Import .rvt files to bricscad

Ricardo Cruz

The .rvt file format is becoming common among construction producers and they provide bim files for architects and engineers.
I think the Bricscad BIM workflow needs to be integrated with this, otherwise we will have to model this by hand wich would become extremely time consuming...

So, does anyone know a process to import those .rvt files without using revit?

Robt Deans

.rvt files are native to Revit.
Unfortunately, there are no 3rd party converters.
You'll need to request your source to save as .dwg.

Roy Klein Gebbinck

This may be of interest:

upfrontezine.com/2016/09/oda-opens-the-revit-file-format.html: Members who want to import Revit data are already doing this now, such as Vectorworks and Bricsys.

Per Gogstad

@Ricardo Cruz said:
The .rvt file format is becoming common among construction producers and they provide bim files for architects and engineers.
I think the Bricscad BIM workflow needs to be integrated with this, otherwise we will have to model this by hand wich would become extremely time consuming...

So, does anyone know a process to import those .rvt files without using revit?

The common file format between different BIM applications is IFC. Use IFC export in Revit and then IFC import in BricsCAD. Both applications are IFC certified by buildingSMART.

Ricardo Cruz

@ Robt Deans
Thanks, that's what I was very much afraid of...

@ Roy Klein Gebbinck
WOW! that's great news! I will try teighta bim. It seams perfect to save as ifc or dwg. A big thank you for the suggestion!

@ Per Gogstad
Thanks for the feedback.
I totally agree about the importance of IFC file format. Nonetheless, window manufacturers for instance only provide .rvt files. It's stupid but we can't change the world, right? At the same time the revit license cost is something we consider abusive. Requiring manufacturers to save as different file format is also time consuming
So that leaves us with only one option: Use teighta bim trial

Ricardo Cruz

@ Roy Klein Gebbinck
I am also very optimistic knowing that Erik de Keyser, stated

" Bricsys is already working with Teigha BIM. The challenging goal we aim for is to import Revit's parametric objects (windows, doors, furniture, and so on) stored as .rfa Revit Families files, and converting them to BricsCAD BIM parametric components. (These are our 3D versions of "dynamic blocks" containing DWG solids controlled by parameters and 3D constraints.) Our goal is to make this translation possible without the need for manual interaction."

I think Erik fully understands the cad industry future and Bricscad strategy seems also to understand the market needs.

Ricardo Cruz

...But until now ... no response form teiga...

Michael Mayer

Vectorworks has a second iteration of Revit Import by Teigh Libraries.
While the first iteration just brought Meshes and exorbitant file sizes,
the second iteration brings some Walls/Roofs/Slabs/Windows/Doors in.
With different results. It looks like the way Revit joins their Objects does
not fully translate. So I get parts of roofs that look like rests of not proper
boolean operations.
And I am not sure if Revit is the "SketchUp" under BIM geometries or Teigha
translation just not yet ready.

And my other problem are Blocks like sanitary objects used in Revit are also
mostly Mesh Geometries, which no CAD really likes.
And it seems for me that is the case for mostly all available RVT library
files you find for downloads. Like e.g. BIMObject.
So no Solids geometry like "Shape" own Library Objects.

So I am not so excited with Revit Import so far as the resulting geometry is
unlikely something that I want to have in my 3D Model's files, beside
being used as a Reference only.

stefkeB

IFC scheme does support much more than only Solid geometry. Meshes (FacetedBrep) is widely used when exporting from other software, so you might get used to receiving such geometry from IFC models.

Michael Mayer

Most CADs don't do a good job dealing with Meshes.
It slows everything down and you can't do much with these.

And from a Mesh Modeler perspective which like Meshes,
those Meshes automatically generated for libraries are horrible too.
No one would Mesh Model objects from scratch in such a way.

Garbage in, garbage out ....

I don't know Revit and how it works. If there is anything Solids at all.
I am so happy that IFC supports Solids and I get even Solids into
Bricscad by IFC, from objects that weren't Solids but custom
BIM geometry.
Or I am very pleased by Shape's cute Solids Libraries

Tom Foster

As Brics' forthcoming approach to Point Cloud (which is a catch-up which has to happen) seems to be uniquely(?) linked somehow wich VR (according to the presentation at the last Brics Conference), that necessarily means that Brics will b ecome v gd at handling meshes, as VR 'environments' (other than flat-plane new-builds) are freeform mesh-based (please tell me if that's wrong).

Michael Mayer

Point clouds are in first place 3D Points with a color information,
no Meshes. So an App has to be optimized to display millions
of colored Points
Those are most often just used as a sketch or underlay to snap to
and do manually model over them.
So the next more complicated and rare but more interesting step
is to automatically generate Mesh or better Solids Geometry from
Point Clouds.
Something which is easy for humans but hard for computers and
needs some AI. But it works already well for Geometry Generation
based on Images and I think we can see a lot of progress for Point
Clouds too.

So I would not think that Point Cloud Support will automatically bring
better Mesh Support and Handling for CAD Apps by itself.
But if Mesh Geometries will come more often by IFC or Libraries like
BIMObjects, App Developers might react to this need.

Tom Foster

@Michael Mayer said:
So I would not think that Point Cloud Support will automatically bring
better Mesh Support and Handling for CAD Apps by itself.

True, but the particular, novel way that AFAIK Brics, a bit late in the day, is approaching Point Cloud enablement, is somehow via VR - and that I believe necessarily means fluency with meshes (am I wrong?). It could be a phenomenally powerful tieing-together of disparate, up-to-the-minute phenomena - a Brics-worthy out-flanking of the other players which apparently got there earlier. I hope so anyway, looking forward to October maybe?

Michael Mayer

I am not sure about VR.
VR came from Game Engines and 3D Polygon Modelers so
it is mostly Mesh based. But for a long time we have Rendering
and even openGL means converting Solids to Triangles.

Vectorworks says they have still bad Mesh support and it will slow
things down. No clue if Meshes will slow down Bricscad 3D display
or not. But for now, when I get Meshes or Faces in and I want to work
with these in any way, I try to convert or rebuild them into Solids.

Tom Foster

@Michael Mayer said:
No clue if Meshes will slow down Bricscad 3D display

That's the essence, or one of the essentials, of Point Cloud enablement - algorithms to make display rotation etc go just as fast as with a relatively 'light' vector model, when meshes and point clouds are usually extremely 'heavy'.

Don't know how pure-mesh based 3D modellers do it, but un-enabled CAD (like present Brics) simply stalls, however hot the graphics card.

I have an ancient copy of PointTools, which rotates large point clouds splendidly, with decimation (temporary drastic simplification) of the image while rotation is happening, and re-appearance of the full image when rotation stops. Bentley bought PointTools, which is now their Point Cloud engine - but rotation is not nearly as satisfactory as implimented in Microstation - 'only partial implimentation' apparently - don't know why.

I understand that decimation is done by creating ten or so different LoD versions of the model, which are deployed as necessary depending on how challenged the graphics card feels. Such decimation may be an essential part of VR, while the image is moving - maybe decimation cleverness within some VR software is that what we're seeing in this video
https://www.youtube.com/watch?v=pYGaKthb3jc&index=14&list=PLONdQc9bizsefon1FeedsK0fglNrp8uB-
from Brics Conference 2017?

Is this the fluency, with in this case a 70GB model incl Point Clouds/laser scans, that we'll be seeing on our own computer screens? As Erik says, this is showing VR from a company that Bricsys may well be buying, and I think that co was named during the Conference.

Michael Mayer

I just still think that Point Clouds are something different than Meshes.

Tom Foster

Agreed - but other point cloud enabled CADs also handle meshes better because the trick is to make 'heavy' models rotatable - whether they're meshes, point clouds or even huge vector models. Beyond that, it looks like Brics' approach will particularly major on meshes and VR, as well as point cloud. Maybe just wishful thinking!

Michael Mayer

I think there are many options to speed up Tools and Display.
How you triangulate Solids for a 3D view and how to profit from
Blocks or how to accelerate Point Clouds and how Meshes are treated.
I think RED SDK offers nearly everything you want to need and if there
is a valuable need it will be implemented and used.
For now, I am pretty amazed how fluid Vectorworks handle my 3D stuff.
If I put the export in Bricscad (Mac!) it works ok but as soon as I set my
Tree Blocks (Meshes) visible there, 3D Vieport has 1 FP10S.
That may be much better on Windows and maybe NVidia GPU, I don't know
Any improvement welcome.
On the other hands VW completely sucks if I import these Revit Files.
For me it doesn't matter if it's the importer or Revit files iteslf.

I think the possibilities are endlesss, it is about what the priorities are.