A 3D model inside Power BI: four routes, one join

A plant model shows where things are. A Power BI report shows how they are doing. Click a pump on the model and the report filters to that pump; colour every object by its status and the model becomes the report. Try it on the toy plant below, then see how it is built.

01The pipeline

Whatever the 3D tool, the same five steps carry the model into a report. The one that decides success is step 3.

02The one idea: the tag is the join

A 3D file knows objects by an internal ID. Your trackers know equipment by tag. Power BI needs a table that maps one to the other, then every status table joins on the tag.

Three rules make the join hold:

• Keep the name at export. In glTF 2.0 (GLB is its binary form) every node carries a name and an optional extras object. Write the tag there. In IFC, each object has a GlobalId; keep a table from it to the tag.
• Extract the table with a script, never by hand. Walk the exported nodes, write ElementID, Tag to a CSV, load it as the Elements table. Re-run it on every new export.
• Count the orphans. Objects with no tag (pipe supports, steel) stay grey. Tags with no object are equipment missing from the model. Both lists belong on a QA page.

The colour is one DAX measure the visual reads per object:

Status Colour =
VAR held  = CALCULATE ( COUNTROWS ( Holds ) ) > 0
VAR punch = CALCULATE ( COUNTROWS ( Punch ), Punch[Open?] = TRUE () ) > 0
VAR done  = SELECTEDVALUE ( Status[Stage] ) = "Complete"
RETURN
    SWITCH ( TRUE (),
        held,  "#8B1E1E",
        punch, "#C08A2E",
        done,  "#2E6E4E",
        "#B9B6AE" )

03Under the hood: how a click finds its row

A GLB does not keep one mesh per pump. To draw fast, the export merges thousands of objects into a few large meshes, one per discipline and colour for example. So the object's identity travels at the smallest level there is: every vertex carries a number, the row of the tag table it belongs to. Call that number the ElementID.

vertex  POSITION (x, y, z)   _TAG
 #0     (-2.0, 1.5, 0.0)      4
 #1     ( 1.0, 1.5, 0.0)      4
 ...
 #12    ( 1.6, 2.2, 0.6)      7

The same table also says where each object sits: a box, given by its lowest and highest corner (X, Y, Z min and max) in metres. Those numbers are small on purpose. GLB stores positions as 32-bit floats, which keep about seven significant digits: at 500,000 m from zero the step between two storable values is about 3 cm, enough to make edges shimmer. So the export subtracts one point, the station origin, and measures heights from grade. Add them back to get plant coordinates.

How many triangles that GLB should keep, and how to shrink it from megabytes to kilobytes without losing a tag, is measured step by step in How heavy should a 3D model be?

04Four routes, what each can and cannot do

Two platform limits apply to every visual in routes 1 to 3. A visual reaches the web only if it declares a WebAccess privilege and your admin allows it. A visual receives data in windows of up to 30,000 rows and can fetch more, up to 1,048,576 rows or 100 MB: enough for a tag table, tight for a full model's element list.

05Which route for which need