2D Drafting in BlenderBIM?

R by rogueNine on 7 Jul 2023, edited 8 Jul 2023 #

Hey everyone, I am a new user in BlenderBIM, I just recently exposed to this software and I am curious to learn it and utilize it potentials. Previously my workflow was depend on Autocad for making a 2D Draft and then Sketchup to model the 3D version, after that goes to Lumion to create the animation presentation. As I am searching the tutorials online and follow along, I notice that the tutorials I found starts with adding 3D element without any 2D draft, meanwhile I would like to first draft the model in 2D, and then model the 3D using the 2D draft as reference. Is there a way to do this? I mean purely from the blender environment using BlenderBIM add-on (or maybe another add-on but still inside the Blender environment). If so, are there any documentation? Video reference and such? Thanks in advance.

B by bitacovir on 7 Jul 2023, edited 7 Jul 2023 # +1 votes

@rogueNine said:

Hey everyone, I am a new user in BlenderBIM, I just recently exposed to this software and I am curious to learn it and utilize it potentials. Previously my workflow was depend on Autocad for making a 2D Draft and then Sketchup to model the 3D version, after that goes to Lumion to create the animation presentation. As I am searching the tutorials online and follow along, I notice that the tutorials I found starts with adding 3D element without any 2D draft, meanwhile I would like to first draft the model in 2D, and then model the 3D using the 2D draft as reference. Is there a way to do this? I mean purely from the blender environment using BlenderBIM add-on (or maybe another add-on but still inside the Blender environment). If so, are there any documentation? Video reference and such? Thanks in advance.

Yes. You can.

Blender can import image file formats to use as reference for your modelling. There are tutorials using photos of technical drawings of houses.

Also, Blender can import SVG files. Just convert your technical drawing to SVG using inkscape or any other software and import it in Blender.

Finally, Blender can import DXF format. You just need to turn on the addon already installed in Blender in menu Edit - Preference - Add-ons. It's not perfect and some geometries and text cannot be imported but it works. Just convert your drawing into DXF format (as old as possible). Also it helps if you split and simplify the drawing.

Now. If you want to draw 2D in Blender... that is different. Blender is not a 2D CAD. It will be more productive to use a CAD software for 2D drawing. But there are already few methods to do some basic 2D drawing into Blender. For instance the addon https://www.cadsketcher.com/

Also you can explore Grease Pencil for sketching...

M by Moult on 7 Jul 2023 # +2 votes

You can indeed work purely in 2D. It is no different to working in 3D. Just instead of creating 3D objects, create 2D edges. If you activate the CAD Tool button when in edit mode you will get extend / mitre / fillet / offset / 2-point arc / 3-point arc which should cover most of the basic CAD drafting tools. You'll find the shortcuts and workflow very similar to drawing in something like AutoCAD. You can either use IFC classes for it and later on convert it to 3D objects, or simply have a whole IfcAnnotation that you slowly convert to 3D later on.

I would not recommend CAD Sketcher simply because it is not really meant for drafting buildings and is based off constraints which means that unless you have a highly parametric shape, you risk your shapes "drifting" :) It's great for machine parts though. Greasepencil is great for concept sketching but not for CAD precision.

B by bitacovir on 7 Jul 2023 #

@Moult said:

If you activate the CAD Tool button when in edit mode you will get extend / mitre / fillet / offset / 2-point arc / 3-point arc which should cover most of the basic CAD drafting tools.

Wow! I did not know that part... cool!

S by SavyGust27 on 7 Jul 2023 # +1 votes

@rogueNine said:

Previously my workflow was depend on Autocad for making a 2D Draft and then Sketchup to model the 3D version, after that goes to Lumion to create the animation presentation.

Thats how they taught me how to work, only that i don't use lumion . But now i use Autocad and blender and it is way faster to work that way

My new workflow uses Autocad for the 2d representatio (im currently switchin to Qcad to leave Autodesk completely, but i find the dynamic blocks and the parametric side of autocad to be helpfull in my design) and then i export it to DXF, only that i saw that using the newest format gave me better result. I encourage you to try to see what works best for you. Then i use the DXF importer addon in blender to bring it to blender.

Your DXF file will be imported as curves, you can leave it like that and use it as a reference, or convert it to a mesh, and extrude your walls, the same way you do it in sketch up, but better, because blender keeps the layers you use as well as any blocks. from there its just a mater of modeling the missing details, and then apply materials, if you want to make a render or animation.

I have not seen a tutorial in how to use the workflow i describe, im not sure why, since it is so fast ans so convenient to model using your cad drawings.

Hope it help

R by rogueNine on 8 Jul 2023 #

Thanks for all the responses guys, I really appreciate it. This concept of "open-BIM" thing is awesome, and while I only get the gist of it, I am grateful that there are software out there that are being actively develop to help collaboration amongst disciplines and to unify the workflow in this industry. For the last couple of years I have been slowly switch and stick to the "open-souce side", even switch to Linux Mint for my OS. In my place, many of the civil engineer I know almost always dependent to the Autocad and their family (Revit, Civil3D, and such) and these software are "the standard" for almost every construction-like project. Maybe one of the reason is because at the universities in my place, they only teach the student to use these software and not exposing them to any open-source software alternatives. But that just my personal opinion, on the other hand big thanks to all the people who contribute for the BlenderBIM development and I hope the software will keep getting better and better :)

R by rogueNine on 8 Jul 2023, edited 8 Jul 2023 #

@Moult said:

You can indeed work purely in 2D. It is no different to working in 3D. Just instead of creating 3D objects, create 2D edges. If you activate the CAD Tool button when in edit mode you will get extend / mitre / fillet / offset / 2-point arc / 3-point arc which should cover most of the basic CAD drafting tools. You'll find the shortcuts and workflow very similar to drawing in something like AutoCAD. You can either use IFC classes for it and later on convert it to 3D objects, or simply have a whole IfcAnnotation that you slowly convert to 3D later on.

I would not recommend CAD Sketcher simply because it is not really meant for drafting buildings and is based off constraints which means that unless you have a highly parametric shape, you risk your shapes "drifting" :) It's great for machine parts though. Greasepencil is great for concept sketching but not for CAD precision.

I have tried this and all the command for extend/trim, fillet, and mitre works great. I have more question if I may, what about moving or copy by reference? Not only in edit mode, but also in object mode, say move LineA by its midpoint into LineB midpoint's. Are there any feature like this in native blender (or with add-on)?

Edit:

Nevermind, I have found there is an add-on call "CAD transform" that could perform the object transform as I described above.

M by Moult on 8 Jul 2023 #

@rogueNine indeed CAD Transform is pretty critical for everyone. In addition, Blender is also getting a built-in "basepoint" transform (finally!) which is very similar to CAD Transform and makes some of its features obsolete.

Other add-ons we recommend investigating are https://blenderbim.org/docs/users/other_addons.html

R by rogueNine on 8 Jul 2023 #

@Moult said:

@rogueNine indeed CAD Transform is pretty critical for everyone. In addition, Blender is also getting a built-in "basepoint" transform (finally!) which is very similar to CAD Transform and makes some of its features obsolete.

Other add-ons we recommend investigating are https://blenderbim.org/docs/users/other_addons.html

Alright! Thanks for the feedback, really appreciate it!