Stretch 3D Solid

Dan Sautter

 Is there any faster method to changing the length of a group of objects, or to move holes, than the DMPUSHPULL command?  The STRETCH command works well in 2D, but not in Bricscad 3D.  

Tom Foster

Me too - I constantly reach for STRETCH, also FILLET, TRIM, EXTEND etc.

It's one of my dreams, that 3D CAD would deliberately simplify its specialised 3D version of commands, consolidating and rationalising into the familiar 2D format, even though the commands may operate completely differently (but users shouldn't need to know that).
I am sure that would be a big tech challenge, as well as a UI design challenge, involving contextual input to present appropriate version of say STRETCH without it being followed by numerous options, checkboxes, command line variants etc.

In BRICS, we in addition have unrationalised overlap and duplication between traditional 3D commands and the new DM ones.

I am sure these challenges could be elegantly overcome, but am not sure that BRICS sees the need or benefit. Attached is suggestion docx I submitted a while ago, have just updated, but would probably write it differently now.

BIM proposal update.docx

Dan Sautter

 Microstation by Bentley Systems has STRETCH for 3D objects, and several other handy tools which are not available in Bricscad.  It seems that higher-price CAD software offers better performance.

What is the best method for moving holes in Bricscad?  My scheme is to use CYLINDER to plug the unwanted hole, and then UNION.  To create new holes, I use CYLINDER,  and then SUBTRACT.  Please suggest a quicker method.

Roy Klein Gebbinck

You can use DmMove for this. Just select the cylindrical face of one or more holes.
The command can also be used to 'stretch' multiple solids. But you will have to select the end faces one-by-one.

Tom Foster

Thanks for the info in support, but ...
"It seems that higher-price CAD software offers better performance"
I certainly wouldn't say that, in this case. Brics is Acad on steroids, and Acad is on a par with Microstation, price-wise.
In Microstation I constantly wished for Acad-like tools and simplicities. Now maybe here's one going the other way.

Joe Dunfee

 SpaceClaim is a 3D CAD program that has the stretch feature for multiple solids that the OP was seeking.  It is in the BricsCAD price range.  But, in my opinion, SpaceClaim is not a better choice.  The drafting features are poor, and the program features are simplistic... meaning it can get quite tedious to do something that does not fall into the simplistic category.

-Joe

Tom Foster

When we say 'Stretch a Solid', what I have in mind is to box-select the complete side of a window opening and pull it - just as I can in a 2D elevation. Everything would stretch - the horizontal rails of the window frame, all the multi items that comprise the lintol, and ditto the cill.

In doing the box-select you'd have to be careful to not accidentally select other solids that lie behind, but that's a constant danger anyway.

Jason Bourhill

@Dan Sautter:

 Is there any faster method to changing the length of a group of objects

Attach graphics on 3 different methods you can use

1. Select multiple faces using a 'window/crossing window'. The trick here is to use the 'CTRL' key during your selection to cycle through the available options. With 'CTRL' you can: select objects (default); select faces and; select edges. Having made your selection you, then apply your command such as DMPUSHPULL.
2. Use selection tools. From the QUAD you can use selection tools, such as 'Same Area Faces', and 'Aligned Faces'.
3. Select multiple faces. Simply pick the faces you want to work with, then select apply your command via the QUAD.
   

Regards,

Jason Bourhill

CAD Concepts

MultipleFaces-03.gif

MultipleFaces-01.gif

MultipleFaces-02.gif

Jason Bourhill

@Dan Sautter:

to move holes.  

You can use similar selection techniques to above, then use DMMOVE. Use DMDELETE if you want to delete.

If you adjust DMRECOGNIZE in SETTINGS, or via the 'Design Intent' toolbar, then you can quickly change the holes of equal radii on the same solid.

Regards,

Jason Bourhill

CAD Concepts

Jason Bourhill

@Dan Sautter:

The STRETCH command works well in 2D, but not in Bricscad 3D.  

Your right, there is a disconnect between 2D & 3D commands, which is a pity. You have to use different commands depending on whether it is a 2D object, or 3D ACIS Solid.

You can mimic stretch by selecting an edge(s), then use DMMOVE or DMDEFORMMOVE.

Perhaps I'm missing something, but as far as I can see in BricsCAD you can select ACIS body(s), face(s), or edge(s). It would be nice to be able to select vertices, or manipulate vertices via grip points. If this was available, then stretching would be truly possible. Would think it would be very useful for surface meshes.


Regards,

Jason Bourhill

CAD Concepts

Roy Klein Gebbinck

@ Jason:
Thanks for pointing out method 1 (post #8). Believe it or not, but I was actually unaware of this feature. IMO the 3 icons in the Tips widget are hard to read. Because of the bric pattern I always assumed that these options were somehow related to BIM. The dark grey background does not help either.

Jason Bourhill

@Roy Klein Gebbinck:

IMO the 3 icons in the Tips widget are hard to read. Because of the bric pattern I always assumed that these options were somehow related to BIM. The dark grey background does not help either.

I agree, the brick pattern seems a little superfluous. I also find that I get a noticeable delay waiting for the tips widget to appear. Because of this I tend to have made my selection before it has displayed. I can't see anything in SETTINGS that adjusts this.

In some cases it can be easier to run the command first, then make the selection such as with DMPUSHPULL, This command expects to work with faces, so defaults to that selection method, no need to cycle using Ctrl.

Regards,

Jason Bourhill

CAD Concepts

Tom Foster

Anyone want to make a Suggestion out of this, via Service Request?

Roy Klein Gebbinck

@ Tom:
It has now been established that you can use a window to select faces for DmMove, and effectively stretch solids with that command. isn't that what you wish for?

Tom Foster

Yeah, I guess - I did miss that post - call it the famous #8 method!

Still as Jason says 'there is a disconnect between 2D & 3D commands, which is a pity. You have to use different commands depending on whether it is a 2D object, or 3D ACIS Solid'. I wonder whether Brics is still fluid enough to rationalise/consolidate such things. Even leaving aside 2D/3D nomenclature convergence, it seems there's still rationalisation to be done on overlap between dm and traditional Solids tools, as well as how the cake is cut between closely related tools like dmPushPull and dmExtrude>Direction, dmExtrude>Limit and bimDrag>Connect. The whole dm bim bm commands thing seems unsustainable, heading down the 'only makes sense to insiders' trap that Bentley's got into.

Knut Hohenberg

Hello Tom,

I'm mainly with you - the command structure got quite messy with the advent of all these new dm* bm* and bim* stuff, and I think Bricsys knows they have to consolidate this.
However, I think the 'traditional' commands should be left untouched for compatibility reasons, and the new - coherently prefixed - versions should completely supersede them, eg. you should be able to dmpushpull the edge of a polyline or hatch like the face of a solid.
All you would need to do then is to point your shortcuts/aliases to the new ones, and let the old ones rest in peace...

Tom Foster

Wot? that's heresy! Ask old Acad users to abandon Stretch, Trim, Extend, Fillet?!

Joe Dunfee

 I had made similar suggestions a few years ago.  Currently one company I do work for, uses SpaceClaim.  You can use their "stretch" (actually called "move" in their system) to stretch solids in a manner very similar to how 2D stretching works in BricsCAD.  So, it is technically possible with solids.  Though, BricsCAD would have to deal with the ACIS solids, and I have no idea if the ACIS software they license will provide the necessary hooks for them to make it happen like that.

Also, note that some 3D objects work fine with the normal stretch command.  Meshes, and some other objects can be stretched that way.  It can be confusing to use it, if some of the objects on the drawing are ACIS models, and others are Meshes.

-Joe

Knut Hohenberg

@Tom:
I am actually one of those old fossils myself (having used AutoCAD from r10 on), and as such quite reluctant to pick up new goodies like dynamic dimensions, ducs, the quad etc. - unless they prove superior to my old workstyle in every way. At the moment, I switch back and forth between new and old ways of doing things - the new commands are mostly fun to use, but not completely reliable under all circumstances, so I still rely quite heavily on legacy commands, and would prefer them to be kept as a fallback option.
Thus, instead of having souped-up versions of trim, extend, fillet etc. I would rather opt for a 'connect' command that integrates 90% of what trim, extend, fillet/r=0, dmextrude/limit and bimconnect can offer now.

@Joe:
Brep-modeling follows quite different rules than mesh-modeling, but I think these separate worlds are slowly converging - as far as I know, recent versions of the ACIS-kernel do comprise a mesh-like 'solid-light' geometry. Since Spaceclaim is equally based on ACIS, there seems to be room for improvement, but as you mentioned, it may depend on which parts and which version of ACIS Bricsys has licensed.

Alan Liddle

Great demonstrations using .gifs. You can close a hole by pulling the inside face of the hole till it closes right over.

@Jason Bourhill:

Attach graphics on 3 different methods you can use

1. Select multiple faces using a 'window/crossing window'. The trick here is to use the 'CTRL' key during your selection to cycle through the available options. With 'CTRL' you can: select objects (default); select faces and; select edges. Having made your selection you, then apply your command such as DMPUSHPULL.
2. Use selection tools. From the QUAD you can use selection tools, such as 'Same Area Faces', and 'Aligned Faces'.
3. Select multiple faces. Simply pick the faces you want to work with, then select apply your command via the QUAD.
   

Regards,

Jason Bourhill

CAD Concepts