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Anyone who starts learning about CAD drawing eventually will get in touch with the coordinate system of those softwares. They are a powerful and reliable way to control lengths and distances. You can specify a point in space using values for X and Y for a 2D design and eventually include a Z location.
One of those systems has the name of Polar Coordinates, and it uses a combination of distance and angle to locate points and draw entities. A common way to write those coordinates is with a notation like “@distance<angle,” which translates into @1<90 for one unit with a direction of ninety degrees.
In the example below, we have the same system used in AutoCAD and QCAD.
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Do you know that we can use polar coordinates in Blender? The notation used to create the lines is different but is the same principle. We must enable an Add-on called PDT (Precision Drawing Tools) to use this system.
To enable PDT, open the Edit → Preferences menu and search for PDT in the Add-ons tab. Once you enable the Add-on, a new tab appears in the 3D Viewport Sidebar. From the PDT tools, we have a section named PDT Command Line that works in a similar way to a CAD tool.
You can write commands and coordinates there to make extrusions or move your 3D Cursor. For instance, we can use the following commands:
- v: To extrude a vertex
- i: To use an inclination or angle, which works like Polar Coordinates
Next to those two letters, you can write a distance and angle separated by a comma. The command will look like this: vi1,90. If you select a vertex in Edit Mode, use this command with PDT, and press ENTER, you get a line with one unit with a ninety-degree angle.
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There is a noticeable difference in how you write the coordinates from a CAD tool and Blender, but the principle is the same. Since we use a 3D environment in Blender, you must set your Plane in PD before typing any polar coordinates. The example above shows that I'm using the Top(X-Y) option.
Learning to use Blender and CAD
If you want to learn about Blender modeling tools for architecture and CAD, we have a lot of useful resources here in Blender 3D Architect. From complete guides to workshops:
- Blender for architecture (Workshop)
- Blender 4.0: Precise Modeling for Architecture (Paperback) – (eBook)
- Blender for technical drawing (Workshop)
- QCAD for technical drawing (Open-source version of QCAD)
We have the Blender 4.0: Precise Modeling for Architecture covering PDT applied to architectural design from these resources.