Sectioning 3DFaces and Surfaces

Alan Liddle

Hi

I need to section a building site that has 3dsolids and 3dFaces. The HELP tells me that the "Sectionplane" command will create sections of 3D solids, surfaces and meshes. I can only get it to show me the solids in section - what am I doing wrong?

Thanks Alan

Jason Bourhill

Most likely the 3D Faces are 3DFACE objects, which are wireframe rather than ACIS solids. I believe that Section plane will only work with ACIS solids. Currently you can't create ACIS surfaces in BricsCAD, however you can use the REGION command to convert a 3DFACE to a region, then if you want use UNION to join them all together. I think Section plane will work with a region.

Before you charge of and do this, I suggest you make a backup of your original drawing. If you have lots of 3D faces, then converting them to region could be quite an intense operation!! You may need to break it up into parts, or just convert around you point of interest.

Regards, Jason Bourhill CAD Concepts 

Alan Liddle

 Thanks Jason,

I selected all 3d Faces and converted them to regions. I then selected all regions and extruded them by 10mm to convert them to thin solids. This enables me to create a section with the Background Lines turned off (regions will only show with background lines on so you can't see the actual cut - just a "confusion" of lines). I then created my section and it worked a treat.

I use 12d to create the digital terrain model and do any road or bulk earthworks design and to do the formal cross sections, however we have created concrete footings, pipes, bases, buildings, walls, bunds etc. in 3d using BricsCAD on the DTM and I want to place sections of these solids on the 12d sections of the ground profile. Bingo - it worked. Thanks.

Alan

Jason Bourhill

Great, happy to hear you got it to work. I checked section planes and it does work with regions, so it shouldn't be necessary to extrude them.

An alternative approach might be to create a separate drawing file containing the 3d Faces. Attach this to your target drawing as an xref, then use XCLIP to clip the surface at the same line as your section plane. Assuming this works, it would provide a way to update the surface information without having to take an additional steps.

Regards, Jason Bourhill CAD Concepts 

Alan Liddle

@Jason Bourhill:

Great, happy to hear you got it to work. I checked section planes and it does work with regions, so it shouldn't be necessary to extrude them.

Jason, section plane does work with regions BUT does not cut the section - just includes it in the section as a "background line" so you don't get a single line, but rather all of the strings that make up each region; this results in a messy confusion of lines. By turning the region into a wafer-thin solid you can turn off "background lines" and all you see is the actual slice at the section.

Nuno Gouveia

@Alan Liddle:

Hi

I need to section a building site that has 3dsolids and 3dFaces. The HELP tells me that the "Sectionplane" command will create sections of 3D solids, surfaces and meshes. I can only get it to show me the solids in section - what am I doing wrong?

Thanks Alan

Strangely enough, in the V12 version, SECTIONPLANE would apparently work on 3dfaces and meshes (https://www.bricsys.com/bricscad/help/en_US/V12/CmdRef/source/S/SectionPlane.htm).

It would be great if we could lobby Bricsys staff into making this available again.

Anyone from Bricsys reading this? Would it be possible to section through 3dfaces?

thanks

nuno

Jason Bourhill

The BricsCAD help for V12 is correct. It is referring to ACIS Surfaces & Meshes, not the wireframe types. Admittedly a somewhat ambiguous statement, which is probably why they changed it in later releases.

Regards,

Jason Bourhill

CAD Concepts

Nuno Gouveia

Another thing,

I'm still working with V11 (and considering upgrading in the near future :-)  and in V11 I can't convert 3dfaces to regions. The Region command simply won't take 3dfaces.

Is this normal or am I missing something?

Thanks

Roy Klein Gebbinck

@ Nuno: What you want to do is not yet possible in V11.