What about grids?

[Hans_Lammerts]

I’m having a hard time to get a decent view and grip on grids in IFC.
Both my viewers fail. According to the developers house these IFC exports are quite ok really.
I’m not a hardcore coder but the lines here look ok to me.

Grids are essential in the communication when designing and building things!
It must have been part of the certification proces. Are these viewer not certified? Any other thoughts?
I didn’t try Blender, Revit yet but maybe one of those display it better and have the right properties.

#74= IFCGRIDAXIS('A',#35,.T.);
#75= IFCGRIDAXIS('B',#38,.T.);
#76= IFCGRIDAXIS('C',#41,.T.);
#77= IFCGRIDAXIS('D',#44,.T.);
#78= IFCGRIDAXIS('E',#47,.T.);
#79= IFCGRIDAXIS('1',#50,.T.);
#80= IFCGRIDAXIS('2',#53,.T.);
#81= IFCGRIDAXIS('3',#56,.T.);
#82= IFCGRIDAXIS('4',#59,.T.);
#83= IFCGRIDAXIS('5',#62,.T.);
#84= IFCGRIDAXIS('6',#65,.T.);
#85= IFCGRIDAXIS('7',#68,.T.);
#86= IFCGRIDAXIS('8',#71,.T.);

BIMGRID EXPORT IFC4.ifc (4.5 KB)
BIMGRID EXPORT IFC32.ifc (4.5 KB)

[yorik]

They import and render well down here

[Hans_Lammerts]

Looking good Yorik. Does ifcgrid have a infinite height? Still visible when you are away from where is is drawn or something.

[yorik]

FreeCAD currently doesn’t have any form of “distance-trimming/dimming” so yes, you see it from anywhere in the 3D space. But I guess what you are asking is if they extend automatically to the bounds of your view? They currently don’t, but that’s something I’d like to implement at some point, also for the working plane grid that you see underneath in the above image. Once I figure out a way to achieve that, that is

The thing is also that they have a fixed size stored in the IFC file, so it makes sense to respect that on import…

[Moult]

@Hans_Lammerts the grids are successfully imported into Blender Note that Blender doesn’t currently add the grid symbol in the 3D view (it will, however, export it into a 2D view with the grid symbol), but the data is all there. Both files work.

[Moult]

For the record, your file grids are correctly imported into Revit - it doesn’t show in 3D, but that’s just an inherent Revit thing, but it will show correctly in 2D.

[Hans_Lammerts]

Hi, i am picking up my old piece of research here. From 2015 i see ! I am not quite sure what the status is on the concencus on the academic side of gridlines, but i am still disappointed about the lack of interopability. It seem all software have a unique way of defining grid lines. That;s ok, but can we at least show them to others… To match any design in a real world 3d situation it is critical that we can rely on grids in a Country coordinat system. To see them and identify them.

The only software that was able to read grids so far… is Revit… (which has a hard time deailing with coordinats). I see a lot of fail here, sorry

BlenderBIM : no display
BricsCAD dwg : poor attributes
Navisworks : only lines
Revizto: not supported
Forge : only lines
Bimvision : looks good !! that’s the way. Only… where are the names

So I personally can’t believe a basic thing like a straight grid line was not part of any certification process. It should be, make it better.

nb.
if nobody compains (here?) that this is a standstill for ifc in the bimworld.

Edit: i added the file. It’s so simple. You could write it without CAD software on a texteditor

#32= IFCCARTESIANPOINT((-2000.,2000.));
#33= IFCCARTESIANPOINT((7000.,2000.));
#34= IFCPOLYLINE((#35,#36));
#35= IFCCARTESIANPOINT((-2000.,7000.));
#36= IFCCARTESIANPOINT((7000.,7000.));
#37= IFCPOLYLINE((#38,#39));
#38= IFCCARTESIANPOINT((0.,0.));
#39= IFCCARTESIANPOINT((0.,9000.));
#40= IFCPOLYLINE((#41,#42));
#41= IFCCARTESIANPOINT((5000.,0.));
#42= IFCCARTESIANPOINT((5000.,9000.));
#43= IFCGRIDAXIS(‘A’,#31,.T.);
#44= IFCGRIDAXIS(‘B’,#34,.T.);
#45= IFCGRIDAXIS(‘1’,#37,.T.);
#46= IFCGRIDAXIS(‘2’,#40,.T.);

BricsCAD BIMgrid.ifc (3.5 KB)

[Moult]

The file works in the BlenderBIM Add-on. Please make sure you are using the latest version of the add-on (https://blenderbim.org/) and Blender too.

There are no names because your authoring application didn’t supply names. This is a fault with BricsCAD. You will need to report it upstream as a bug to them.

[Hans_Lammerts]

The functionality in BricsCAD to make ‘IFCgrid’ is still very poor. I complained about that, i know they are actively in the proces of making ifc better. I was thinking lines #43 to #46 are the names?

On ifc import in the dwg editor the names come in as block. A, B,1,2 also come over in Bimvision en Revit (best result in definition! Well done Autodesk). Can you tell me what lines of codes are missing in the ifcexports from Bricssys Dion? I will pass it on.

[Moult]

@Hans_Lammerts an important thing to check if whether or not data is being preserved. For example, you may only see lines, but actually all the data is there. In the BlenderBIM Add-on, for example, indeed you only see lines, because that is what is defined in the IFC… however, the label, (e.g. A, B, 1, 2) is actually stored as data.

So for example, in the BlenderBIM Add-on 3D view, you only see lines, simply because that is the default style in that viewing mode (note: a future feature will be to draw labels in 3D too), but if you use the “generate drawing” mode feature in the BlenderBIM Add-on, it’ll then render out like this:

So as you can see, all the data is 100% preserved. Also, under the hood, it preserves styles on whether it is the U axis or V axis.

In contrast, Revit may “look” visually like grids, but actually it has destroyed the underlying data. For example, it has reset the name of the grid to “Default Grid”, and it has actually reversed the U axes and the V axes. In the original, UAxes are A and B, and VAxes are 1 and 2, but Revit will generate its own. The BlenderBIM Add-on preserves this in the outliner (and also supports WAxes). Note: tested with Revit 2020, latest IFC add-on. It also generates a new representation for the Grid itself (not each individual axis). In your particular example, this doesn’t matter, but in others, it will.

This data detail may not seem like much to a user who just wants to visually see results, but it is actually pretty important if we want to rely on IFC as a reliable data store.

To add to the party, FreeCAD also imports grids successfully. However, I think it has similar problems to Revit in that it will mangle the axes.

Screenshot from FreeCAD:

I think I understand now what you are looking for in BIMVision - it doesn’t show the individual axes in your screenshot. So it’s not the name that is missing (though technically, it actually is missing the name for the grid itself) - it’s actually the grid axes which are missing. Maybe someone with more experience in BIMVision can help.