MergeSight Integration

MergeSight for Unity Version Control

MergeSight works with Unity Version Control (UVCS, formerly Plastic SCM) for semantic review and 3-way merge workflows. Teams can inspect workspace changes and concrete changesets as Unity objects and properties, then use Base, Ours, and Theirs context when a scene, prefab, material, or YAML asset needs a merge decision.

7 Wolves July 29, 2026 8 min read Unity Version Control

What MergeSight adds to a UVCS workflow

Unity Version Control already manages repositories, branches, changesets, code reviews, and merges. MergeSight does not replace that system. It adds a Unity-aware review surface for the serialized assets that are difficult to understand in a normal text diff.

With the MergeSight Unity asset review and merge workflow, a team can inspect .unity, .prefab, .asset, and .mat files as GameObjects, components, properties, hierarchy changes, prefab overrides, materials, GUIDs, fileIDs, and references.

Review changed assets in the current UVCS workspace.
Select concrete UVCS changesets as comparison sources.
Search and filter changed assets by path, type, name, and VCS status.
Resolve conflicts through a structured Base / Ours / Theirs model.
Preview, validate, and back up the result before writing it.

Review Unity assets between UVCS changesets

The UVCS command line can list changes between changesets. MergeSight uses the installed cm client to surface workspace, branch, and changeset sources inside Review Mode. For reliable content loading, choose concrete changesets when a branch source is ambiguous across cm versions.

Open Tools/MergeSight/New Window in the Unity project.
Select Unity Version Control as the review provider.
Choose the source and destination changesets.
Filter the changed list to scenes, prefabs, materials, or generic YAML assets.
Open an asset and review object-level and property-level changes.

This is useful before a merge or code review because it answers what changed in Unity terms, not only which YAML lines changed.

Resolve UVCS scene and prefab conflicts

UVCS uses a 3-way merge model: the base is the common ancestor, the destination is the current side, and the source is the incoming side. MergeSight maps those inputs into Base, Ours, and Theirs and keeps unresolved decisions visible.

There are two integration paths:

Direct Editor loading. When cm status exposes complete contributor metadata, MergeSight can load the three sides from the active workspace.
External merge wrapper. Configure the supplied UVCS/Plastic wrapper so the client passes ancestor, destination, source, output, and item path into MergeSight. This is the reliable fallback when direct metadata is incomplete.

Set up the integration

Set Unity Asset Serialization to Force Text.
Install the UVCS desktop/CLI client and confirm that cm status works inside the workspace.
Open Tools/MergeSight/VCS Integration Setup.
Enable UVCS startup conflict detection if the team wants automatic prompts.
Copy the interactive wrapper command into the UVCS external merge-tool configuration when direct loading is not enough.
Test the setup on a temporary branch and a non-critical text-serialized asset.

Requirements and limits

Area	Supported workflow	Limit
Review	Workspace changes and concrete changesets	Branch content loading can vary by `cm` version; select a changeset when needed.
Conflict loading	Direct metadata or external wrapper	Complete Base / Ours / Theirs content is required.
Assets	`.unity`, `.prefab`, `.asset`, `.mat`	Assets must be text-serialized.
Automation	Auto-safe CLI merge tool and interactive Unity UI	The CLI does not guess unsafe design decisions.

FAQ

Does MergeSight support Unity Version Control?

Yes. MergeSight supports Unity Version Control / Plastic SCM review and merge workflows through the installed cm client, provider detection, changeset comparison, direct conflict-side loading when metadata is complete, and external merge wrappers.

Can MergeSight compare two UVCS changesets?

Yes. Review Mode can use concrete UVCS changesets as comparison sources and show changed Unity assets as semantic object, component, property, hierarchy, and reference changes.

Does MergeSight replace the UVCS desktop client?

No. UVCS remains the source of truth for repositories, branches, changesets, locks, and merge operations. MergeSight adds Unity-aware review and conflict resolution for text-serialized assets.

Can MergeSight open every UVCS conflict directly?

Direct loading depends on contributor metadata exposed by the installed cm client and active workspace. When complete metadata is unavailable, use the supplied interactive UVCS merge wrapper.

Does the UVCS integration require a web service?

No. Core review and merge processing runs locally. The relevant UVCS command-line client and workspace access are still required.

Summary

UVCS owns history

Branches, changesets, locks, code reviews, and merge operations stay in Unity Version Control.

MergeSight adds context

Unity YAML becomes objects, components, hierarchy, references, overrides, and properties.

Unsafe cases stay explicit

Complete 3-way inputs, preview, validation, and fail-closed behavior protect the write step.

Use UVCS for version-control operations and MergeSight when Unity asset meaning must be reviewed before a changeset or merge is accepted.

Next step

Open Tools/MergeSight/VCS Integration Setup, verify the cm client, and test a changeset comparison before configuring the external merge wrapper.