title: Implement clip= parameter in viewer.html

description: The ifc:// spec defines a repeatable clip= parameter (6 floats: point x,y,z + normal x,y,z in IFC world coords). The Python ifcurl renderer handles it, but viewer.html ignores it entirely — no parsing, no Three.js clipping planes, no round-trip into the URL on camera sync. Implement: parse clip= from the ifc:// URL, apply as THREE.Plane clipping planes to the renderer (with IFC→Three.js coordinate transform), and include current clip planes when rebuilding the URL.

status: open

issue_type: feature

created_by: Bruno Postle


title: viewer.html: structured form UI for ifc:// URL components

description: Replace the single ifc:// URL text input with individual labelled fields for each component: host/repository, ref (branch/tag/commit), path (file within repo), selector (IfcOpenShell selector), camera, fov/scale. Editing any field should update the ifc:// URL and reload the model. The raw ifc:// URL should still be visible/copyable. This makes the viewer usable without needing to hand-edit a URL string.

status: closed

assignee: Bruno Postle

close_reason: Structured form UI implemented with repo/ref/path/selector fields; crash recovered, changes committed.


title: viewer.html: FOV control and restore fov=/scale= from URL

description: Two gaps: (1) No UI to change the camera FOV — add a control (e.g. a small number input or slider in the toolbar) so the user can adjust perspective FOV or orthographic scale. (2) applyCameraParam reads position/direction but ignores the fov= and scale= params written by syncCameraUrl — restore these when placing camera from URL so a shared link opens at exactly the recorded viewpoint.

close_reason: Closed


title: viewer.html: implement ifc:// selector= parameter

description: The ifc:// URL spec supports a selector= param using IfcOpenShell selector syntax (e.g. selector=IfcWall, selector=IfcSlab.Name='Floor'). The viewer currently ignores it. Implement selector filtering in the browser: parse the selector= value, query matching elements from the loaded FragmentsModel, and apply highlight/isolate/ghost visibility to them. @thatopen/components has Highlighter and Hider components that may be usable. The selector syntax used is the IfcOpenShell Python selector syntax — a JS port or subset may be needed.

notes: Selector syntax docs: https://docs.ifcopenshell.org/ifcopenshell-python/selector_syntax.html — Python implementation in ifcopenshell.util.selector module. Need a JS port or subset. Syntax includes: IfcType, .Attribute='value', #GlobalId, [pset.prop], boolean operators (+ for union, , for intersection within group).

close_reason: applySelector() implemented: byCategory classification + prefix subtype matching + hider.isolate(). Supports simple type names and + union. Attribute filters noted as future work.


title: viewer.html: generalise toRawUrl() to support GitHub, GitLab etc.

description: toRawUrl() currently only handles Forgejo/Gitea HTTPS URLs, mapping ifc://host/org/repo@hash?path=file to http(s)://host/org/repo/raw/commit/hash/file. This needs to: (1) detect the git host type and construct the correct raw file URL — GitHub → raw.githubusercontent.com/org/repo/hash/file; GitLab → host/org/repo/-/raw/hash/file; Forgejo/Gitea → host/org/repo/raw/commit/hash/file; (2) handle SSH ifc:// URLs (user@host form per the spec) by stripping the user@ prefix and rewriting to HTTPS for browser fetching — ifc://git@github.com/org/repo@hash becomes https://raw.githubusercontent.com/org/repo/hash/file.


title: viewer.html: place camera from ifc:// URL camera= param on load

description: When viewer.html loads with a camera= param in the ifc:// URL (9 comma-separated floats: position, direction, up in IFC world coordinates), apply the IFC→Three.js coordinate transform (Y/Z swap, one negated) and set the Three.js camera position, direction and up vector accordingly. Depends on the syncCameraUrl fix (ifcurl-j2s) so the forward and inverse transforms are consistent.

type: blocks


title: viewer.html: URL input box and drag-and-drop target

description: Add a text entry box and a drag-and-drop target to viewer.html so any ifc:// URL can be loaded without navigating from a Forgejo page. The input should accept a pasted ifc:// URL and immediately load it into the viewer. Drag-and-drop should accept a dropped ifc:// URL or a .ifc file URL. This makes the viewer usable as a standalone tool.


title: Apply forward IFC→Three.js transform when setting camera from URL params

description: When the viewer page loads with a camera= param in the ifc:// URL, the 9 floats are in IFC world coordinates. Apply the IFC→Three.js transform to convert them before passing them to the Three.js camera / camera-controls. This is the forward direction of the same transform used in the inverse task.

issue_type: bug

issue_id: ifcurl-cmd

depends_on_id: ifcurl-ldk


title: Apply inverse IFC↔Three.js transform in syncCameraUrl

description: Using the transform found in the research task, apply its inverse to camera.position, the direction vector, and camera.up before serialising them as the ifc:// camera param in syncCameraUrl. The result should be in IFC world coordinates (Z-up, matching BCF viewpoint conventions) not Three.js scene space.


title: Find IFC↔Three.js coordinate transform in @thatopen/components source

description: Grep ~/src/engine_components and ~/src/engine_fragment for the matrix or transform applied when an IFC model is loaded into Three.js scene space. IFC uses Z-up; Three.js uses Y-up. @thatopen/components almost certainly applies a 90° X-axis rotation (and possibly a scale) when constructing the Three.Group from IFC geometry. Record the exact transform so the inverse can be applied in syncCameraUrl.

issue_type: task

close_reason: Transform identified: IFC→Three.js is a Y/Z swap with one axis negated (Z-up to Y-up). Unblocks j2s and cmd.


title: Deploy footer.tmpl to Forgejo custom templates directory

description: Copy forgejo/templates/custom/footer.tmpl from the repo to /etc/forgejo/templates/custom/footer.tmpl on the Forgejo server. No Forgejo restart needed — custom templates are loaded dynamically. Verify the View in 3D button appears on an .ifc file page.

depends_on_id: ifcurl-ohq


title: Update footer.tmpl: point viewer button to Forgejo static file URL

description: Change the VIEWER_BASE URL in forgejo/templates/custom/footer.tmpl from http://localhost:8000/viewer to the Forgejo static file URL determined by the research task (ifcurl-5t3). The button href should become something like /assets/viewer.html?url=ifc://... rather than the ifcurl service URL.

issue_id: ifcurl-ohq


title: Deploy viewer.html to Forgejo server

description: Copy the viewer static file from the repo to the correct location on the Forgejo server so it is served at its expected URL. Document the deployment step in the repo (e.g. Makefile target or install notes).


title: Remove /viewer and /proxy endpoints from service.py

description: Once the viewer HTML is served as a Forgejo static file and fetches IFC bytes directly from Forgejo (using the browser session for auth), the /viewer and /proxy endpoints in ifcurl/service.py are defunct. Remove them and clean up the associated VIEWER_HTML constant in viewer.py.

issue_id: ifcurl-cuh


title: Move viewer HTML to Forgejo custom static file

description: Extract the VIEWER_HTML constant from ifcurl/viewer.py and write it as a static HTML file in the repo under the Forgejo custom static directory (path determined by the research task). The file should be a standalone page — no dependency on the ifcurl service for serving.


title: Research Forgejo custom static file serving

description: Determine where Forgejo looks for custom static files and what URL they get served at. Check the Forgejo docs and source for the custom/ static directory convention. The result feeds into the viewer HTML deployment and the footer.tmpl URL update.

notes: Forgejo serves custom static files from <CustomPath>/public/assets/ at URL /assets/*. CustomPath is /var/lib/forgejo/custom on this system. No auth required. Any file type. Place viewer.html at /var/lib/forgejo/custom/public/assets/viewer.html → served at /assets/viewer.html.


title: Forgejo goldmark extension: handle bare ifc:// URLs in markdown

description: The goldmark extension in the patched Forgejo binary (modules/markup/markdown/ifc_url.go) currently only detects ifc:// URLs when written in explicit markdown link form [Title](ifc://...). It should also auto-link bare ifc:// URLs pasted inline in markdown text, the same way goldmark auto-links http:// URLs. Extend the extension (or add a separate autolink pass) to detect raw ifc:// URL tokens and wrap them in the preview embed.


title: Serve viewer HTML as Forgejo static files instead of ifcurl /viewer endpoint

description: Currently the viewer is served from the ifcurl preview service at GET /viewer, and IFC bytes are fetched via GET /proxy to work around CORS. This has two problems: it pipes all IFC data through the ifcurl service (bandwidth/latency), and it bypasses the browser's existing Forgejo authentication (cookies/session) so private repos won't work. Better architecture: deploy the viewer HTML as a Forgejo custom static file (e.g. /assets/viewer.html or via a custom template). The viewer JS can then fetch IFC bytes directly from Forgejo's raw file URL using the browser's existing session, so auth is inherited automatically and no proxy is needed. The /viewer and /proxy endpoints in ifcurl/service.py can be removed once this is working.

close_reason: Split into atomic tasks: ifcurl-5t3, ifcurl-55f, ifcurl-cuh, ifcurl-4yu


title: Fix syncCameraUrl: convert WebGL coords to IFC world space

description: syncCameraUrl in viewer.py currently records camera.position/direction/up directly from Three.js, which are in WebGL/Three.js coordinate space (Y-up, different scale/orientation than IFC). The ifc:// URL spec expects IFC world coordinates (Z-up, matching BCF viewpoint conventions). Need to find the IFC→Three.js transform that @thatopen/components applies when loading a model, then apply its inverse in syncCameraUrl before serialising the camera params. Repos cloned for reference: ~/src/engine_components and ~/src/engine_fragment.

close_reason: Split into atomic tasks: ifcurl-ldk, ifcurl-j2s, ifcurl-cmd


title: Test Phase 3b web viewer end-to-end

description: After deploying the footer template (ifcurl-ach), test the full flow: open an .ifc file in Forgejo at localhost:3000, click 'View in 3D', verify the viewer loads the model. CDN versions (@thatopen/components 2.4.0, three 0.160.0, web-ifc 0.0.66) may need adjustment if the API has changed.

depends_on_id: ifcurl-ach

depends_on_id: ifcurl-ahd


title: Deploy Phase 3b footer template to Forgejo

description: The footer.tmpl file that injects a 'View in 3D' button on .ifc file pages has been written but not yet deployed. Deploy it to /etc/forgejo/templates/custom/footer.tmpl and verify the button appears when viewing an .ifc file on localhost:3000.

close_reason: Split into atomic tasks: ifcurl-ohq, ifcurl-49o

issue_id: ifcurl-ach


title: viewer.html: interactive tool to set clipping planes

description: Currently clip= planes can only be set by hand-editing the URL. Add an interactive clipping tool to the viewer: a UI control (e.g. toolbar button) that lets the user drag/place a clipping plane against the loaded model. The plane position and normal should be written back into the ifc:// URL as clip= parameters so the view is shareable. Consider using ThatOpen's clipper component (OBC.Clipper) if available, or a Three.js-based approach.


title: Cache size control for bare repo clones

description: git.py clones remote repos as bare repos under ~/.cache/ifcurl/<hash>/repo.git with no size limit or eviction policy. Large repos accumulate indefinitely. Add a configurable max cache size (e.g. via env var IFCURL_CACHE_MAX_GB or a config file) with an LRU eviction policy based on last-access time of each repo directory. Should also expose a CLI command (ifcurl cache --list, --prune, --clear) to inspect and manage the cache manually.


title: Assess Go test strategy for Forgejo plugin patch

description: The Forgejo integration is a low-maintenance source patch (footer.tmpl, viewer.html, /viewer and /proxy HTTP handlers). Evaluate whether adding Go tests is feasible without coupling to Forgejo's full test suite: can the handler logic be extracted into a small testable package, or do tests have to live inside the Forgejo tree? If the cost of keeping tests green across Forgejo upstream upgrades is too high, document the decision and close. Outcome: either a small test file or a documented rationale for no Go tests.


title: Add JavaScript tests for viewer.html URL logic

description: viewer.html contains pure-JS functions (parseIfcUrl, buildIfcUrl, toRawUrl, syncCameraUrl) with no test coverage. Add a lightweight JS test harness (e.g. a standalone test.html or Node-runnable test.js using the native test runner) that unit-tests these functions: round-trip URL parse/build, toRawUrl for each host type (GitHub, GitLab, Forgejo), and camera parameter serialisation. No browser automation needed — pure function tests.


title: Audit and extend Python test coverage

description: 103 tests exist across test_url.py, test_git.py, test_auth.py, test_render.py, and test_service.py. Audit what is missing: check branch/edge coverage in git.py (offline fallback, mutable ref fetch, auth injection), service.py (tier 2 cache eviction, mutable ref bypass), and the CLI entry points in __main__.py. Add tests for any significant gaps found.


title: Phase 4: Bonsai IFCDOCUMENTREFERENCE federation via ifc://

description: When opening a model via ifc://, resolve IFCDOCUMENTREFERENCE locations using the repo and ref from the root file's URL as context. Resolve ifc:// locations in linked model references recursively. Requires the Phase 4 protocol handler (ifcurl-0oj).

status: deferred

issue_id: ifcurl-bqt


title: Phase 4: Bonsai 'Copy view URL' button

description: Add a button to Bonsai that generates an ifc:// URL from the current state: git remote/ref/file path, active selection as IfcOpenShell selector, current camera as camera+fov or scale params in IFC world coordinates, active clipping planes as clip params, current visibility mode. Default to commit hash ref; secondary option for @heads/ ref.

issue_id: ifcurl-lcr


title: Phase 4: Bonsai ifc:// OS protocol handler

description: Register ifc:// as an OS protocol handler in Bonsai on installation (Windows, macOS, Linux). On receiving a URL, resolve the git source, load the model, and apply the view state from the URL parameters (camera, selector, clipping planes, visibility mode). This is the foundation for all other Phase 4 work.


title: Phase 3c: Verify Forgejo merge-ability check works with ifcmerge

description: Investigate whether Forgejo's merge-ability check (the 'branches can be merged automatically' indicator) correctly reflects ifcmerge's ability to handle .ifc files. Determine if Forgejo runs a trial git merge or uses a heuristic. If needed, patch Forgejo to run a trial git merge --no-commit to get an accurate result.

issue_id: ifcurl-cyw


title: Phase 3c: Register ifcmerge as git merge driver on Forgejo server

description: Configure ifcmerge as the git merge driver for .ifc files on the Forgejo server. Add to /etc/gitconfig or ~forgejo/.gitconfig: [merge "ifcmerge"] name = IFC merge driver / driver = ifcmerge %O %A %B %L. Add *.ifc merge=ifcmerge to server-side gitattributes. This allows Forgejo's 'merge automatically' path to invoke ifcmerge via git when merging .ifc files.

author: Bruno Postle

text: ifcmerge needs to be installed as a pair of merge tools because the merge process is asymmetrical and we need to be able to prefer one branch over another (because step-ids from one branch get rewritten in the merged file). In practice we prefer origin and/or main/master branches. there is code in the ifcopenshell bonsai ifcgit module for reference.


title: Future: Contribute ifc:// URL parsing to IfcOpenShell

description: Once the Python core URL parsing and resolution logic is stable, contribute it to IfcOpenShell as a shared utility. Not a prerequisite for any phase — pursue after Phase 1 has been stable in production use for a while.


title: Future: BCF export endpoint /bcf

description: Add a /bcf endpoint to the preview service: POST /bcf with body {url: 'ifc://...'} returns a BCF zip file. Resolve the selector to a GUID set and construct a BCF viewpoint from the camera, clipping planes, and visibility state. Not planned before Phase 2 is complete.


title: Phase 6: Bonsai offer ifc:// URL when saving linked model reference

description: When saving an IFCDOCUMENTREFERENCE in Bonsai, offer the option to write the location as an ifc:// URL rather than a relative path. When a relative path would traverse above the repository root, prompt the user to convert it to an ifc:// URL. Requires Phase 4 federation (ifcurl-bqt).

issue_id: ifcurl-vam

depends_on_id: ifcurl-bqt


title: Phase 5: IFC Viewer integration (equivalent of Phase 4)

description: Add ifc:// OS protocol handler and 'Copy view URL' button to the IFC Viewer desktop application, equivalent to the Bonsai Phase 4 integration. Depends on Phase 4 being complete as a reference implementation.


title: Phase 3c: 3D diff view for IFC PR merges

description: After a PR merge completes, surface a 'View merge in 3D' button using the Phase 3b viewer. Use @thatopen/components highlighter to colour added, removed, and modified elements differently, driven by comparing the merged IFC against either parent. Requires Phase 3b viewer (ifcurl-i1s) to be working.

issue_id: ifcurl-prc


_type: memory

value: Forgejo build and deploy procedure: go build -C /home/bruno/src/forgejo -tags 'sqlite sqlite_unlock_notify' -ldflags "-X 'forgejo.org/modules/setting.StaticRootPath=/usr/share/forgejo'" -o /home/bruno/src/forgejo/forgejo . — then sudo cp forgejo /usr/bin/forgejo. StaticRootPath=/usr/share/forgejo. CustomPath=/var/lib/forgejo/custom. Custom templates go to /var/lib/forgejo/custom/templates/custom/ (e.g. footer.tmpl → /var/lib/forgejo/custom/templates/custom/footer.tmpl). Custom static files go to /etc/forgejo/public/assets/ and are served at /assets/*. /var/lib/forgejo is root/forgejo-only. /etc/forgejo has conf/ public/ templates/ but only public/assets/ is used for static files.