[naikrovek]

I think now you can define circles and extrusions parametrically. I'm sure I've seen videos of people adjusting circle radii and facet count and it adjusted the parameters and re-tesellated based on the new parameters. Visually you see the polygonal representation you asked for, but at least some things do seem to be parametric underneath if you define them in the proper way.

I also believe I read about parametric model definition being something they are working on more, since so many folks are asking for it. I do hope that comes to fruition. A free parametric modeler would be absolutely lovely.

[JTxt]

Yes, there's some parametric things you can do in Blender. You can have a beizier curve that you can later change the facet count on... and you can use a spin modifier on a shape, but you're not going to get a perfect tangent line off a perfect circle like you can in a proper CAD tool for example. and you can boolean with another object, are you're not able to add a perfect fillet at that intersection.

In Blender, with care and if you're clever, you can do many of the same things you can with a CAD program... good enough for many cases. But Blender is still more of an artist tool than an engineer tool. For serious uses you're going to run into the limits.

There are free cad parametric modelers. FreeCAD is one.

[naikrovek]

Yes, there is FreeCAD. It crashes constantly and is very difficult to use. ..it doesn't really count, in my mind; if it isn't usable, it may as well not exist at all.