Why it matters
This article teaches one of the strongest ExyViewer review patterns without turning classification into a sales paragraph.
Section 1
The matrix is not a scoping strategy
A clash matrix is useful for deciding which entity pairs deserve checking. It is not a substitute for deciding which part of the model should be in scope at all.
Rail projects make this obvious. A track package, platform package, and cable route package can share the same spatial zone while still belonging to very different review questions.
Section 2
Why classification belongs first
Classification lets the team build a reusable logic layer before the run starts. You can separate permanent works from temporary works, isolate only platform edge assets, or define a corridor subset that actually relates to this week’s review.
Once that scope exists, the matrix becomes smaller and more meaningful. Instead of checking everything against everything, you are checking the right things against the right things.
Section 3
Where ExyViewer fits
The useful pattern is classification first, clash matrix second. In ExyViewer, that means building the scope with classification, then configuring clash detection around that defined scope rather than hoping the matrix alone will clean the result.
- Use classification to shape the review boundary
- Use the matrix to refine the check logic inside that boundary
- Export only the clash set that still matters after review
Section 4
The tradeoff
This does add one more setup step. But that is still cheaper than reviewing a report full of combinations the project never intended to discuss.
Practical takeaways
- Classification defines scope. The matrix refines scope.
- Railway federations benefit from reusable classification logic more than one-off brute-force clash runs.
- A smaller clash set is not less rigorous if the scope is better defined.
Reality check
- Classification logic still needs governance. If different coordinators define scope differently, report comparability drops.
Related commands and features
Classification, Clash Detection
Connect classification scope to IFC review
Use the IFC viewer guide to connect classification, property inspection, visibility control, and model review before downstream reporting.
Read IFC viewer guide
