The Canvas Bench

Canvas paints in six PBR channels at once, with a layer stack per channel, non-destructive masks, and curvature-driven wear that reads your mesh's own geometry. That combination is what separates it from "a paint program that draws on a model" — and it's the part most people never switch on, because nothing on screen tells you it's there.

This page is the missing instruction. Every control named here exists in the shipping build; every number is one you can type in. Where a technique comes from wider practice rather than from Canvas, it's marked as such and sourced at the bottom.

Step 01Get a mesh that can hold paint

Painting is UV-bound. Canvas picks the triangle under your cursor, converts the hit to a UV coordinate, and stamps into the texture there. No UVs, no paint — so the first thing to settle is whether your model has a usable layout.

Open one with Open Model…. If it arrives without UVs, Canvas says so in the status line. Fix it from the Auto-UV menu, which offers five routes:

Auto-UV changes nothing you can see — it rewrites coordinates, not pixels. So Canvas flips on the UV Checker automatically when it finishes. Read the checker before you paint a single stroke: squares should be square and roughly the same size everywhere. Stretched squares mean stretched texture. Squares that shrink on one part mean that part gets less resolution than its neighbours.

That second reading is texel density — pixels per unit of world space — and keeping it uniform across an asset is what makes a set of props look like they come from one world rather than a bring-and-buy sale. Ascent of Ashes is played at a fixed isometric distance, which is a gift: you can pick one density and hold it everywhere, because nothing is ever inspected from 20cm away. Set it by what the camera actually resolves, not by what looks crisp in the Canvas viewport with your nose against it.

Step 02Six channels, one material

This is the mental model everything else hangs off. Canvas doesn't have "a texture". It has six independent layer stacks, each compositing over its own neutral base into its own image, all six feeding one material at once.

Two controls make this stack legible while you work:

• Isolate Channel — shows the active channel unshaded, as raw data. This is how you check a roughness map actually has variation in it instead of trusting a glossy highlight.
• Shading in the Scene tab — PBR (lit), Unlit (flat), Matcap (clay). Unlit judges base colour with lighting removed; Matcap reads form and silhouette with texture removed.

Step 03Values that don't lie

PBR is a physical model, and it punishes invented numbers. Albedo that's too dark starves global illumination; metallic that sits at 0.5 describes a material that doesn't exist. The ranges below come from measured references (sourced at the end), translated into what you actually type into Canvas.

Step 04The whole point: smart material layers

This is the feature worth learning Canvas for, and it's two clicks deep in a tab most people never open.

A material layer — added by clicking a card in the Materials tab — is not a flood fill. It creates a linked fill layer in every channel the preset defines, and gives all of them one shared mask, black. Black means hidden. So the material is loaded into all six channels at once, and invisible.

Then you paint the mask, and the entire PBR material appears where you brush — colour, roughness, metalness, all together, with everything under it untouched.

Driving it

• Clicking a material card switches you to its first channel and turns on Edit mask automatically. You are already painting the mask — just start brushing.
• In mask editing, Paint reveals (white) and Erase conceals (black). Everything else still applies: tip shape, hardness, opacity, flow, symmetry.
• Only the channel you're viewing updates live during a drag. Release the mouse and the siblings catch up. Don't chase it — that's by design, not lag.
• Stack them. Rough Stone as a base coat, Brushed Metal masked into the panels, Gold masked into the trim — four coherent PBR value-sets you can reveal independently. Treat each as a primed surface to paint into, not a finished material.

Step 05Wear that reads as history

Uniform grunge looks like noise. Believable wear is positional — it appears where physics puts it. Edges and corners get knocked and rubbed until the material underneath shows through; recesses and crevices collect dust and grime that nothing wipes out.

Canvas computes both from your mesh's own geometry. Edge Wear and Cavity Dirt bake a curvature estimate — comparing each vertex normal against its neighbours — into a UV-space map, then composite your brush colour through it.

The professional move

Don't run Edge Wear directly onto albedo. Add a material layer for the material underneath — bare metal under paint, say — then run Edge Wear into that layer's mask with Edit mask on. Now the worn edges reveal a full PBR material rather than a paler colour: the exposed metal is genuinely metallic and genuinely smoother, because it's a real material showing through, not a lighter shade pretending.

Then break the perfection. Curvature wear applied at full strength wraps every edge evenly, which reads as machine-made. Set the brush to Erase with the Noise (grunge) tip and knock holes in the wear mask so the wear becomes intermittent — heavy where a hand or a crate would actually strike, absent where nothing reaches.

Step 06The brush bench

Eight modes, four tips, and the sliders that decide whether a stroke reads as a stroke or as a surface.

Tips

• Round — radial falloff shaped by Hardness. The default and usually right.
• Square — box falloff. Panel edges, hard-surface masking.
• Airbrush — grainy, centre-weighted, builds up as you pass over it. Soft dust accumulation.
• Noise (grunge) — procedural FBM noise sampled in texture space, driven by Noise scale. The most valuable tip in the program for game textures, because it breaks up anything uniform and never repeats.

The four sliders that matter

Two more worth switching on: Pen pressure (independently to opacity and size) if you have a tablet, and Preset — save a brush you've dialled in, recall it later. A grunge brush you tuned once and named is worth more than any single texture you'll paint with it.

Symmetry, stencils, decals

• Symmetry mirrors across local X, Y, Z — combinable — or radially around an axis. Each mirrored copy re-picks its own UV from the mirrored 3D point, so it works on any UV layout, including atlas-packed ones where the two halves aren't neighbours in texture space.
• Load Stencil… plus Use stencil turns the brush into a stamp shaped by an image. Drag with wide spacing to repeat it.
• Project From View projects that stencil from the current camera onto the surface — the way you get logos, stencilled numbering and poster decals to sit correctly across curvature. Turn on Occlude hidden faces so it doesn't print through to the back.
• Load Decal… then Place Decal gives the same idea with position, size, rotation and opacity you can adjust before committing, with Show placement preview to line it up.

Step 07Let the mesh do the work

Two bakes turn geometry into texture data, and both save hours of hand-painting.

Bake AO casts rays per vertex to measure how occluded each point is, and writes the result into the AO channel. Run it once, early, after your UVs are final. It's synchronous and dense meshes take a moment — that's raytracing, not a hang.

Height → Normal reads the active layer's luminance as a height field and converts it to a tangent-space normal map with a Sobel filter, controlled by Height strength. This is how you get surface relief without sculpting: paint your rivets, panel gaps, scratches and weld beads in grayscale — bright is raised, dark is recessed — then convert. Painting normal maps by hand is a losing game; painting height is intuitive.

Step 08The grime pass that ties it together

This is the last 10% that separates a texture set from a texture. When an asset has three or four materials on it, each individually correct, it still reads as parts bolted together — because nothing has happened to them as one object.

The fix is a single unifying pass on top of everything:

1. 1Add a new layer at the top of the Albedo stack.
2. 2Set its blend mode to Multiply and its opacity low — 10–20%.
3. 3Pick a desaturated, slightly warm dark — the colour of the world's dust, not black.
4. 4Paint with the Noise (grunge) tip at large size across the whole model, ignoring material boundaries entirely.
5. 5Add the same pass to Roughness — dirt is rougher than what it lands on, and this is the half most people skip.

Because it crosses every material boundary, it makes the object read as one thing that has sat in one place. For Ascent of Ashes specifically, this is also where you pull a bright asset back into the game's muted, grounded palette — a warm grey multiply at 15% does more to make a prop belong than any amount of albedo tweaking.

Step 09Judge it honestly

A texture that looks great under one light is a texture you can't ship. The Scene tab exists to stop you fooling yourself.

• Change the light. Cycle the environment presets and the bundled HDRIs — Studio Softbox (HDRI) and Venice Sunset are deliberately different in temperature and contrast. Anything that only works under one of them isn't finished. HDRI rotation sweeps the key light around without changing anything else.
• Turn the lighting off. Unlit (flat) reveals what you've actually painted into albedo. Baked-in highlights are glaring here and invisible in PBR.
• Turn the texture off. Matcap (clay) shows form alone — the check for whether your normal map is doing anything, or lying.
• Check each channel raw. Isolate Channel through all six. Roughness should have visible structure; Metallic should be near-binary; AO should look like contact shadow and nothing else.
• Ground, Shadows and Reflections add contact and environment response — turn Reflections on when judging metal, since metal is almost entirely reflection.

Step 10Ship it

Set Texture resolution in the Scene tab before the final pass — 1024 / 2048 / 4096. Changing it resamples every layer and mask across all channels with Lanczos filtering, but it also clears undo history, so decide before you're deep in.

For an isometric colony sim, 1024 covers most props comfortably and 2048 is generous. Resolution you can't see is GPU cost the player pays for nothing.

ReferenceShortcuts and rescue

Adjust Active Layer… gives brightness, contrast, hue, saturation and invert with live preview — the values apply as you drag and revert cleanly if you cancel, so it's safe to explore. Invert is the quickest fix in the program: a mask that's revealing exactly the wrong areas is one click from correct.