7 min read Updated May 2026

Thumb Gen Documentation

Complete guide to installing, configuring, and using Thumb Gen to standardise every Revit family thumbnail in your library.

Supported Revit Versions

• Revit 2022
• Revit 2023
• Revit 2024
• Revit 2025
• Revit 2026
• Revit 2027

Installation

Quick Start

Follow these steps to refresh your first family thumbnail:

Open Thumb Gen

With a family document (.rfa) open in the Family Editor, go to the Add-Ins tab and click Thumb Gen on the AUTOM8LABS panel. The main dialog opens with two tabs - Home and Settings. The button is enabled only inside the Family Editor - it stays disabled for project documents.

Set the Default Appearance

On the Home tab, the 3D Default and 2D Default rows cover the active family's category. Set the View, Visual Style, Detail, and Scale every family should use, or add an override row for specific categories.

Apply to the Active Family

Click Apply. Thumb Gen builds the thumbnail view, hides annotation elements, marks the view as the family preview, and saves the .rfa.

Batch a Whole Folder

Point Batch Folder at a library of .rfa files to classify and process every family unattended, with Pause, Resume, and Cancel mid-run. Batch Folder is a licensed feature.

Home Tab

The Home tab - Generate Family Thumbnails - is where you configure how every family in your library should look. It exposes two grids - a Default Appearance grid and a Default Appearance Override grid.

Default Appearance grid

Two rows that always exist - 3D Default and 2D Default. Every family that doesn't match an override row uses these.

• 3D Default - applies to every 3D-categorised family (Casework, Columns, Doors, Furniture, Mechanical Equipment, Plumbing Fixtures, Lighting Fixtures, Generic Models, etc.)
• 2D Default - applies to every 2D-categorised family (Detail Components, Generic Annotations, Title Blocks)

Each row exposes four cells - VIEW, VISUAL STYLE, DETAIL, SCALE:

Cell	3D row options	2D row options
VIEW	Top, Front, Right · Top, Front, Left · Top, Back, Right · Top, Back, Left	Floor Plan (only valid option for 2D family editors)
VISUAL STYLE	Wireframe · Hidden Line · Shaded · Shaded with Edges · Consistent Colors · Realistic · Realistic with Edges · Ray Trace	Same set
DETAIL	Coarse · Medium · Fine	Same set
SCALE	35 scale denominators - Metric (1:1 to 1:5000) followed by Imperial (12"=1'-0" to 1"=100'-0")	Same set

The View dropdown is context-aware per row - 2D rows never offer 3D isometric options because a 2D family editor has no isometric or elevation view to render.

Default Appearance Override grid

Per-category overrides. Each row targets a list of Revit categories - whenever a family belonging to one of those categories is processed, the override's View / Visual Style / Detail / Scale wins over the matching default row.

• Click the + button to add a row
• Click the CATEGORIES cell to open the category picker
• The row's View dropdown automatically reclassifies based on what you pick - all selected categories classify as 2D → row flips to 2D mode (Floor Plan only); any 3D, Truss, Rebar, or unrecognised category → row stays in 3D mode (four isometric options)
• The − button removes the selected row

Settings Tab

The Settings tab holds five cards - Appearance, Hide Elements, Output, View Name, and Shared Settings. Every option persists to disk on change.

Appearance

• Enable gradient backgrounds - applies a gradient sky background to 3D views
• Enable 'Preview Visibility' option - toggles Revit's preview-family-visibility flag on the generated view, so geometry hidden in the family is still rendered in the preview
• Smooth lines with anti-aliasing - enables View3D.SmoothEdges on isometric thumbnails

Hide Elements

Thirteen visibility toggles. Each one hides the corresponding category in the generated thumbnail view only - the family geometry itself is never modified.

Left column	Right column
Hide dimensions	Hide flip controls
Hide reference planes	Hide room calculation points
Hide reference lines	Hide host elements
Hide reference points	Hide connector elements
Hide text notes	Hide void elements
Hide invisible lines	Hide light sources
	Hide imported elements (.dwg, etc.)

Output

• Export thumbnail as PNG next to the family file - writes <FamilyName> - <View>.png alongside the .rfa
• Use square aspect ratio for exported PNG - post-processes the export onto a square white canvas at the configured resolution. Useful for content-library systems that expect square thumbnails
• Resolution (px) - 256 · 512 · 1024 · 2048. Long-edge pixel count drives Revit's ImageExportOptions.PixelSize and the square-canvas dimension

View Name

The name given to the dedicated thumbnail view stored inside each family document. Default: Thumbnail.

If a view with the chosen name already exists in the family and is compatible with the family's category (a View3D for 3D families, a non-3D view for 2D / annotation / truss families), Thumb Gen reuses it in place. Orientation, display style, detail level, scale, and visibility flags are all reapplied to that existing view. No _1 / _2 suffix sprawl. If the existing same-named view is the wrong type for the category, Thumb Gen deletes it (when permitted) and creates a fresh view - if delete is refused, it falls back to a suffixed name as a last resort.

Shared Settings

Point Thumb Gen at a network folder (UNC or mapped drive) holding a firm-wide thumbgen-settings.json. The first time you browse to an empty folder, your current local settings are pushed up to seed the firm file. The next user who browses to the same folder pulls the firm settings down. Every subsequent change writes to both the local cache and the shared folder.

• Local cache always wins offline - if the network share is unreachable, the on-save thumbnail refresh and dialog continue to work with the last-known settings
• Last-write-wins concurrency - suitable for small / medium AEC firms. If two users save settings within the same second, the later write replaces the earlier one

Batch Folder

Click Batch Folder in the footer to open a separate dialog that processes every .rfa file in a folder. This is a licensed feature - see the product page for plans.

Configuration

• Source - folder of family files to process. Optionally include subfolders.
• Output - overwrite the original .rfa files, or save the updated families into a separate output folder (originals untouched).
• Log - per-file status (success / skipped / failed) with the message returned by the updater.

Progress dialog

When the batch starts, a separate progress dialog pops out with a live cyan progress bar (X of N), the current file name, and three buttons:

• Pause / Resume - flips a ManualResetEventSlim gate the batch loop waits on between files. The WPF dispatcher is pumped on a 50 ms tick while paused so the buttons stay clickable. Pause and Resume take effect at the next file boundary (current file always finishes cleanly).
• Cancel - flips the CancellationToken. Like Pause, takes effect at the next file boundary.

Each family is opened in a background document, classified, processed through the full pipeline, and saved. Families saved in older Revit versions trigger an upgrade-confirmation dialog before processing - uncheck any you don't want upgraded and they will be skipped.

Family Categories

Thumb Gen classifies every family into one of five buckets and runs the matching view pipeline.

Category bucket	Examples	View pipeline
3D	Casework, Columns, Doors, Furniture, Generic Models, Lighting Fixtures, Mechanical Equipment, Parking, Planting, Plumbing Fixtures, Structural Columns, Windows, etc.	View3D.CreateIsometric
2D / Annotation	Detail Components, Generic Annotations, Title Blocks	Duplicate FloorPlan view + hide annotation categories
Truss	Structural Truss	Isometric with truss-specific display-style guard
Rebar	Rebar, Rebar Shapes, Area Reinforcement, Path Reinforcement	Reuses an existing valid preview view
Unknown / model fallback	Third-party model categories	Treated as 3D

Categories not explicitly enumerated fall through to CategoryType.Model → 3D, or CategoryType.Annotation → 2D. 14 family-category buckets are supported in total.

Frequently Asked Questions

Changelog