Editing a model¶

Bimble edits its own .bimble models. IFC files open for viewing, plans and comparison, but are not edited: see Questions.

Every change can be undone, and an element keeps its GlobalId through every edit, so the history and comparisons know it is the same element.

To try it on a small model:

bimble demo frame.bimble
bimble view frame.bimble

With a .bimble model open, the top row's Undo, Redo and Save work, the Model tab places elements, and Manage → History keeps versions.

Change an element¶

Click an element, in a 3D view, a plan or a section. The properties panel, at the bottom left, shows its properties:

• Name;
• GlobalId, storey, material and generator, for information;
• its sizes, such as width, depth and height for a column, or length and thickness for a wall;
• Origin X / Y / Z: where it is placed, in mm. Z is relative to its storey's level.

Type a value or drag it. The change is applied when you leave the field or release the mouse: one drag is one step to undo. A size that makes no sense, such as a negative height, is refused with a message.

Move, copy, delete¶

Under the properties, Vector is a displacement in mm (X, Y, Z), 1000 mm along X to start with.

• Move moves the element by the vector.
• Copy makes a copy moved by the vector, named like the original with " (2)" added, and selects it.
• Delete, or the Del key, deletes the selected element.

Place new elements¶

In the Model tab:

1. Click Column, Beam, Wall or Slab. The button stays pressed while you place, and the properties panel shows what you place.
2. There, choose the storey.
3. Set the sizes: column section, beam width and height, wall or slab thickness.
4. Click in the view on the storey's level:
   • Column: one click, at its centre;
   • Beam and Wall: two clicks, the start and the end of its axis;
   • Slab: two clicks, two opposite corners of a rectangle.

A click snaps, within 12 pixels, to what is near, strongest first:

1. a crossing of grid axes, a column centre, a corner of an element;
2. else a grid axis or an element edge (the point slides along it, rounded to 10 mm);
3. else nothing: the point is rounded to 10 mm.

A marker under the pointer shows the point and what it snapped to ("column centre · 6000, 5000"). Hold Shift not to snap. Grid axes come from the model, or, when it has none, through its columns. Esc stops placing.

Where new elements go:

• Columns and walls stand on the storey level and are as high as the storey.
• Beams and slabs hang from the level above: their tops are flush with it.
• New elements are named P1, P2… (columns), B… (beams), M… (walls), D… (slabs). They are made of the model's concrete, which is added if the model has none.

Undo, redo, save¶

Save shows Save* when there are changes not saved. In a browser, saving downloads the model.

From the command line¶

bimble ls frame.bimble --class IfcBeam             # GlobalId, class, name, sizes
bimble set frame.bimble <GlobalId> height=600 -o frame2.bimble
bimble diff frame.bimble frame2.bimble             # what changed, element by element
bimble export-ifc frame2.bimble frame2.ifc         # IFC4, for other software

Editing an IFC file¶

You can't edit an IFC file in place, but you can convert it into an editable .bimble model:

bimble import-ifc architect.ifc architect.bimble   # IFC → editable .bimble

Every element with a shape comes along. The elements keep their GlobalIds, storeys and materials, so anything you change can be exported back to IFC4 (bimble export-ifc) and still matches the original.

• Columns, beams, walls, slabs and footings with rectangular sections become parametric elements you can resize in the viewer; other shapes of these classes become polygon or mesh elements, which you can move and rename but not resize yet.
• Every other element (doors, windows, pipes, fittings, ducts, equipment…) becomes an IfcBuildingElementProxy that keeps its own IFC class name, shown wherever a class is shown. You can select it, move it, give it properties and version it, not resize it. Exported to IFC, it is written as a proxy with its class in ObjectType, and importing that file again gives the class back.
• Openings (IfcOpeningElement) are kept on the element and cut out of the mesh, and property sets are imported as text values.

In the viewer:

• File → Import IFC… picks an IFC and makes an editable .bimble copy next to it, with the same name; Ctrl+S writes that copy.
• File → Convert to .bimble (editable)… does the same for the IFC that is open. Its tooltip says how many elements become editable by dimensions.

The .bimble file¶

A .bimble file is binary and compressed: typically 17 times smaller than the IFC it came from (5 to 46 times on the models measured). A shape that repeats (a sprinkler head, a bolt, a fitting) is stored once. Files written by Bimble 0.11 and older, which were JSON text, still open.

To read a model as text, or check it with other tools, write it to a name ending in .json: bimble import-ifc model.ifc model.json, or bimble set … -o model.json.