Moving from FreeCAD to BricsCAD, differences

margob

Hi!

I recently discovered that BricsCAD has native Linux support which is great! I've been using FreeCAD for quite some time and I know that application pretty well. After learning and testing quite a bit, there are some things I have not been able to answer myself.

Questions:

• In FreeCAD, every constraint is defined on a 2d sketch. Any change in a sketch will affect the corresponding solid (e.g. changing some width on a sketch will change the solid as well). In BricsCAD, that doesn't seem to be the case. If I change a drawing, the corresponding extruded solid will not change. Is it possible to get the same behavior in BricsCAD - or do I have to use 3D constraints/paremeters to change solids?
• Splines they are indeed great, but I've been struggling to make these parametric in BricsCAD. Creating a spline, extruding that and then doing Auto-parameterize will not give me any result in which the actual spline can be changed (just the length of the extrusion). Any hints here how I can parameterize a spline - or at least being able to change a solid from a spline?
• In FreeCAD, a fully constrained sketch will be displayed in green (and if it's not fully constrained, the number of dimensions missing are displayed). I've not been able to see this in BricsCAD, but is there a way?

Much appreciated!

Michael Mayer

Generally, FreeCAD works mostly parametric, with all Pros and Cons,
while Bricscad uses basically a non-history based "Destructive Modelling".

So you would work differently in Bricscad.
In 3D you will use its "Direct Modeling" tools and workflow.
Which is not a disadvantage, if you have proper and comfortable tools to do.

On the other hand Bricscad (starting with Pro ?) offers 2D and 3D Constrains
to parametrize objects in a flexible and nearly unlimited way.
So if you like to do that and don't fear the effort you can do, but would directly
constrain 3D object with 3D constraints.

YMMV
but beside those, for me, more intuitive and more flexible, Direct Modeling tools,
Bricscad offers a lot of impressing AI support to do boring repetitive work for you.
(mostly for the BIM version though)
E.g. there is Parametrize, to do all complicated constraints of a bunch of Solids
for you automatically !

margob

I agree with your statements. i will use 3d parameters and constraints for 3d objects.

But what about splines then and 3d objects created from those? It's not very clear how to make those parametric in BricsCAD.

Michael Mayer

Ahm,
I forgot to mention that all these impressing Bricscad Tools work best
for rectilinear geometry.
IMHO there are some weaknesses in 2D and curved 3D maintenance.
(The primary focus of Bricscad, unfortunately, keeping Autocad compatibility
at any price. Which may prevent from using better solutions)

But as for any destructive Modeler (I started learning CAD with Microstation)
you would always keep copies of your initial Paths and Profiles on Backup
Layers and re-create your Loft Objects in case of changes.

margob

Alright, perfect - that's my conclusion as well. Solids from splines need to be re-created again in case the spline needs to be changed.

Thanks Michael!

Michael Mayer

Basically yes.
Maybe someone more experienced may know better solutions or workarounds in Bricscad.
Or this is a point where Bricscad is not so comfortable. Although it might not be a big deal
if you are used to.

I personally would not judge over Parametric vs Destructive Modeling.
(I like both)
Like in 3D Mesh Apps there where also parametric approaches like 3DSMax or Cinema4D
which had their Modifier Stack and it was easy to change path or profiles anytime later.
While there were destructive modelers like Modo, which had the Tools to do similar things
with their editing tools at the whole mesh object. By Action Centers, Soft Selections, all kind
of bending, bulging tools or sculpting tools and such things.
Parametric approaches may be limiting when you want to do things that exceed the tools while
destructive modeling may be less limited but also less comfortable in some workflows.

Bricscad may have room for improvements for non rectilinear geometry editing.

But for typical architectural geometries, where most is 90° based, as an example,
when in Freecad you would adapt your Walls by moving segments of the underlaying
2D polyline,
in Bricscad you would just move (BIMDRAG) one of the Walls and the connected
neighbored Walls would adapt.
(It is a bit cumbersome or limited with rounded or even freeform wall, yes)