The manual

1. Import the package from the Asset Store (Window›Package Manager›My Assets), or a .unitypackage through Assets›Import Package›Custom Package…
2. Everything lands in Assets/Kelpo/3DMultitool/. No other packages, no project settings to change. You can move the Kelpo folder anywhere under Assets.
3. Open the tool: Tools›Kelpo›3D Multitool›Open 3D Multitool, or Ctrl+Shift+K (Cmd+Shift+K on a Mac).

The short version of the whole trip. The Getting started tutorial shows the same thing in detail, with clips.

1. Model. Press Cube. You're in Face mode: click a face, press W and Shift+drag the gizmo to extrude. 1 2 3 switch Vertex, Edge and Face mode. Block out a crate, a pillar, anything.
2. Sculpt (optional). Subdivide once or twice, then Draw, Inflate or Flatten for organic detail. Hold Shift to smooth, Ctrl to carve.
3. Retopo (optional, after heavy sculpting). Brush green over what matters, set Keep % to about 25, Preview reduction, then Apply.
4. UVs. Unique unwrap.
5. Paint. Resolution 1024, Start painting. In Material mode one stroke lays down color, metallic and smoothness. Try the Image tip for dirt, and bake ambient occlusion under Maps & bakes.
6. Colliders. Generate collider, or draw one.
7. Export. Name it, Export as prefab…, pick a folder inside Assets. You get the mesh, PNG maps, material, collider and a prefab.

The tabs run top to bottom in the order you'll usually use them, and each one feeds the next. You can jump around.

Two ways to texture

1 2 3 4 5 6 7

Drag a slider's label to scrub its value, or type into the field next to it. A row of choices that doesn't fit a narrow window turns into a dropdown. Very wide windows keep the controls in a centered column.

Polygon modeling on a Kelpo Object: a component that holds the editable mesh and keeps the MeshFilter in sync.

Create

• Cube, Plane, Sphere (an icosphere) and Cylinder use standard sizes: cube 1 segment per axis, plane 4×4, sphere 2 subdivisions, cylinder 16 sides and 1 height segment.
• Custom sets size and segments first. Cylinders take sides and height segments, spheres take subdivision levels. The settings stay for the window session, and Reset restores the defaults.
• Placement: Scene View Focus (where you're looking) or World Origin (exactly 0, 0, 0).
• Convert selection makes any imported MeshFilter editable. Material slots carry over. Keep Preserve existing UV mapping and textures on if its current textures must keep working.

Add parts to the same object

With an object selected, press + New and tick Add to … as a part. The new shape goes into the same object as a loose part, on a material slot you choose, and it comes in selected. Build every part before unwrapping: adding parts is switched off once the object has UVs, to protect the textures.

Select

Move, extrude, inset

• W E R: Unity's own move, rotate and scale work on your selection. Unity's object gizmo steps aside while elements are selected. Gizmo hides Kelpo's.
• Shift+drag the gizmo extrudes. Faces grow walls first, open border edges grow new faces, and the fresh part then follows the move, rotate or scale.
• Extrude works on a whole region: only its outer border grows walls. A negative distance makes a recess.
• Inset shrinks faces inward and adds a border. Each face on its own insets every face separately.

Edge and vertex tools

With nothing selected, Delete and Backspace go to Unity as usual. All Model keys can be changed under Shortcuts → Customize keys.

Face tools

Mirror

Pick X, Y or Z and model one half. The other half follows live, welded at the seam. The sliders button next to it opens the settings:

Whole mesh

Simplify selection

Thin out part of a mesh, for example after Refine or heavy sculpting. Select the faces in Face mode, open Simplify selection, set Keep triangles and Feature angle, then Preview simplification and Apply or Cancel. The border of the selection stays put. Lower feature angles protect more creases. Do it before unwrapping.

Light, organic sculpting tuned for game props: rocks, roots, bark, dents.

Hold Shift at the start of a stroke to smooth with any brush. Hold Ctrl to invert the brushes that have a direction. [ ] or Shift+scroll change the size, Ctrl+scroll the strength.

Settings worth knowing

The smart optimize step: bring the triangle count down while protecting what defines the shape.

1. Protect. Brush green dots over silhouettes and features that matter. Shift+drag erases, Clear mask starts over. Protect sharp edges (on by default) locks outlines and edges at or above Edge angle.
2. Reduce. Method Reduce keeps the surface and removes triangles. Keep % is the budget, Mask strength how hard the green areas resist. The result row shows the expected count.
3. Preview. Preview reduction shows a proposal. Flip between Original and Result, read the real counts, then Apply or Cancel. Revert undoes the last Apply.
4. Or remesh. Method Remesh rebuilds all topology to Detail size, then gives triangles back on flat areas (Adaptivity). Same Preview, Apply and Revert.
5. Keep a copy. Save mesh as asset….

The mask survives each reduction, so you can apply several times. If sharp-edge protection stops above your target count, Kelpo says so: raise the angle, turn it off, or paint a narrower mask.

Painting needs every face to have its own patch of texture. Tiling materials need UVs that repeat.

The Layout card at the top previews the islands (overlaps in red) and shows island count, coverage and texel density. It warns about overlapping UVs, where paint would land on several surfaces, and vertices outside 0–1, fine for tiling but not for painting. Checker puts a test pattern on the mesh for a moment, Seams draws the cuts in the Scene view.

Both work on several selected objects at once, imported and skinned meshes included. Each object gets its own layout; they aren't packed into one atlas. For shared texture space, build the pieces as parts of one Kelpo object, unwrap together, then Detach.

Paint color, metal, shine and height straight onto the mesh in the Scene view, in layers. Standard metallic workflow.

Start a session

• Pick a Resolution. 2048 is the maximum, 1024 uses far less memory. On objects with several materials, choose the Paint slot.
• Start from the existing material and maps brings the current look in as the Base layer. Turn it off for a blank Kelpo material.
• Continue offers earlier work first: a session file, a recovery checkpoint, or the maps on the material.
• Closing the window doesn't end the session. Reopen it, select the object and keep going.

Channels and the brush

Image stamps

Tip → Image and assign any Texture2D. Color: Multiply with image or Brush color only. Shape from: Alpha for transparent PNGs, Brightness or Darkness for plain light or dark images. Rotation and Random rotation per dab turn the stamp. On the Height channel, the image's brightness becomes the relief.

Brush presets

Click + next to My brushes, name it, Save. Pick it from the dropdown later. Update overwrites it, Load brings it back after experimenting, Delete and Clear all remove presets. A preset stores the channel and material values, tip, hardness, flow, spacing, stamp and the Height limit. It doesn't store layers, textures or the face limit. Presets live in your editor settings, outside Assets, so test presets never end up in a package.

Layers

• Up to 8 layers. + adds an Empty layer or a Carved material preset.
• The circle picks the layer you paint on. Click a name to rename it, the eye to hide it, and drag the slider for opacity.
• Shift+drag erases on an upper layer to show the ones below. Base can't be erased.
• Fill layer fills the whole layer with the current values. Good for base coats.
• Every layer change is undoable, a deleted layer included.

Height masks on layers

A layer can show only where the painted Height says so. Click its Height mask button and choose Carved (below neutral), Raised (above), Edges (convex rims) or Cavities (folds). Tune Depth or Curvature and Softness. Preview shows the allowed area in orange. Everywhere removes the condition. The layer keeps following later Height painting and undo.

Paint only on

Both limits work together: a dab has to pass both. Fill layer is off while a face limit is on. The face limit is for this session only. To reuse an area, capture it and choose Faces → Save current / manage areas…. Saved areas are stored with the object, so save the scene.

Normal map and ambient occlusion

• Normal map. Built from Height as you paint. Its strength sits under Maps & bakes → Normal map. Generate rebuilds it, Clear removes it. Erasing Height erases the relief too.
• Ambient occlusion. Maps & bakes → resolution, samples, Reach and strength, then Bake. Bake at 256 while trying things and 512 for the final. It's the biggest single “looks finished” button for rocks and props, and it exports with the prefab.

Saving your paint

Until you save, the working maps live inside the scene: about 43 MB of raw data at 2048, and roughly twice that in a text scene file. Save material + textures (or Export) swaps that for compact project assets. Without a session file, Continue painting resumes from the material's maps with the layers flattened.

Physics rarely needs every triangle. Generate a simplified collider, or draw one around exactly what matters.

Generate

Simplify the mesh → set Keep % → Generate collider. Works on any selected mesh, imported ones included, and respects the Retopo protect mask. Tick Convex if the object has a moving Rigidbody: Unity needs convex colliders on those.

Draw

Points land on the selected mesh only, so a miss can't jump to the scenery behind it. Tick Allow points off the surface for a flat construction plane. Crossing edges, doubled points and zero-area spikes turn red and Build waits until they're fixed. The last good collider stays in the meantime.

While the tab is open, the collider shows as a green wireframe. The On this object card shows its triangle count and a Remove button.

One click turns the working object into plain Unity assets that don't need Kelpo.

1. Select the finished object and give it a Name. It follows the selection until you type your own.
2. Pick the options below, then Export as prefab… and a folder inside Assets.
3. Kelpo checks the saved prefab, then asks whether to keep the editable scene object or delete it (undoable).

With the default Write material and texture copies you get:

Nothing half-done: files are backed up before anything is written. If a write, an import or the final check fails, the folder goes back to how it was. Existing files are only overwritten after you confirm. Save material + textures… has the same protection.

For a skinned mesh, Export only saves and rebinds the materials and maps. The rig, mesh and animations stay untouched.

Where it says Ctrl/Cmd, use Cmd on a Mac.

L, Shift+L, C, Ctrl+R, Delete and Backspace are defaults. Change them under Shortcuts → Customize keys in the Model tab.

Kelpo picks the right lit shader for the active pipeline on its own. To switch the bundled demo and sample materials, run Tools›Kelpo›3D Multitool›Adapt Demo Materials to Active Pipeline. It only touches the demo materials, and it's safe to run again after switching pipelines.

• Demo/Kelpo3DMultitoolDemo.unity: sample props and an instruction panel, made for URP.
• Samples/: props made with the tool. Each folder holds the prefab and what Export wrote for it (mesh, material, maps, collider where used), so they double as examples of export output.

• No bevel or edge slide yet. Loop cuts land at edge midpoints, then slide them with W.
• The simplifier is a weighted edge collapse, not full QEM. Very low percentages (under 5%) can get lumpy, and UVs don't survive reduction.
• Topology changes can clear UVs even when the vertex count stays the same. Finish the shape before the final unwrap.
• Paint undo keeps the last 10 texture-changing steps. A Fill at 2048 records the whole channel, so it's much heavier than a stroke.
• A paint session edits one material slot at a time.
• Session files belong to one object. They don't carry over to a mesh with a different unwrap (Kelpo warns you).
• Paint sessions don't persist inside Prefab Mode. Save material + textures before closing the stage, or paint on a scene instance.
• Ambient occlusion is baked on the CPU, so 1024 and up takes a while (you can cancel). It's self-occlusion only.
• Drawn collider outlines must be simple shapes. Crossing or duplicate points are refused, not guessed.
• Separately exported parts get their own material copies unless you choose Reuse assigned material assets (see the chest recipe under Export).
• Graphics backends without region texture copies use slower full uploads while painting.

The code ships readable and un-obfuscated. It's meant to be read and extended.

Adding a tab: make a class with OnGUI() (and optionally OnSceneGUI(SceneView)), add it to KelpoWindow.Tab, both switch statements and the title, subtitle and icon arrays. Build the layout from KelpoUI cards so spacing and both editor themes stay consistent.