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Modify pattern

Since the Draw patterns window draws all the patterns, we can do two equivalent actions:

  1. Press the left mouse button on any of the patterns.
  2. Write the number (or click side scroll arrows) of the pattern that we wish to modify in the top left box of the screen.

We have many values in the left margin . We are going to comment on them:

General data

  • Number
    Each pattern has a number assigned in the order of creation. However, this number can be changed through the menu Patterns | Renumber patterns.
    We can move from one pattern to another by the side scroll arrows or directly typing the number of the new pattern we want to modify.
  • Pattern name
    The pattern name is a text that we can determine whether we are interested for some reason. The default is: Pat. n, the pattern number being n.
  • Width of the membrane
    This is a value (see Draw patterns) that affects all patterns, but can also be modified from this window for all patterns.
  • Prestress compensation (%)
    This is a value (see Draw patterns) that affects all the patterns, although we can modify it also from this window for all patterns.
  • Cross compensation (%)
    If we are dealing with patterns made on a surface of which dual curvature is very pronounced in the two directions of the pattern, we will have problems in the cross measures of the pattern. In the longitudinal direction we can resolve it with more points (geodesic with more points, for example), but in the cross direction, we cannot do, as there is no intermediate points. To somehow overcome this obstacle, we have the possibility to set a cross compensation. For more information see the entry on the blog.
  • Rotation angle
    It is likely that the first time we visualize a pattern, it remains drawn in a random way and not in landscape direction. We turn it and put it within the width of the membrane. The angle of rotation applied is the value that appears in this box. This value can also be changed by rotating the pattern by mouse, dragging it with the left mouse button pressed.







Graphic information

  • Nodes
    Numbers of nodes are drawn onto the screen


  • Values
    The coordinates of the nodes, in 2D, appear on the screen. We can choose to show real neat pattern coordinates or the coordinates of the new vertices created when drawing the offset (see bellow)


  • Axes
    Axes (longitudinal and transversal for each node) appear on the screen.


  • Inverted
    The pattern is drawn inverted. In fact the pattern from the lower face is drawn. This option is useful when the pattern data have been entered incorrectly and the underside of the pattern is drawn instead of drawing the top face.


  • DXF both: normal + inverted
    Often, when we make a symmetrical membrane, we create only half of the patterns. It is assumed that the other half are symmetrical patterns. However, at the time of printing and cutting these patterns, it is necessary to use all of them, not the half. With this check box, the program creates duplicates, one from the upperside and another from the underside (the symmetric), and then it saves both patterns in the DXF file.
  • modify-pattern3Align nodes

    We have already discussed how we can rotate the pattern graph in the window using the mouse by dragging with the left mouse button pressed. This type of motion, although very fast, is not very accurate.
    Therefore, it is sometimes better to align automatically according to certain criteria:

    - Aligned to the upper side
    - Aligned to the bottom side
    - Aligned to two nodes of the pattern (generally the ends) to achieve that is perfectly aligned within the width of fabric.
    modify-pattern4Origen of coordinates

    When exporting the patterns in a DXF file, all the patterns are aligned to the left. This is not the optimal form for the majority of the times. It would seem better align the patterns one below the other in their natural position. The way to achieve this is to introduce some value in the boxes X0 and Y0, so that the pattern is drawn more to the right or to the left (negative value), above or below.
    modify-pattern5modify-pattern6Offsets

    We have already seen in the paragraph of Draw patterns as we could enter an offset value common to all patterns. This saves time, but it is very possible that some particular pattern needs special offsets.
    We have two possibilities:

  • Regular offset
    Simply modify the default value to apply an offset value to the pattern in question. By modifying the value in the corresponding box will redraw the pattern with its offset in red color. We can also modify this value with the little side arrows.


  • Special offset
    This is a special value, only affects certain edges of the pattern. It is typically used to prepare edges of cable pocket on the perimeter, connections, etc.
    Once fixed the value, directly with the keyboard or by clicking the side arrows, hit the Apply button to put the mouse pointer in selection mode and mark each one of the sides to which this special offset value should be applied .
    The segment joining two correlative nodes on the perimeter of this pattern is understood as one pattern side. You have to go carefully when the nodes are close to each other that may hide very short sides: a zoom may be needed.
  • modify-pattern7Information about the pattern

    Finally we find information data about the pattern: Number of nodes that form the perimeter, Net surface area of the pattern (including the offset), Gross surface area of the pattern, i.e. the amount of fabric (using its width) necessary to cut the pattern and the Pattern factor, which shows us the efficiency in use of the fabric.
    Pattern factor = Gross surface / Net surface (the closer it gets to 1, the higher efficient utilization will be).