GitHub Repository

Overlay web map tiles (OSM, aerial, custom XYZ) onto Autodesk APS Viewer as a camera-synced 3D ground plane. Handles coordinate transforms, frustum calculation, tile stitching, and caching.

12 starsJavaScript

Overlay map tiles onto Autodesk's 3D BIM Viewer

Name: Overlay map tiles onto Autodesk's 3D BIM Viewer
Availability: InStock
Author: gubets

by gubets·Mar 24, 2026·4 points·0 comments

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AI Analysis

●●SolidNiche GemBig Brain

Coordinate transform pipeline from Revit to WGS84 that Autodesk's own viewer doesn't provide.

Strengths

•Five-step coordinate pipeline handles CRS, feet-to-meters, and BIM refPointTransform correctly.
•Frustum ray-casting with debounced camera updates prevents excessive tile fetches.
•Single peer dependency (proj4) keeps the ~500-line codebase lightweight and auditable.

Weaknesses

•Extremely narrow audience—only matters if you're already using Autodesk APS for infrastructure BIM.
•No fallback for models without proper georeferencing metadata, which many Revit exports lack.

Post Description

https://github.com/infra-plan/bim-tile-overlay

We manage infrastructure using BIM models in Autodesk Viewer. We needed to show aerial imagery and street maps underneath the 3D models, synced to the camera in real-time, so that we can give some context to the shown infrastructure.

The hard part: coordinate transforms. A Revit model's internal coordinates are in feet, rotated, translated, and offset from a local CRS projection, which itself needs to be converted from WGS84. The library ray-casts the camera frustum onto a ground plane, converts the hit points to lon/lat, determines which XYZ tiles to fetch, stitches them into a canvas, and maps the result onto a THREE.js plane, all updating on camera change. ~500 lines of JavaScript, MIT license, one peer dependency (proj4).

We would love to hear community feedback! The reason we decided to open-source is quite common: we couldn't find something similar to this that would not require a significant change to our workflow.

Hope others will find benefit from this library.