I am an Architect, and trying to learn Blender for 3d Modelling. Recently I added addon for importing dxf file. Since I work on large project in mm. I set Blender unit to mm. but when I imported the file in Blender 2.8 or even in 2.79b. I am un able to see the drawing in blender and it took quite while to zoom once it is zoom I am unable to work. Since zoom does not work properly.

Please help if i am doing anything wrong.



Your problem here is likely viewport clipping. Its values can be adjusted in the n panel, view tab:

enter image description here

You also need to make sure the unit scale is the same in the DXF files as in your Blender scene. Default Blender unit scale is 1 so in metric unit system 1 unit matches 1 meter. This means that when you export to DXF from another software you must ensure units are set to meters in order to import them to Blender at correct scale later, or you can adjust the unit scale while importing:

enter image description here

So if the DXF file is saved with units set to millimeters and you are working in 2.80 with Unit System set to Metric, Unit Scale set to 1.0(1 meter), and Length set to Millimeter like this: enter image description here

you would need to set unit scale to 0.001 while importing because a millimeter is 0.001 of a meter.

Blender 2.80 and 2.79 work significantly differently when it comes to units. In 2.79 the units define the unit scale as well, while in 2.80 the unit scale can be adjusted separately.

Why does unit scale matter? Blender stores values in 32bit floats so if you work with very small values on a very large object for example you may run into precision issues. There are also other issues like for example there is a limit to how much you can zoom in depending on your unit scale. It usually does not make much sense to work with meters if you actually work with objects of a millimeter scale. In architecture the objects you work with are not usually a few millimeters in size, they can be several meters in size, so in Blender 2.79 it is better to work with meters instead of millimeters even though they are the standard in architecture. This will help you avoid precision issues and will work smoother in 2.79. 2.80 is improved a lot in this area, and you should be able to work with millimeters fine because you can do that even if your unit scale is set so 1 Blender unit matches 1 meter.

  • $\begingroup$ Thank you Martin, for the answer I am was struggling from past 2 days. Thank you so much. With respect to working in meter, I am use to working in mm for very long time. As suggested by you for the model, yes I can do that. Thank you so much for helping. I am really grateful, as I am absolutely new to Blender. As I use to work on SketchUp while I was doing Job. $\endgroup$ – Tusharbc Jul 12 '19 at 8:54
  • $\begingroup$ Blender 2.80 seems to be a better choice for you then. It will really make life a lot easier with millimeters. I work with architectural drawings myself pretty much every day, even this exact moment as I am writing this :D So I know how it is - mm are the standard here, but still I use meters because I still work in 2.79 at the moment, I find it easier in 2.79. I will switch to mm in 2.8 which will probably be a bit of a process for me now that I am used to converting everything to meters, but I imagine it will make life a whole lot easier. $\endgroup$ – Martynas Žiemys Jul 12 '19 at 10:18
  • $\begingroup$ I am absolutely new to Blender and learning from YouTube tutorial. In fact I waited from Blender 2.8 RC to release. I read a lot that it is very powerful software then SketchUp, So I leaning thank you for your recommendation. I am really grateful. $\endgroup$ – Tusharbc Jul 13 '19 at 11:56
  • $\begingroup$ @tusharbc if an answer helped you, consider marking it as accepted $\endgroup$ – Duarte Farrajota Ramos Nov 2 '19 at 13:50

I had the same problems and what Martynas said it has been the solution to my troubles. When I have to import a DXF file into blender I usually set the viewport to Top an only after that I import it set the unit scale to 0,001 (because I worked in mm) in the preferences and works. I don't know way using the Top View works better instead of perspective one ;)


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