Equations and variables for drawings
Each object on a drawing such as a line, circle, or rectangle is defined by a set of properties. For a rectangle, for example, it includes the starting point, length, width and line thickness (weight) and colour ... Values for Properties can be entered at the Properties dialog for each object.
● Select object(s)
● Select: Edit - Properties
The properties often take fixed values, for example, the length of a line; they can also take formula and variables. This allows for Parametric drawings which automatically resize depending on the Product dimensions. The actual sizes are worked out when the drawing is used, for example, in the product library or on a label or printed drawing.
For example in a product (such as a bookshelf) the formula might relate the sizes in the drawing to the overall product dimensions (X, Y and Z). The drawing takes on the correct proportions for each variation of the product or when ordered to a particular size for a customer.
A single drawing can accurately cover a wide range of product variations.
Select the Formula (Fx), variables (@) and lookup ($) buttons to access these items. Also use the function key F2
Perspective parametric drawings
When you create a drawing in the Drawing library the values of variables may not be known as these may depend on answers provided when the a specific product is used, therefore, in the drawing library, the variables are set to the default values from the variables table or are otherwise set to zero.
Product/part dimensions - the product or part dimensions are set in the dimension fields X, Y, Z in the 'Drawing properties' dialog
Product dimensions - X -Width, Y - Height, Z - Depth
Part dimension - X - Length, Y - width, Z - thickness
New drawing via product library - the dimensions are set to the product dimensions (if defined) or to the default dimensions. Dimensions based on formula are evaluated. If the product dimensions are changed (in the product library) the drawing is refreshed when the product is re-opened.
Drawing for two or more products - The drawing takes on the sizes for appropriate product when viewed in the Product library. If the underlying drawing is viewed in the Drawing library the dimensions are taken from those last saved with the drawing. The dimensions are set in a similar way for drawings from the part library.
Drawing extents - A fixed border applies when a drawing is viewed via the product or part library otherwise the drawing extents are not adjusted. In all other displays of a drawing the area shown is that containing all visible objects (Status set to visible) plus a border. These are: form/label printing, display in quote/product requirements screen, printing from product requirements, display in the product library, printing from the product library, display in the part library.
To print all drawings the same size to show relative scale draw a rectangle around the drawing
When a new drawing is created by double clicking in the display dialog in the product library the extents are calculated from the product dimensions and vanishing point. The vanishing point is set to the default. When calculating the visible drawing are only the start point of text objects is taken into account.
Editing/rotating/moving - Editing and rotating overwrites any formula. Moving maintains any formula and makes the appropriate adjustments. Snapping to lines overwrites all formula.
Links - Any formula in the link are evaluated using the Link product sizes but any variables in the Link are evaluated using the product variables of the main drawing.
Merge - Any formula in the merged drawing are evaluated using the current drawing product dimensions.
Evaluate drawing formula in the Product library and Part library - The default setting for a variable is used to evaluate variables in the drawing (for the screen drawing and for printouts). If the part or product has defined dimensions then these used to evaluate formula containing X, Y, or Z. The actual answers to variables are used when viewing the drawing in the following: Printing directly from Product requirements, The screen picture in, Product requirements and Quote, Product requirements/Quote form and labels, Part labels, Cutting labels, Homag labels, SPC labels.
Perspective parametric drawings - use the perspective functions in formula for this: XP(x,y,z) and YP(x,y,z)
These functions give the perspective point in X and Y respectively of a 3-D point defined by (x,y,z). For example a line from the top front left corner of a box to the top rear left corner would have the following formula:
Xstart = 0
Ystart = Y
Xend = XP(0,Y,Z)
Yend = YP(0,Y,Z)
A hole in the middle of the back panel (assuming back is full size of cabinet) would be
Xstart = XP(X/2,Y/2,Z)
Ystart = YP(X/2,Y/2,Z)
The perspective drawing assumes a ‘cabinet’ view where the width and height are represented by horizontal and vertical lines respectively, and the depth is represented by a lines at approximately 45 degrees, but showing perspective with respect to the vanishing point set in the drawing properties. The vanishing point should not be changed once the drawing has been started.
Notes
- Lookup button is only enabled on text and dimension properties.
