BIM puts the design model beside what was actually built. Same position, same direction, one pane each — so “is it where the drawing says” becomes something you look at rather than measure.
Opening it
Click BIM in the tool rail. The capture stays on the left and the model loads on the right; while it is loading the pane says so. The model file’s name is in the pane header.
BIM works against the aerial model too, which is the fastest way to check a whole building rather than one room.
Choosing what the model shows
Model Structure lists every layer in the model as a searchable tree. Each row is one file — architectural, concrete, electrical, mechanical, plumbing, and so on — with the number of elements in it and an eye icon that turns it on and off.
This is how you cut a model down to the trade you care about. Turning everything off except the mechanical layers makes a ceiling comparison legible in a way the full model never is.
Looking at one element
Click an element in the model and Properties shows what the model knows about it — its identifier, name and type.
Cutting the model open
The BIM pane can be clipped: Add X Plane, Add Y Plane, Add Z Plane or Add Box. A plane slices the model along one axis; a box confines it to a region. Use it to get inside a floor without hiding it layer by layer.
Overlaying instead of splitting
TwinLens works here as it does in date compare — the model drawn over the capture with a slider, rather than beside it. For checking whether something is in the right place, overlay usually reads better than side by side.
Performance, when a model is large
The BIM pane has its own settings, grouped as Configuration, Navigation and Appearance. The ones that matter on a heavy model are under Performance Optimization — disabling shadows, progressive display, and a target frame rate. If the model is slow to move, start there.
When the model will not load
A DWG-backed view can report that the DWG viewer is not connected. That is a session that has not started rather than a broken file — the message says what to do.