Isometric projections are sometimes used in 2D drawings to help visualize how an object looks in three dimensions. Isometric projections are relatively easy to create since parallel edges remain parallel and the scale along all three axis is equal and constant.
QCAD has had an isometric projection tool for some time already. In the current development version of QCAD 3, an isometric grid has been added to extend this support for isometric drafting. The isometric grid is an alternative to the existing orthogonal grid and can be switched on and off using a tool button.
If you are working on a drawing with orthographic and isometric projections, it might be interesting to enable multiple viewports and configure some with an orthographic (regular) grid and others with an isometric one.
This way, you can construct flat, orthographic views of the object in the orthogonal view and project them into another view with an isometric grid. The screen shot shows a drawing with two views: an orthographic view with orthographic projections at the left and a view with an isometric grid on the right.
The drawing plane of the isometric grid can be changed to 'top', 'side' or 'front'. The drawing plane setting effects the display of the meta grid, the mouse cursor crosshairs and the behavior of the orthogonal mode.
To improve QCAD's support for isometric drawings with cylinders, two new projection tools have been added to create orthogonal and isometric projections of entities onto cylinder surfaces. In the screenshot above, all edges of boreholes through cylinders have been created using these new tools.
Update: A snapshot release of the current development version of QCAD 3 is now available in your download area.