Scale and 3D drawing
When you look at an object in 3D (perspective) the part of the object closest to you appears bigger than the part of it furthest away. This means that the scale changes. You may be used to drawing in scale 1:20 or 1:50, but a constant scale is not possible in 3D drawing (this is actually what makes the object look 3D). We need to use a 3D scale.
Drawing to scale using the 3D calculator
If we can generate a box to the proportions of what we are drawing then we can just put in the details. Generating this box is the key.
The 3D calculator can give values for lines A, B and C (height, length, depth)
(Note that for the ArchiBoard the lengths for B and C are measured along the eye level line.)
Each line has a length in real life and the length it appears on the page.
When you know the real life dimensions (height, width, length) of the object you want to draw, then simply put these values into the 3D calculator and it will give you the lengths of the lines you need to draw on the page to represent the given dimensions. Be sure to draw lines B and C to the correct sides, and note that line A may be off to one side. (When using the calculator for the ArchiBoard, line A is split into two values: the length of line A above the eye level and the length below.)
 Draw a box beginning with line A near the bottom of the page. Make sure it is the correct length.
 Draw lines B and C to the correct lengths.
 Complete the box using the tracking rule in the correct slots.
If you have drawn an object by eye using the board and want to know its real life dimensions then use the 3D calculator once again. This time put in one of the real life dimensions as well as the on page lengths for height width and depth. The calculator will give you the real life dimensions of the object.
If you have values for the real life length of line A and the length of it on the page then you can use the scale lock to find out other heights. Suppose the box is 120mm high on the page and 900mm in real life and I want to mark out another height of 600 mm (in real life). I lock the scale and put these values into the calculator which gives me a result of 80mm.
 Mark out this height on line A
 Project this height along two of the faces. This is the best way to accurately generate heights along the faces. This method is particularly helpful when using the ArchiBoard to draw correct heights of door frames and windows.
Click here for examples using the ArchiBoard.
