Level Proto 2D Metroidvania

Overview

Level Proto replaces the usual "resize a bunch of white cubes" blockout workflow with a single component, ProtoShape2D, that you draw and edit directly in the Scene View — arbitrary polygons, not just boxes — plus a runtime grid material so flat areas still give you a sense of scale and movement while playtesting.

Installation

This asset is distributed as a plain Assets-folder package, following the Unity Asset Store's required layout — everything lives under a single folder named after the asset, not under Packages/.

1. Import the .unitypackage (or copy this folder) into your project — it installs under Assets/CloudedStudio/LevelProto2dMetroidvania.
2. Confirm your project uses Universal Render Pipeline (both the standard Universal Renderer and the 2D Renderer are supported by the runtime grid shader).
3. Confirm the Input System package is installed (required by Proto Player's PlayerInput component).

Demo Scene

Open Demo/Level Proto 2D - Material Showcase.unity for a self-contained, playable tour of the asset. It compares Proto Grid, Cavern Stone, and Mossy Ruins side by side using real Proto Shapes rather than screenshots.

Quick Start

1. Create a shape Use GameObject > 2D Object > Proto Shape for a default quad, or select the Draw Proto Shape tool in the Scene View toolbar and click out a custom outline (click the first point again, or press Enter, to close it).
2. Shape it With the shape selected, drag any vertex or edge directly in the Scene View. Click an edge (without dragging) to insert a new point there; hover a vertex and press Delete to remove it.
3. Grow it Switch the Inspector's Scene View Edit Mode to Extrude Edge, then drag an edge outward to push out a new section. Hold Shift to drag freely instead of snapping to the edge normal.
4. Mark areas Add GameObject > 2D Object > Proto Label for callouts like "Boss Arena" — it's a normal Transform, so the built-in Move tool repositions it.
5. Export Use Tools > Level Proto > Export PNG or Export JSON to hand the whole prototype off — to an artist, a design doc, or another tool.

Proto Shape 2D

ProtoShape2D is a local-space polygon: a list of Vector2 vertices that drives a generated Mesh (filled with Fill Color) and, optionally, a matching PolygonCollider2D. It auto-adds MeshFilter/MeshRenderer and manages its own mesh lifecycle — you never need to touch those directly.

Scene View Editing

Selecting a ProtoShape2D turns on interactive editing directly in the Scene View — the same interaction model Unity's own PolygonCollider2D and SpriteShapeController editors use.

Curves are tessellated into the same evaluated outline used by the generated mesh, collider, procedural material boundary, and PNG export. JSON format version 4 preserves the original control points, tangent modes, tangent offsets, outline settings, and inner-shadow settings.

Every operation is a full Undo step. Interactive Scene View dragging works on a single selected shape at a time — with multiple shapes selected, shared fields (color, collider toggle, etc.) still multi-edit normally in the Inspector, just not vertex dragging.

Extrude Edge Mode

Toggle Extrude Edge in the Inspector's Scene View Edit Mode selector to grow a shape from one of its edges — useful for pushing out a corridor or ledge without redrawing the whole outline.

• Click-drag an edge outward; two new vertices are inserted and dragged along the edge's outward normal.
• Hold Shift to drag freely instead of snapping to the normal direction.
• Releasing without crossing the drag threshold cancels cleanly — no zero-area sliver gets left behind.
• Hold Alt while clicking a vertex to edit it instead, without leaving Extrude Edge mode — see Scene View Editing.

Snapping

Two independent snapping systems, both on by default and toggleable from the Inspector while a shape is selected:

• Grid Snap — snaps dragged vertices and edges to the current Grid Size in Unity's Scene View Grid and Snap overlay.
• Angle Snap — if an edge to a neighboring vertex is within a few degrees of horizontal/vertical, it's forced perfectly level, so you don't get accidental micro-slopes.

The two combine as: angle-snap first (straight edges win), then grid-snap the result. Hold Ctrl while dragging to temporarily disable both.

Grid Ruler (Edit-Time)

While editing, a numbered grid overlay is drawn on Unity's current Scene View grid, using the same size, origin, and rotation as snapping. When zoomed out, it skips cells by whole-number multiples so it stays readable without ever drifting off-grid. This is purely an editing aid; it doesn't render at runtime. Toggle it from the same Inspector panel as the snapping options.

Runtime Visual Materials

Flat, uniformly colored platforms make it hard to feel the camera or character moving. ProtoGridUnlit.shader solves that with a two-tier grid and ruler-style tick marks, rendered in Play Mode and in builds — not just in the Editor.

Works with both the standard Universal Renderer and URP's 2D Renderer — the shader ships two passes (UniversalForward and Universal2D) so it renders correctly either way. Per-shape fill color and the shape's own edge list (used for tick placement) are pushed per-instance via MaterialPropertyBlock; every shape otherwise shares one material instance.

Use Visual Style in the ProtoShape2D Inspector to switch among Proto Grid, Solid, Cavern Stone, and Mossy Ruins. Every bundled style supports the Universal2D and UniversalForward passes, uses each shape's Fill Color, and exposes shared Outline and Inner Shadow groups. Outline has an explicit checkbox, solid-black default color, and Thickness. Inner Shadow has Color, Blend Mode (Multiply by default), Choke, and Size. Both follow the real polygon boundary and are stored per shape. A Custom material manages its own effects and does not receive these bundled controls.

Proto Label 2D

ProtoLabel2D is a lightweight text marker for naming areas ("Water Temple Entrance", "Boss Arena"). It has no runtime visual — it's an authoring/export-only concern, visible as Scene View text (whether or not its GameObject is selected) and included in PNG/JSON exports.

Position is just the GameObject's transform, so the standard Move tool (and its built-in Undo) repositions it — no custom Scene View dragging needed. Drawing uses Unity's [DrawGizmo] attribute rather than a custom Editor's OnSceneGUI, specifically so labels stay visible whether or not their GameObject is selected.

Proto Player

A minimal, movement-only 2D character so you can actually walk your blockout and feel whether traversal works, not just look at it. GameObject > 2D Object > Proto Player creates one fully-configured GameObject — no prefab asset, no setup. It's a simplified port of a fuller character controller (combat, combos, health, dash, animation state machines) with everything except walking and jumping stripped out.

No animation, no combat, no health — the sprite renderer just shows a fixed placeholder sprite, flipped to face left/right as you move. Ground detection defaults to the Default physics layer, matching where ProtoShape2D objects already live, so it works immediately against your blockout with no Layer/Tag setup.

Proto Shape Group

ProtoShapeGroup is a purely organizational marker component (GameObject > 2D Object > Proto Shape Group) — parent a set of ProtoShape2D/ProtoLabel2D objects under it in the Hierarchy, and its Inspector (styled to match ProtoShape2D's, with the same banner header and collapsible sections) shows a Group Contents section reporting how many it found, plus an Export This Group section with its own Export PNG... / Export JSON... buttons.

These open the exact same export windows as Tools > Level Proto > Export PNG/JSON — same options, same code — just pre-scoped to that group's own hierarchy instead of the whole active scene. Useful for exporting one room/section of a larger level on its own, without touching everything else in the scene.

PNG Export

Tools > Level Proto > Export PNG rasterizes every ProtoShape2D/ProtoLabel2D in the active scene straight from their data — vertex lists and text, not a camera screenshot — sized by a configurable Pixels Per Unit.

The output size is estimated live before you export, and very large images (beyond 8192px on an axis) prompt for confirmation before allocating memory.

JSON Export

Tools > Level Proto > Export JSON dumps the prototype's raw data — local-space vertices plus each shape's full transform, so a consumer can reconstruct exact world-space geometry rather than working from a flattened approximation.

Schema

Copy{
  "formatVersion": 4,
  "sceneName": "SampleScene",
  "exportedAtUtc": "2026-08-02T14:03:11.0000000Z",
  "shapes": [
    {
      "name": "Proto Shape",
      "position": { "x": 0, "y": 0, "z": 0 },
      "rotation": { "x": 0, "y": 0, "z": 0, "w": 1 },
      "scale":    { "x": 1, "y": 1, "z": 1 },
      "localVertices": [
        { "x": -1, "y": -1 },
        { "x":  1, "y": -1 },
        { "x":  1, "y":  1 },
        { "x": -1, "y":  1 }
      ],
      "fillColor": { "r": 1, "g": 1, "b": 1, "a": 1 },
      "outlineEnabled": false,
      "outlineColor": { "r": 0, "g": 0, "b": 0, "a": 1 },
      "outlineWidth": 0.06,
      "innerShadowEnabled": false,
      "innerShadowColor": { "r": 0, "g": 0, "b": 0, "a": 0.5 },
      "innerShadowBlendMode": "Multiply",
      "innerShadowChoke": 0.15,
      "innerShadowSize": 0.2,
      "generateCollider": true,
      "sortingOrder": 0,
      "tags": "ground,walkable"
    }
  ],
  "labels": [
    {
      "name": "Proto Label",
      "position": { "x": 4, "y": 1.5, "z": 0 },
      "text": "Boss Arena",
      "color": { "r": 1, "g": 1, "b": 1, "a": 1 },
      "worldFontSize": 1.0,
      "alignment": "MiddleCenter"
    }
  ]
}

Colors are linear 0–1 float components (not 0–255). alignment is the TextAnchor enum name as a string. tags is whatever free text you typed into the shape's Tags field - the package doesn't parse or use it, it's purely a hook for your own JSON-consuming tooling (e.g. a comma-separated list, a category name, a pipe-delimited key set - your call). The window shows a live count of shapes/labels found before you export, plus a Pretty Print toggle for human-readable vs. compact output.

Project Settings

Shared defaults live in a ProtoShapeSettings asset, lazily created the first time it's needed at Assets/Settings/ProtoLevelSettings.asset.

Material Properties — Proto Grid Unlit

All exposed on the material Inspector for Level Proto/Proto Grid Unlit. Sizes/lengths are in world units.

Per-shape, non-Inspector properties set automatically via MaterialPropertyBlock: _EdgeA / _EdgeB (the shape's local-space edge list, capped at 64 edges) and _EdgeCount — these drive ruler-tick placement and aren't meant to be hand-edited.

Bundled visual styles

Level Proto/Proto Solid uses only _BaseColor. Level Proto/Proto Cavern Stone exposes stone palette, texture/strata scale, crack scale/width, and surface-detail controls. Level Proto/Proto Mossy Ruins exposes block and mortar sizes, stone/moss palettes, surface scale, moss scale, and moss coverage. Along with Proto Grid, all four receive per-shape Fill Color, Outline, Inner Shadow, and evaluated boundary data through a MaterialPropertyBlock.

Menu Reference

Package Architecture

Namespace cloudedstudio.LevelProto2dMetroidvania (Runtime), with editor-only types nested under cloudedstudio.LevelProto2dMetroidvania.Editor. Split into two assemblies so nothing editor-only leaks into player builds.

Assets/CloudedStudio/LevelProto2dMetroidvania/
├── Runtime/            ProtoShape2D, ProtoLabel2D, geometry (triangulator,
│                        polygon utilities), the grid shader
│   └── Player/          Proto Player's components, bundled sprite and
│                        Input Actions asset
├── Editor/              Scene View editors/tools, snapping, grid ruler,
│                        PNG/JSON exporters, project settings
└── Tests/Editor/        EditMode unit tests (triangulator, rasterizer,
                          polygon utilities)

Known Limitations

• Interactive Scene View vertex/edge dragging works on one selected shape at a time; multi-selection still supports shared-field edits (color, collider toggle, etc.).
• The grid shader's edge list (used for ruler ticks) is capped at 64 edges per shape — beyond that, extra edges simply don't get tick marks; the grid pattern itself is unaffected.
• Ruler ticks only appear on edges within roughly 2° of horizontal or vertical, by design — diagonal edges show the grid pattern but no ticks, to avoid visual clutter where vertical and horizontal ticks would otherwise overlap.
• Text rendering (Scene View labels and PNG export) uses Unity's legacy Font glyph API, whose built-in resource name has changed across Unity versions. The package falls back automatically (LegacyRuntime.ttf → Arial.ttf → an OS font by name) — worth a quick visual check after exporting with labels on a new Unity version.
• Self-intersecting polygons are detected and flagged, not auto-corrected; fix the outline to resume normal mesh/collider updates.
• Proto Player has no animation - it's deliberately just a movement/jump rig for playtesting traversal, not a character template. It does flip to face its movement direction (CharacterSpriteFlipper); untick "Default Faces Right" on that component if your sprite's source artwork faces left instead. Ground detection defaults to the Default physics layer; if your blockout uses other layers for ground, update CharacterGroundChecker's Ground Layer field.