In the example here you can draw a line between any two points. Move the cursor around and see how DRAFT IT displays the available snaps, click to select anywhere whether it is an existing point or a 'free' cursor position to define the 1st point of the line. Do this for the other line end. Click a third point to clear the line and start again.
Note: Note for simplicity some snaps are not available in this simulation (perpendicular & tangent).
In this example again drawing a line you can see how easy it is to switch input methods. Click any point to start drawing a line, a dynamic line will be attached from this position to the cursor. There are three options to select from, 'snap', 'X,Y' and 'Polar'. The snap setting as demonstrated in the example above allows selection of existing points on the drawing.
When 'X,Y' is set DRAFT IT will select the next point using X & Y values of the current Units (Millimetres, Centimetres, Metres, Decimal Inches, Fractional Inches, Decimal Feet / Inches, Fractional Feet / Inches are available for selection). When set to 'Polar' dynamic dimensions display the next position by angle and length.
As you can see dynamic dimensions display relative values from the previous point, however if there is no previous position such as when defining the first point of the line then no dynamic dimensions are displayed. The increment of the dimensions is user definable.
In the example above click to start the line and then again to end the line, a third click clears the line allowing you to repeat the process.
In addition to the above DRAFT IT allow relative co-ordinate input. This means at any time a new position can be defined relative to existing entities, eliminating the need in many cases for creating specific construction geometry. This feature is invoked by simply holding down the 'control' key when over an existing snap point to switch on the 'X,Y' or 'Polar' input methods.
Once drawn DRAFT IT entities can be dynamically edited, the example below shows what happens when a line is selected. The rectangles at either end and in the middle are called 'handles'. These can be clicked on and moved. Click on either of the blue handles to move that end of the line or click in the red one to move the entire line.
This is the basis of editing in DRAFT IT. Multiple entities can be selected and modified like this with the option to use dynamic dimensions or snaps to select new positions.
Dimensioning is very easy using DRAFT IT as demonstrated here by this linear dimension example. A linear dimension requires 3 points to be selected, the two points to measure between and one to place the dimension itself. In DRAFT IT this point also controls the dimension orientation.
In our example here move the cursor around to and see how its position affects the proposed dimension. We have already selected the two circle centres as the points to dimension between and we are simulating the possibilities before placing the third dimension point. We have labelled four dotted lines to help explain the possibilities. You will see that if the cursor is between A & B, then the dimension is always horizontal.
A vertical dimension is achieved when the cursor is between C & D but not A & B (i.e. the centre square).
When the cursor is in any of the 4 corners the dimension is aligned to the two points. (i.e. If the cursor is not between the points in both the X (horizontal) & Y (vertical) axis. In the top left and bottom right corners you will notice that the text flips outside of the dimension lines.
Note: You can't actually place the dimension in this example, it is just to demonstrate the relationship between the points.