Revit Tip: Symbolic vs Model-Only Geometry in Revit: Best Practices

Clarity in documentation often depends on showing different representations of the same element. In Revit, use symbolic (2D) and model-only (3D) geometry deliberately to keep views readable and coordinated.

What’s the difference?

• Symbolic geometry: View-specific lines and masking regions in families that appear in orthographic views (plan/elevation/section) but not in 3D. Ideal for door swings, schematic equipment symbols, simplified fixtures, and diagrammatic annotations.
• Model-only geometry: True 3D solids/voids and model lines that appear in all model views. Ideal for coordination, quantities, and clash detection. Control their visibility per view, detail level, and subcategory.

Why it matters

• Improves readability in plans and RCPs without overloading drawings with complex 3D edges.
• Reduces view regeneration time by showing simplified 2D at Coarse while keeping accurate 3D at Fine.
• Enforces consistent graphic standards across your office. If you source Revit via NOVEDGE, standardize these rules in your templates and family library.

Family Editor setup (recommended pattern)

• Model geometry accurately and assign meaningful Subcategories (Object Styles). This allows view templates to control visibility globally.
• Add Symbolic Lines for plan/elevation cut graphics. Use masking regions sparingly to clean up intersects.
• Control visibility by detail level (Coarse/Medium/Fine) and by view type (Plan/RCP, Elevation, 3D) in the Visibility/Graphics dialog for each element.
• Create Yes/No parameters (e.g., Show_Symbolic, Show_3D) and tie element visibility to them. This enables quick type-based switches.
• Use subcategory lineweights to differentiate symbolic graphics from model edges without per-view overrides.

In the project environment

• Prefer family-based symbolic graphics over Detail Lines drawn in views. It’s more reliable and reusable.
• Use View Templates to control subcategory visibility so symbols read properly across all sheets.
• For doors/windows: keep 3D leaf/panel model-only; show swings and clearances with symbolic lines that follow door handing and type.
• For equipment: show a clean plan symbol at Coarse, reveal connectors and precise 3D at Fine for coordination.

Quality checks before publishing

• Test each family in Plan, RCP, Elevation, Section, and 3D. Verify what appears at each detail level.
• Confirm cut-plane behavior with the family’s “Cuttable” category and view range. Adjust symbolic cut graphics as needed.
• Verify tags and schedules still read parameters correctly after visibility changes.

Performance and maintenance tips

• Keep coarse-level model geometry simple; push linework to symbolic where appropriate.
• Avoid overusing masking regions; replace with clean symbolic linework and correct subcategory weights.
• Centralize subcategories and line styles in your template. If you manage standards through NOVEDGE-supplied deployments, bake these into your office Revit template for consistency.

Common pitfalls to avoid

• 3D door swings or complex edge visibility in plan—use symbolic arcs/lines instead.
• Unassigned subcategories for symbolic lines—makes global control difficult.
• Forgetting RCP: define separate symbolic graphics for plan and ceiling plan where needed.

Adopt a “symbolic for communication, model for coordination” mindset. You’ll deliver cleaner drawings, faster views, and more predictable documentation. For licenses, add-ons, and expert guidance, check NOVEDGE.