SAM'S FORGE

SUBSTRATA-READY WORLD AUTHORING

BUILD THE WORLD.

A fast browser-based toolkit for creators who want editable structures, procedural materials, sculpted terrain, clean GLB output, float32 EXR heightfields, and RGB material masks. Built for creating worlds in Substrata.

SUBSTRATA WEBSITE
01 · ARCHITECTURE

Structure Builder

Draw architectural forms directly and export editable, game-ready structures without entering a full modeling application.

  • Walls, arcs, vaults, domes, floors, ceilings, and roofs
  • Door and window openings
  • Whole-object and individual-surface material assignment
  • AI-readable project JSON and GLB export
02 · SURFACES

Material Lab

Create procedural PBR materials independently. New and updated slots refresh when you open Structure Builder.

  • Concrete, wood, clay, metal, stone, and plaster presets
  • Base color, normal, ORM, and height maps
  • Live 3D preview and editable material recipes
  • Texture-map ZIP export
03 · OBJECTS

Prop Generator

Create dimensionally editable furniture, doors, and windows from practical presets, then export named GLB parts.

  • Couches, chairs, tables, desks, and beds
  • Doors with frames, panels, glass inserts, and handles
  • Windows with frames, mullions, glass, and sills
  • Shared project material import and editable JSON
04 · LANDSCAPE

Terrain Sculpt + Mask Painter

Start with an island, archipelago, square, or empty ocean and draw the actual elevation field.

  • Connected mountain-range strokes
  • Lowlands, beaches, rivers, valleys, smoothing, and sea carving
  • Automatic RGB mask generation with manual paint overrides
  • Substrata-ready float32 EXR export

SHARED WORKFLOW

01 · CREATEDraw structures or sculpt the terrain directly.
02 · REFINEAdjust materials, surfaces, elevation, and masks.
03 · PREVIEWInspect the result before export.
04 · EXPORTSend GLB, EXR, PNG, or project JSON into your world pipeline.
SEARCHABLE GUIDE

HOW TO USE SAM'S FORGE

Search by task, feature, file type, or tool. The guide is organized by Structure, Materials, Props, Terrain, projects, and Substrata export.

GETTING STARTED

Forge Workflow

  1. Open a tool from the top navigation or Overview page.
  2. Create or edit your asset.
  3. Preview the result inside the tool.
  4. Save the editable project file before exporting final assets.

Project files vs exports

Project files preserve editable settings. GLB, EXR, PNG, and ZIP exports are the files used outside Forge.

Save the project file as well as the export. The project file is what lets you return and keep editing later.
GETTING STARTED

Reading the Interface

The top toolbar contains frequent commands such as mode, view, undo, redo, save, load, and export. The left panel changes according to the active tool. The center area is the main editor or preview.

Hidden and disabled controls

Settings that do not apply to the current tool are hidden. A disabled command is relevant but needs a prerequisite, such as selecting an object first.

STRUCTURE

Build Walls and Rooms

Room

  1. Choose ROOM.
  2. Click one corner.
  3. Click the opposite corner.
  4. Enable floor or ceiling creation in Tool Parameters when needed.

Wall

  1. Choose WALL.
  2. Click the start and end points.
  3. Keep Continue Wall Chain enabled to draw connected walls.

Grid snap controls placement increments. Connected plain walls use smoothed mitered joints.

STRUCTURE

Add Doors and Windows

  1. Choose OPENING.
  2. Select Door or Window.
  3. Set width, height, sill, and arched top.
  4. Click the straight wall where the opening should appear.

The sill is normally zero for a door and raised for a window. Openings currently apply to compatible straight walls.

STRUCTURE

Use More Shapes

  • Arc: click center, radius/start, then sweep end.
  • Column: set radius and height, then click to place.
  • Vault: click its two axis endpoints. Rotate after placement for sideways forms.
  • Dome: click center and radius. Select it to edit the igloo-style entry.
  • Plane / Slab: click perimeter points and press Enter to close.

Dome panels, raised ribs, and the entry tunnel can receive separate materials.

STRUCTURE

Select and Transform

  • Click an object in Select mode.
  • Shift-click to add or remove objects from a multi-selection.
  • Use Move, Rotate, or Scale in the toolbar.
  • Use the Selection panel for exact numeric values.
  • Use the Scene outliner to select hidden or difficult objects.

Duplicate, Group, Delete, Focus, and Move to Level are available when an object is selected.

STRUCTURE + MATERIALS

Assign Separate Surface Materials

  1. Create or load material slots.
  2. Choose PAINT SURFACE.
  3. Click a face or surface group.
  4. Choose the material slot to apply.

Supported surface groups vary by object. Examples include wall faces, tops, edges, roof planes, dome panels, dome ribs, and entry tunnels.

Use Clear Surface Override in the Selection panel to return that surface to the object's default material.
STRUCTURE

Use a Reference Underlay

  1. Open the Scene panel.
  2. Under Reference Underlay, load an image.
  3. Adjust width, depth, offset, rotation, and opacity.
  4. Build over the image while the grid remains visible.

The underlay is a view-only guide and is not included in GLB exports.

STRUCTURE

Change the Viewer Background

Use the Light BG / Dark BG command in the Structure toolbar. This changes only the 3D viewport background and fog. It does not change the interface or exported model.

Use the muted light background when dark materials are difficult to see.
MATERIALS

Create a Material

  1. Select a preset: Concrete, Wood, Clay, Metal, Stone, or Plaster.
  2. Set the material name and two colors.
  3. Adjust scale, detail, roughness, metalness, normal strength, and seed.
  4. Choose Generate to rebuild the maps.

Randomize changes the procedural seed and related variation while preserving the general material type.

MATERIALS

Preview and Export Texture Maps

Switch between 3D Preview and Texture Maps in the toolbar. The generated set contains Base Color, Normal, ORM, and Height maps.

  • Resolution: output pixel dimensions.
  • Tile size: real-world width of one texture repeat in meters.
  • Maps ZIP: downloads the complete generated texture set and recipe.
MATERIALS

Use Project Material Slots

  • Load Slot: copy an existing project material into the editor.
  • Update Slot: replace the selected slot with the current recipe.
  • Add as Custom Material: create a new project slot.

Structure refreshes the shared material library when the tool is opened.

PROPS

Create Furniture

  1. Select Furniture in the toolbar.
  2. Choose a preset such as couch, chair, table, desk, or bed.
  3. Adjust Dimensions and Construction settings.
  4. Assign the visible material roles.
  5. Fit the preview and export GLB.

Only settings applicable to the selected furniture type are displayed.

PROPS

Create Doors and Windows

Choose Door or Window from the prop type control. Door settings include frame, panels, glass inserts, and handles. Window settings include frame, mullions, glass, and sill.

Material roles update for the active prop, so irrelevant blanket, pillow, glass, or accent fields remain hidden.

PROPS

Assign Prop Materials

Material roles represent named parts rather than individual triangles. Common roles include Primary, Secondary, Accent, Frame, Glass, Blanket, and Pillows.

The displayed roles depend on the selected prop. Shared Structure and Material Lab slots can be imported where available.

TERRAIN

Sculpt Terrain Heights

  1. Choose Height mode.
  2. Select Mountain, Raise, Lower, Lowland, Coast, River, Smooth, or Sea.
  3. Adjust the contextual brush controls.
  4. Drag on the terrain canvas.

Mountain exposes Ridge Sharpness. Lowland exposes Lowland Target. Smooth hides strength because it blends nearby heights.

TERRAIN

Choose a Base Terrain

Open Base Terrain and select Island, Archipelago, Square, or Empty Ocean. Set sea, land, and peak ranges before generating.

Regenerating the base terrain replaces the current heightfield. Save the project first when you may need the existing version.
TERRAIN

Paint the Material Mask

  1. Choose Mask mode.
  2. Select the desired material channel.
  3. Adjust brush radius and opacity.
  4. Paint overrides on the terrain.

The automatic RGB mask is generated from elevation and terrain rules. Manual painting overrides selected areas. Use the mask preview and opacity controls to inspect alignment.

TERRAIN

Paint a Tree Exclusion Mask

Use the tree-mask painting mode to mark regions where trees should not appear. The exported mask is a separate black-and-white PNG intended to remain aligned with the heightfield and material mask.

Paint roads, beaches, structures, clearings, and other no-tree areas before export.

TERRAIN

Inspect the 3D Preview

Choose 3D Preview to inspect the current heightfield. Adjust the vertical preview scale when relief looks too flat or exaggerated. Reset View restores the preview camera without changing terrain data.

The preview scale is visual and does not replace the exported height range settings.

EXPORT

Export Structures

  • Save: editable Structure project JSON.
  • GLB: model geometry and material assignments.
  • ZIP: textured package when generated material maps are included.

Use World origin to preserve scene coordinates or Center on Floor to produce a centered export.

EXPORT

Export Terrain for Substrata

  • EXR: float32 heightfield.
  • Material Mask: RGB PNG.
  • Tree Mask: black-and-white PNG.

Keep Substrata vertical orientation enabled for Substrata imports. The same orientation is applied to the heightfield, material mask, tree mask, and related previews so they remain aligned.

PROJECTS

Save, Load, and Back Up

Forge may preserve recent state in browser storage, but downloaded project files are the dependable backup. Use Save before major changes, browser resets, or switching computers.

Load restores the tool-specific editable project format. A final GLB, EXR, or PNG normally cannot restore all editor settings.

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