Explicit templates file management by nicolas-lambert-tc · Pull Request #3153 · alicevision/Meshroom

nicolas-lambert-tc · 2026-06-30T14:04:15Z

Description

This PR makes Meshroom template files explicit in the project flow. Templates can now be detected from their file extension or serialized header, opened through a dedicated template flow, tracked in their own recent-files list, and clearly identified in the GraphEditor when an opened graph comes from a template.

Features list

Add the ".mgt" extension to explicitly represent template files
Old templates files (".mg" with template:true) are still loadable
Display a visible GraphEditor indicator when the current graph was opened from a template.

Implementation remarks

Template detection is centralized in meshroom.core.files so both core and UI code use the same rules.
Opening a template still initializes an unsaved graph, but the source template filepath is stored separately on the graph model for UI feedback and recent-template tracking.
The GraphEditor indicator is intentionally lightweight and disappears once the graph becomes a regular saved project.

gemini-code-assist

Code Review

This pull request introduces support for template files with the .mgt extension, allowing users to save, load, and manage templates separately from standard .mg project files. Key changes include a new files.py utility module, updated template discovery in core modules, and UI enhancements such as a 'Recent Templates' menu, a template badge, and improved drag-and-drop handling. The review feedback highlights several high-quality improvement opportunities, including preventing a fall-through bug in file drop handling, specifying UTF-8 encoding when reading files, refactoring path operations to be more Pythonic, optimizing loops that parse file extensions, and adding defensive null checks in QML to avoid potential runtime errors.

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gemini-code-assist · 2026-06-30T14:06:59Z

+        if filesByType["meshroomTemplates"]:
+            if len(filesByType["meshroomTemplates"]) > 1:
+                self.error.emit(
+                    Message(
+                    "Too Many Meshroom Templates",
+                    "A single Meshroom template (.mgt file) can be opened at once."
+                    )
+                )
+            elif filesByType["meshroomScenes"]:
+                self.error.emit(
+                    Message(
+                    "Mixed Meshroom Files",
+                    "Do not mix Meshroom projects and templates."
+                    )
+                )
+            else:
+                return self.loadTemplate(filesByType["meshroomTemplates"][0])


Add return False immediately after emitting errors for too many templates or mixed files. Otherwise, the function will fall through and still attempt to load the scene file if exactly one scene is present in the dropped files, bypassing the error handling.

Suggested change

if filesByType["meshroomTemplates"]:

if len(filesByType["meshroomTemplates"]) > 1:

self.error.emit(

Message(

"Too Many Meshroom Templates",

"A single Meshroom template (.mgt file) can be opened at once."

)

)

elif filesByType["meshroomScenes"]:

self.error.emit(

Message(

"Mixed Meshroom Files",

"Do not mix Meshroom projects and templates."

)

)

else:

return self.loadTemplate(filesByType["meshroomTemplates"][0])

if filesByType["meshroomTemplates"]:

if len(filesByType["meshroomTemplates"]) > 1:

self.error.emit(

Message(

"Too Many Meshroom Templates",

"A single Meshroom template (.mgt file) can be opened at once."

)

)

return False

elif filesByType["meshroomScenes"]:

self.error.emit(

Message(

"Mixed Meshroom Files",

"Do not mix Meshroom projects and templates."

)

)

return False

else:

return self.loadTemplate(filesByType["meshroomTemplates"][0])

gemini-code-assist · 2026-06-30T14:06:59Z

+    if extensionLower(path) != MESHROOM_LEGACY_TEMPLATE_EXTENSION:
+        return False
+    try:
+        with open(path) as file:


Specify encoding="utf-8" when opening the file to prevent potential UnicodeDecodeError on platforms where the default system encoding is not UTF-8 (such as Windows).

Suggested change

with open(path) as file:

with open(path, encoding="utf-8") as file:

codecov · 2026-06-30T14:07:21Z

Codecov Report

❌ Patch coverage is 89.07563% with 13 lines in your changes missing coverage. Please review.
✅ Project coverage is 85.43%. Comparing base (bad1f37) to head (ee14941).
⚠️ Report is 84 commits behind head on develop.
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
meshroom/multiview.py	33.33%	6 Missing ⚠️
meshroom/core/graph.py	75.00%	4 Missing ⚠️
meshroom/core/files.py	88.88%	3 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #3153      +/-   ##
===========================================
+ Coverage    85.39%   85.43%   +0.04%     
===========================================
  Files           73       75       +2     
  Lines        11498    11607     +109     
===========================================
+ Hits          9819     9917      +98     
- Misses        1679     1690      +11

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Copilot

Pull request overview

This PR introduces explicit Meshroom template file handling by adding the .mgt extension, centralizing template detection rules in core, and wiring UI flows to open templates as unsaved graphs while tracking template origin separately for indicators and recent-files.

Changes:

Added meshroom.core.files helpers/constants to detect templates via .mgt extension or legacy .mg header metadata.
Updated UI load/drop flows to route template files through a dedicated “open template” path, track graph.templateFilepath, and maintain a separate recent-templates list.
Added UI affordances (GraphEditor stripes + toolbar badge) to indicate when the active graph originates from a template.

Reviewed changes

Copilot reviewed 16 out of 16 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
tests/test_template_files.py	Adds unit tests for extension/header-based template detection, template init behavior, and template discovery.
meshroom/core/files.py	Introduces centralized template/project extension constants and detection/extension helpers.
meshroom/core/init.py	Updates pipeline template discovery to support `.mgt` and legacy `.mg` templates.
meshroom/core/plugins.py	Updates plugin template discovery to support `.mgt` and legacy `.mg` templates with deterministic ordering.
meshroom/core/graph.py	Adds `templateFilepath` to Graph model and clears it when the graph becomes a regular saved project.
meshroom/multiview.py	Extends dropped-file categorization to include Meshroom templates separately from projects.
meshroom/ui/scene.py	Routes loads to template flow, adds template drop handling, and updates unknown-extension reporting.
meshroom/ui/graph.py	Ensures save-as uses the correct extension for projects vs templates via `withExtension`.
meshroom/ui/app.py	Adds recent-templates persistence and QML-facing properties/slots for template recents.
meshroom/ui/qml/main.qml	Adds template recent-file tracking when opening a file at startup.
meshroom/ui/qml/WorkspaceView.qml	Updates drop-to-open behavior and recent-file updates for projects vs templates.
meshroom/ui/qml/Application.qml	Updates template dialogs/actions/menus and adds a template badge indicator in the UI.
meshroom/ui/qml/GraphEditor/GraphEditor.qml	Adds background stripe indicator for template graphs and recognizes `.mgt` in drag/drop.
meshroom/ui/qml/ImageGallery/ImageListView.qml	Treats templates like projects for drag/drop exclusivity and updates copy text.
meshroom/ui/qml/ImageGallery/ImageGridView.qml	Treats templates like projects for drag/drop exclusivity and updates copy text.
meshroom/ui/qml/ImageGallery/ImageGallery.qml	Updates mixed-file warning text to mention both projects and templates.

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

+            {images, videos, panoramaInfo, meshroomScenes, meshroomTemplates, otherFiles}: Map containing the
+                lists of paths for recognized images, videos, Meshroom scenes, Meshroom templates and other files.
            Node: cameraInit node used to add new images to it
            QPoint: position to locate the node (usually the mouse position)
        """


    def load(self, url):
+        localFile = self._urlToLocalFile(url)
+        if isTemplateFile(localFile):
+            return self.loadTemplate(localFile)
+        return self._loadWithErrorReport(self.loadGraph, localFile)



 import meshroom
 from meshroom.core import pluginManager
+from meshroom.core.files import isTemplateFile


 from meshroom.core import submitters
 from meshroom.core.attribute import Attribute, ListAttribute, GroupAttribute
 from meshroom.core.exception import GraphCompatibilityError, InvalidEdgeError, StopGraphVisit, StopBranchVisit, CyclicDependencyError
+from meshroom.core.files import MESHROOM_PROJECT_EXTENSION, isTemplateFile


servantftransperfect · 2026-07-20T16:41:19Z

Why don't we use the header to check .mgt validity ?

gemini-code-assist Bot reviewed Jun 30, 2026

View reviewed changes

nicolas-lambert-tc force-pushed the feature/explicit-templates-file-management branch 4 times, most recently from e6659e4 to c24ebd3 Compare June 30, 2026 16:33

nicolas-lambert-tc marked this pull request as ready for review July 1, 2026 07:23

Copilot AI review requested due to automatic review settings July 1, 2026 07:23

Copilot started reviewing on behalf of nicolas-lambert-tc July 1, 2026 07:23 View session

nicolas-lambert-tc self-assigned this Jul 1, 2026

nicolas-lambert-tc added the feature new feature (proposed as PR or issue planned by dev) label Jul 1, 2026

nicolas-lambert-tc added this to the Meshroom 2026.1.0 milestone Jul 1, 2026

nicolas-lambert-tc requested review from Alxiice, cbentejac and fabiencastan July 1, 2026 07:25

Copilot AI reviewed Jul 1, 2026

View reviewed changes

nicolas-lambert-tc added 4 commits July 1, 2026 10:20

[core] Add explicit template file handling

5cc6f50

[ui] Add explicit template actions and recents

7bf3157

[tests] Cover explicit template files

efe48f5

[ui] Explicitely indicate opened templates in graph editor

ee14941

nicolas-lambert-tc force-pushed the feature/explicit-templates-file-management branch from c24ebd3 to ee14941 Compare July 1, 2026 08:22

github-code-quality Bot found potential problems Jul 1, 2026

View reviewed changes

cbentejac changed the title ~~Feature/explicit templates file management~~ Explicit templates file management Aug 4, 2026

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Explicit templates file management - #3153

Explicit templates file management#3153
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nicolas-lambert-tc commented Jun 30, 2026 •

edited

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	with open(path, encoding="utf-8") as file:

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