figure W-9.

Each edge of the tree corresponds to a flap of the base. The connections between edges specify the way the flaps are connected. By repeatedly selecting nodes and clicking, you can build up arbitrarily complex trees with any number and arrangement of edges, which will specify a tree of the same complexity.

To remove a node or edge, simply select it by clicking on it and do one of the following:

For information about how to edit attributes of nodes and edges, read on. Editing can happen in three ways:

This last is the topic of the next section.

Inspector Window

The Inspector window is a floating window that displays attributes of the currently-selected part, or if no part is selected, attributes of the tree. If multiple parts are selected, the Inspector shows how many of each type of part there are in the selection. All parts (nodes, edges, paths, polys, vertices, and creases) have attributes associated with them. Some are numerical settings; some describe relationships to other parts. The Inspector window is toggled on and off with the View->Show Inspector/Hide Inspector command.

There is only one Inspector; it always displays information for the active design window. The Inspector displays attributes of the tree or a part of the tree. Some of the part attributes are user-editable; others are computed by TreeMaker.

The Inspector displays different panels depending on what object or objects are selected in the Design View window. The panels are:

The fields of the various inspector panels are described in the following sections.

Inspector: Tree Panel


Figure W-10. The Tree panel displays settings that affect the entire tree.

The Tree panel is shown when nothing is selected. The settings are:

Inspector: Node Panel


Figure W-11. The Node panel displays attributes of a selected node.

A node is identified by its index. The attributes shown in the Node panel are:

Inspector: Edge Panel


Figure W-12. The Edge panel displays attributes of a selected edge.

An edge is identified by its index. The attributes shown in the Edge panel are:

Inspector: Path Panel


Figure W-13. The Path panel displays attributes of a selected path.

A path is identified by its index and by the two nodes that the path connects. The attributes shown in the Path panel are:

None of the attributes of a path are editable; they are all set by TreeMaker.

Inspector: Poly Panel


Figure W-14.The Poly panel displays attributes of a selected poly.

A poly is identified by its index. The attributes shown in the Poly panel are:

None of the attributes of a poly are editable; they are all set by TreeMaker.

Inspector: Condition Panel

The Condition panel displays attributes of a selected condition. There are several different condition panels, one for each type of condition. They are:

A condition is identified by its index. All condition panels display the index of the condition and whether or not the condition is currently feasible. The panels for the individual types of conditions display additional information specific to the type of condition, described below.

Inspector: Condition Node Fixed Panel


Figure W-15. The Condition Node Fixed Panel displays attributes of a Node Fixed condition.

The Node Fixed condition lets you constrain the position of a node in one of several different ways. The attributes shown in the panel are:

The Node Fixed condition replaces the next 4 conditions in this list, which have been deprecated. TreeMaker will read version 4 files that contain the old conditions, but you can only create Node Fixed conditions, which combine the functionality of the version 4 conditions.

Note that it is quite possible to create inconsistent conditions: for example, checking "fixed to paper corner" and "x coordinate fixed" with a value of 0.5. If you set inconsistent conditions, TreeMaker will not find a solution. It is up to you to avoid creating combinations of conditions that are impossible to satisfy.

Inspector: Condition Node Symmetric (v4) Panel


Figure W-16. The Condition Node Symmetric Panel displays attributes of a Node Symmetric condition.

The Node Symmetric condition lets you constrain the position of a node to lie on the line of symmetry. The attributes shown in the panel are:

This condition has been deprecated; you should use the Node Fixed condition in new designs.

Inspector: Condition Node On Edge (v4) Panel


Figure W-17. The Condition Node On Edge Panel displays attributes of a Node on Edge condition.

The Node on Edge condition lets you constrain the position of a node to lie on the edge of the paper (any edge will do). The attributes shown in the panel are:

This condition has been deprecated; you should use the Node Fixed condition in new designs.

Inspector: Condition Node On Corner (v4) Panel


Figure W-18. The Condition Node On Corner (v4) Panel displays attributes of a Node on Corner condition.

The Node on Corner condition lets you constrain the position of a node to lie on one of the four corners of the paper. The attributes shown in the panel are:

This condition has been deprecated; you should use the Node Fixed condition in new designs.

Inspector: Condition Node Fixed (v4) Panel


Figure W-19. The Condition Node Fixed (v4) Panel displays attributes of a Node Position Fixed condition.

The Node Position Fixed condition lets you constrain the X and/or Y coordinate of a node to a fixed value. The attributes shown in the panel are:

This condition has been deprecated; you should use the Node Fixed condition in new designs.

Inspector: Condition Nodes Paired Panel


Figure W-20. The Condition Nodes Paired Panel displays attributes of a Nodes Paired condition.

The Nodes Paired condition lets you constrain two nodes to be mirror images of one another about the line of symmetry. This condition only takes effect if the "Symmetry" checkbox is checked in the tree inspector. The attributes shown in the panel are:

Inspector: Condition Nodes Collinear Panel


Figure W-21. The Condition Nodes Collinear Panel displays attributes of a Nodes Collinear condition.

The Nodes Collinear condition lets you constrain three nodes to lie in a straight line. The attributes shown in the panel are:

The three nodes must be distinct leaf nodes of the tree.

By setting multiple such conditions, you can constrain more than three nodes to lie in a single line.

Inspector: Condition Edge Length Fixed Panel


Figure W-22. The Condition Edge Length Fixed Panel displays attributes of an Edge Length Fixed condition.

The Edge Length Fixed condition lets you constrain an edge to a fixed length, i.e., constrain its strain to be zero. The attributes shown in the panel are:

Inspector: Condition Edges Same Strain Panel


Figure W-23. The Condition Edges Same Strain Panel displays attributes of an edges same strain condition.

The edges same strain condition lets you constrain two edges to have the same strain when performing a strain optimization. The attributes shown in the panel are:

By setting multiple such conditions, you can constrain more than two edges to all have the same strain.

Inspector: Condition Path Active Panel


Figure W-24. The Condition Path Active Panel displays attributes of a Path Active condition.

The Path Active condition lets you constrain the positions of two nodes so that the path between them is active (and therefore forms an axial crease in the base). You can also specify additional constraints, forcing the path angle to be quantized (one of a set of discrete values) or a fixed value.

The attributes shown in the panel are:

Fixing the path angle and angle quantization are useful in forcing the crease pattern to be more symmetric (and thus more easily foldable). The quantization is defined as an integral division of 360 degrees; for example, for a path with quantization of 4, the allowable angles would be separated by 90 degrees. The offset specifies how the entire pattern is offset from the x axis. For example, with an offset of 45 degrees, the allowed angles would be 45, 135, -135, and -45 degrees.

If you use very many of these conditions, it is likely that the problem will be over-constrained for simple optimization. More commonly, you will first perform a simple optimization, then set a range of path active conditions and perform a strain optimization to find the set of edge lengths that satisfies all of the path activity conditions.

The path quantization condition should be used carefully. If you set path quantization conditions on every active path in a pattern and don't use the same quantization number and offset for every path, it may be impossible to satisfy the conditions for any set of path angles, leading to a failure of convergence.

In general, you should pick an even integer for the quantization. If you set the quantization to an odd value, then be aware that the angle of a path depends on which endpoint comes first in the definition of the path, so a path that satisfies an odd quantization condition will not if its endpoints are reversed. Make sure you really understand what you're doing before you try to apply an odd quantization.

The Path Active condition replaces the next 3 conditions in this list, which have been deprecated. TreeMaker will read version 4 files that contain the old conditions, but you can only create Path Active conditions, which combine the functionality of the version 4 conditions.

Inspector: Condition Path Active (v4) Panel


Figure W-24. The Condition Path Active (v4) Panel displays attributes of a Path Active (v4) condition.

The Path Active (v4) condition lets you constrain the positions of two nodes so that the path between them is active (and therefore forms an axial crease in the base). It does not set any constraint on the path angle.

This condition has been deprecated; you should use the Path Active condition in new designs.

Inspector: Condition Path Angle Fixed (v4) Panel


Figure W-25. The Condition Path Angle Fixed (v4) Panel displays attributes of a Path Angle Fixed (v4) condition.

The Path Angle Fixed (v4) condition lets you constrain the positions of two nodes so that the path between them is active and runs at a specified angle. This is useful in forcing the crease pattern to be more symmetric (and thus more easily foldable). The attributes shown in the panel are:

This condition has been deprecated; you should use the Path Active condition in new designs.

Inspector: Condition Path Angle Quantized (v4) Panel


Figure W-26. The Condition Path Quantized Fixed (v4) Panel displays attributes of a Path Angle Quantized (v4) condition.

The Path Angle Quantized (v4) condition lets you constrain the positions of two nodes so that the path between them is active and runs at some multiple of a specified angle. The attributes shown in the panel are:

This condition has been deprecated; you should use the Path Active condition in new designs.

Inspector: Vertex Panel


Figure W-27. The Vertex panel displays attributes of a selected vertex.

A vertex is identified by its index. The attributes shown in the Vertex panel are:

None of the attributes of a vertex are editable; they are all set by TreeMaker.

Inspector: Crease Panel


Figure W-28. The Crease panel displays attributes of a selected crease.

A crease is identified by its index and by the indices of the two vertices at each end of the crease. The attributes shown in the Crease panel are:

None of the attributes of a crease are editable; they are all set by TreeMaker.

Inspector: Facet Panel


Figure W-29. The Facet panel displays attributes of a selected facet.

A facet is identified by its index. The attributes shown in the Facet panel are:

None of the attributes of a facet are editable; they are all set by TreeMaker.

Inspector: Group Panel


Figure W-30. The Group Panel is displayed when you have multiple parts selected.

The Group Panel is displayed when you have selected multiple parts. It shows the number of each type of part selected and the indices of the selected parts.

Folded Form Window

The Folded Form window is a floating window that displays a silhouette of the folded form if a crease pattern has been fully computed. If the crease pattern is not fully computed, this window will show nothing. The Folded Form window is toggled on and off with the View->Show Folded Form/Hide Folded Form command.


Figure W-31. The Folded Form window displays a silhouette of the folded form of the base computed by TreeMaker.

The Folded Form window shows the folded form as an x-ray view; that is, all creases are shown, even if they would be hidden by layers of paper. All creases are shown with AGRH coloring; that is, axial creases are shown in black, gusset creases in gray, ridge creases in red, and hinge creases in blue.

It always shows the entire base; if you resize the window, the image scales to fill the window. So the size of the folded form image is generally not related to the size of the crease pattern image.

The Folded Form window is for display only; clicking in it will do nothing. However, if you select a vertex, crease, or facet in the main window, it will be shown highlighted in the folded form window. Furthermore, if you select an edge of the tree in the main window, its corresponding flap (consisting of all associated facets) will be highlighted in the Folded Form window.

When the document is printed, the second page of the printout will contain an image of the folded form, if the folded form exists and the Folded Form window is shown. If the Folded Form window is hidden, only the Design window will be printed.

View Settings Window

The View Settings window is a floating window that controls the display of parts in the main window. It lets you turn on and off which parts are displayed and affects how they are displayed.


Figure W-32. The View Settings window displays various settings that affect what is shown in the Design Window.

The View Settings window contains six preset buttons that turn on and off various groups of settings, and nine groups of settings that affect how individual parts are displayed.

View Settings: Presets


Figure W-33. There are six buttons for preset combinations of view settings.

There are six preset buttons at the top of the window that turn on and off various groups of settings. These presets, and their function, are as follows:

Each type of part has a characteristic color scheme and graphical representation. The representation of each part and the individual groups of settings that affect that representation are described in the following sections.

View Settings: Nodes Group


Figure W-38. The Nodes group in the View Settings window.

A node represents an endpoint of the initial tree and is drawn as a black dot with optional text giving its coordinates and other characteristics.

The Nodes group of settings affects how nodes are displayed in the Design window. The controls are:

View Settings: Edges Group


Figure W-39. The Edges group in the View Settings window.

An edge represents a flap in the base and is drawn as a light blue line connecting two nodes, along with a dot near its midpoint and optional text describing some of its attributes. If an edge is pinned (its length cannot be changed without causing a path constraint to be violated), it is drawn in a lighter shade of blue.

The Edges group of settings affects how edges are displayed in the Design window. The controls are:

View Settings: Paths Group


Figure W-40. The Paths group in the View Settings window.

A path represents a distance relationship between two leaf nodes on the tree and their two corresponding vertices on the paper. A path is drawn as a straight line connecting the two relevant nodes. There are paths between all pairs of leaf and/or branch nodes, but only the leaf paths -- paths between leaf nodes -- correspond to meaningful distance relationships.

Because there are so many paths, generally only a subset of paths will be shown. Paths are drawn in one of three colors:

Paths can also be displayed with optional text describing some of their attributes including their associated distance condition and various flags.

The Paths group of settings affects how paths are displayed in the Design window. The controls are:

View Settings: Polys Group


Figure W-41. The Polys group in the View Settings window.

A poly represents a universal molecule, i.e., a portion of the crease pattern that folds flat with its boundary lying on a single line: the axis, if it is a major polygon, or a line parallel to the axis, if it is a sub polygon. A poly is drawn as a pale orange polygon, outlined by slightly darker lines and with a dark dot at its centroid. The polygon, lines, and/or dot can be individually turned on and off with the settings described below.

The Polys group of settings affects how polys are displayed in the Design window. The controls are:

View Settings: Vertices Group


Figure W-42. The Vertices group in the View Settings window.

A vertex is a point where creases come together within the crease pattern. A vertex is displayed as a black dot with optional text describing some of its attributes.

The Vertices group of settings affects how vertices are displayed in the Design window. The controls are:

View Settings: Creases Group


Figure W-43. The Creases group in the View Settings window.

A crease represents a fold line in the crease pattern. (However, any given crease may be flat, i.e., unfolded.) A crease is drawn as a line connecting its two vertices, plus a dot near its midpoint along with optional text describing some of its attributes.

Creases can be drawn with two different color schemes, described below.

The Creases group of settings affects how creases are displayed in the Design window. The controls are:

View Settings: Facets Group


Figure W-44. The Facets group in the View Settings window.

A facet is a polygonal region of the crease pattern outlined by creases. A facet is drawn as a filled polygon in one of two shades of purple with a dot at its centroid and optional text describing some of its attributes. It is also possible to overlay the facets with a representation of the facet ordering graph, which describes the overlap order between adjacent facets, and from which the relative order of any two overlapping facets may be inferred.

The Facets group of settings affects how facets are displayed in the Design window. The controls are:

View Settings: Conditions Group


Figure W-45. The Conditions group in the View Settings window.

A condition represents a geometric relationship imposed on nodes, edges, and/or paths by the user above and beyond the requirements of the path conditions. Conditions are represented in different ways, depending on what objects they affect, but a common feature is a dot connected by a short flag to a node, edge, or group of nodes connected by lines. Conditions come in two colors: light red, if they are not currently feasible (i.e., not currently satisfied), or light purple if they are currently feasible.

The Conditions group of settings affects how conditions are displayed in the Design window. The controls are:

View Settings: Paper Group


Figure W-46. The Paper group in the View Settings window.

The Paper group of settings affects how the paper is displayed in the Design window. The controls are:

Help Window


Figure W-47. The Help window.

The Help window is brought up if you click the Help->Help menu command. The window is resizeable and searchable, and there is a table of contents bar along the left side. You can also print each of the major help sections by clicking on the printer icon within the window, if you would like a hard copy of this documentation.

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