How does Blender differ from a CAD software?

Hi. i will be starting higher education as an engineer in some time.
when i started blender it was fun and casual but i have too say one of the reasons was getting a kickstart in the 3d area. i knew blender isn’t a proper CAD software, but the idea was to get 3d basics first and also have fun with it.

that said, i still have no idea how exactly a CAD software is different. can someone here who has used CAD or is aware about it enlighten me?
i plan to learn CAD software so this is important too me.

I’m an architect just learning how to use Blender.

One of the biggest differences between CAD and Blender is CAD is precise to an amazing degree. Blender seems to be more of an organic tool, less concerned with getting it exactly right and more about making it look right. As an engineer, your focus will be on precision. It will also depend on what kind of engineering you intend to do.

A background in modeling will be extremely beneficial regardless.

Too much to explain briefly. Yes precision is one aspect. Also things like resolution, structural analysis, detail and the like.
Here, have link and go explore, as an aspiring engineer, research is going to be a part of your career.

I´d say the 2 major differences are:
Blender -> meshobjects, CAD -> solids/nurbs
Blender -> design/animation, CAD -> preciscion/planning

It is somewhat like:
(canvas and brush) : (ruler and pencil) = Blender : CAD

For 3D CAD I recommend to go to:
FreeCad really is a good alternative to UnigraphicsNX, Catia or SolidEdge.

Here, have link and go explore, as an aspiring engineer, research is going to be a part of your career.

prepare to bang your head against the wall several times, because the methods you used when modeling in Blender will be a lot different from the ones in CAD programs (mostly because they deal with solids/nurbs rather than polygons)…

I work as an engineer though I mostly use AutoCad to bash out 2d drawings but I have used Inventor before. there biggest advantages over blender would be precision, the ease of getting out 2d working drawings or CNC files, to get out a section drawing its as simple as defining a section plane for example, a really big advantage is a tool set that is geared towards doing engineering type of design parametric modeling seriously kicks butt.

thanks for the replies, everyone. i have a slightly better idiea now
@Pixelmass: i did know about CATIA,Pro engineer,autocad,etc. but there websites use too many crappy marketing buzzwords for me to understand.

Whoops! One side is artistic (blender) and the other side is technical (as in real-world applications). Both are fun though, it all just depends on where your mind is pointed…

Easy: a CAD package is directly concerned with physical reality, while a 3D package is not.

The work product of a CAD package really is not an image at all. It’s plans, exploded views, blueprints, bills of materials, raw material quantity and weight estimates, and more. These packages also usually provide rendering capabilities, but for visualization purposes (such as walk-throughs).

A 3D package, on the other hand, is designed to make “stuff that looks good on screen.” And, to represent the lighting, the cameras, and all of the other things involved in creating a visible scene.

Notice that the differences here are: differences in “the software-designer’s intent.” And, usually, you want to stick with the tool that most closely matches your “intent.” When you are constructing models of physical objects for 3D-graphics, sometimes it is very helpful to use a CAD package to do it, then to import the finished model into Blender. But an architect or landscape designer probably would not want to do the opposite.

I would like to see it all wrapped up into one package. Imagine going from conceptual drawings into details and then into a post processor that would generate the machine code that would allow machines to make the parts involved in your conception. Oh well, I suppose we just have to wait… .

imo, arexma said it all. I remember a project that aimed implementing CAD tools in Blender. It had incredible measure tools and drawing tools that totally looked like a CAD program’s. If i’m not mistaken I’ve even seen a video of someone drawing perfect arcs and snapping stuff just like in a CAD program. No news on that :frowning:

Also, boolean operations work the way they’re supposed to in CAD programs. Blender’s booleans just plain suck. That’s partly to do with the fact that CAD is solid modeling whereas Blender is surface modeling.

I am a product and jewelry designer and also teach computer based modeling.

Blender is only usable for modeling organic surfaces which would be to difficult
with NURBS or solids.

Blender is also good for quick mock ups to be honest.

Other then that it cannot serve CAD and engineering at all.

Take a look at T-Splines. It is a nice plug in to auto generate
nurbs surfaces from subdivision surfaces.

Also Catia uses the same idea and Alias Studio has a sculpt element
where you sculpt the car interior and then retrace everything with NURBS

Blender is a nice addition to CAD because engineering tools are only usable
for certain things and here Blender just rocks when it comes to organic modeling.

I think the main difference is the parametric modelling part. If you want to change something in blender, you’d have to change everything related to it by hand. Inventor and the like allow you to change 1 dimension, and a lot of the other parts of the model change, allowing you to not do much when changing the size. (You might have to fix it a little, but not too much). The dimensioning, cross-sections, etc are already implemented by scripts (which i cant’ find, but i did see it once: it was great!), but any sort of parametric modelling is not implemented.

I went from blender to inventor, and thats the biggest difference. (You notice how handy it is in inventor when somebody changes one of the base dimensions by 20mm, causing you to have to fix it).

In my opinion, both has its own uses. You need the CAD software to draw the blueprints or drawings and then you import the cad format into Blender to give it a 3D shape. That’s what I do with my architectural assignments anyway. I draw the DWG in CAD then import it to Blender and render using Yafaray.

when you start getting into cad software I am sure that you will use one of the engineering applications common in our industry and quickly see the difference between blender polygon based modeling and a parametric 2d and 3d environment.

parametric, surfacing, precision, assembly line, physics calculation all that is what makes those apps.

Thanks for the explanations, again.
I’ve been seeing some demo videos.
it seems that in terms of modeling the focus in CAD software seems to be (apart from what you guys have said) making repetitive tasks faster and easier
To just get the job done, since their users will most likely not have professional 3d skills. atleast those i have/will study with consider it just another tool,which can be done wihout, which is the way it should be really.

I’m quite impressed and excited about all the geek stuff though. Looking forward to using them and yes, NURBS!

Organic modeling:

Parametric modeling

Assembly line:

As an engineer you will very often work together with the designers and create
production ready models since designers often only produce a concept in a
CAD software which is fast but not suitable for product testing, assembly, and production.

and here is another great demo

clay sculpting or digital 3d scanning of a clay model
surface analysis
redrafting with nurbs surfaces