Creating fixed-length lines to draw plans
 

Hi chaps,

This seems as if it should be simple, but I'm baffled. I'm using OmniGraffle Pro 5.2.3.

What I want to do: - I've measured out a plot land of irregular shape, and with irregular angles. I want to draw this shape to scale in Omnigraffle. I have the lengths of all the sides measured accurately.

What I am trying do: I'm drawing lines of the correct length in Omnigraffle. I them want to keep their lengths fixed as I change the angles to get them all joined up.

What I am finding: There is no obvious way to have the length of line displayed and keep it fixed as you drag one end-point about at different angles. Once lines are joined up, any indication as to length seems to disapear completely. Combined, this makes a simple task impossible.

Any tips? Anything I'm missing, before I revert to graph paper, pencil and ruler?

I'm no expert but........

I think that there are two approaches. For both set a scale for use in your drawing e.g 1c.m. : 8m.

1. If you use lines then use the inspector to set the dimensions length, width and angle. Move the lines into place by grabbing them in the middle and using the mouse or for greater accuracy use the arrow keys.

2. Use thin rectangles instead of lines. The lengths may be set using the inspector and they may be rotated using the command key with the mouse.

3. To display line lengths just add text to a line by typing and dragging the text to the line or rectangle then select insert variable from the edit menu - try line length for lines or width for rectangles.

best wishes
Simon

Interesting
 

Thanks for the reply Simon,

I think the fundamental problem is that there *is* no length value in a line geometry inspector - just a height & width that vary if you attempt to rotate the line.

However your thin rectangle suggestion may just work - the height and width measurements on rectangles don't change as they rotate. Consistent? No. But there you go.

Thanks once again for taking the time.

Chris

Chris,

Have you spotted that while the width and height of a line do change when its angle is changed the line length variable remains constant, constant that is within rounding errors?

Simon

I asked Bill Van Hecke about something very similar to this at Macworld last week. His suggestion was:
[LIST=1][*]Set up desired scale and grid with Canvas:Size and Canvas:Grid inspectors[*]Draw a straight line, holding the shift key to align with the grid[*]Option-double-click on the line to add a label (might be different depending on your Tool Preferences settings)[*]Edit->Insert Variable->Line Length[*]Bring up the Properties:Geometry inspector and adjust the various label parameters to suit[*]Drag the newly created line over to the side of the diagram and duplicate as needed (or create a stencil, I suppose)[*]Use the knob in the Properties:Geometry inspector when you need a line at a different angle.[/LIST]One thing I've noticed is that label sizes don't get rescaled if you change the scale of the document. I don't see an easy way to redo a bunch of labels at once, so it's probably worth getting that nailed down before you do much drawing, or you might have microscopic or gigantic labels!