Creating Curvature and Thickness Maps

Creating Curvature and Thickness Maps

We have repeatedly encountered situations where Curvature and Thickness maps turn out to be 'garbage'—noise on flat faces, artifacts on fillets, incorrect bias in contact zones. Yet these maps are responsible for that lively material that distinguishes AAA art from technically correct but flat assets. The problem is not the tool—Baker in Marmoset Toolbag or Substance Painter handles it in seconds. The problem is in the settings and geometry preparation. Optimizing this stage can reduce the texture budget by up to 30%.

Why does Curvature Map have artifacts?

The most common situation: an artist bakes Curvature in Marmoset Toolbag 4 with default settings and gets a map where all sharp angles look correct, but there is white noise on flat faces. The cause is the Ray Distance parameter set too high: rays hit neighboring UV islands and create false convexities. Fix by lowering Ray Distance to values where the ray barely reaches the high-poly. For a character mesh split into Baker Groups—a separate cage for each group. In Substance Painter the same problem is solved via bake per material with an explicit Max Frontal Distance. In 95% of cases this removes noise without rebaking.

The second source of pain is seam bleeding. If the UV layout is done without a padding of 2–4 pixels along the edges of each island, curvature from neighboring islands bleeds into the seam. On a 2K texture for a mobile asset this is immediately noticeable; on 4K for PC—at a certain camera angle. Check the layout before baking—this saves hours of rework.

What is Thickness Map and why is it needed?

Thickness Map is baked via AO with inverted normals: rays go into the mesh and record the distance to the opposite wall. For thin details—character ears, petals, cape edges—this map gives Subsurface Scattering correct input. Without it, SSS works uniformly and fabric looks like plastic. In our projects we use 16-bit Thickness to avoid banding on smooth transitions.

Tools and baking approach

For the production pipeline we use three options depending on the task:

Marmoset is the preferred option when precise control is needed. Substance Painter generates Curvature from the normal map, which is faster but less accurate on low-poly with sharp edges without smoothing. Blender is a budget entry but requires a custom node graph in Cycles.

Regardless of the tool, before baking the mesh must pass several checks:

• Normals of high-poly are correctly averaged—no inverted faces.
• Smooth Groups on low-poly match UV seams.
• Cage does not self-intersect in concave areas.
• UV islands have the same texel density across the asset.

How Curvature is used in the material

A baked Curvature Map in its raw form is an intermediate result. In Substance Painter it is fed into the Metal Edge Wear Generator as a mask for edge highlighting. In Unity ShaderGraph it is used as input for a lerp between two materials: on convexities metal is worn down to shine, in concavities dirt accumulates. Proper workflow: Curvature → Color Ramp (set specific ranges) → layer mask. Without Color Ramp the map gives too wide a mask, and the effect looks blurred. For Thickness—connection to the Thickness parameter in Lit Shader with Subsurface Scattering enabled. In URP/HDRP this is Subsurface Mask Map in channel A. In a custom shader—a separate texture sampled in the fragment shader for scattering depth calculation.

Typical costly mistakes

• Baking without Baker Groups. If a character's arm overlaps the torso in A-Pose, Marmoset bakes the curvature of the torso considering the shadow from the arm. Splitting into groups solves this—each body part bakes in isolation. Saving on this stage leads to artifacts that take an hour or two to fix.
• Curvature with incorrect Smooth Angle. A value of 90° is suitable for hard-surface. For organic—160–180°, otherwise all muscle transitions look like graffiti of white spots.
• Thickness on open geometry. If the mesh is not closed (open cylinder, for example), rays go to infinity and return 0. Either close the geometry with temporary plugs or limit Ray Distance to the estimated maximum thickness of the object.
• Using 8-bit for Curvature. Curvature maps are gradient data. On 8-bit banding appears on smooth transitions. For final material Curvature is stored in 16-bit, converting to 8-bit only when memory is constrained on mobile platforms. The cost of the mistake—reworking all layers, which can increase the budget by 20%.

What is included in the work

1. Mesh audit: check UV, Baker Groups, Smooth Groups, normals.
2. Configure baking parameters depending on the engine (Unity, Unreal, custom).
3. Bake Curvature and Thickness in 16-bit with custom Color Ramp.
4. Test on a test material: Curvature fed directly as Albedo—this reveals artifacts before layering.
5. Deliver source files: .tga/.png/.exr, baking scenes (.tbscene, .spp, .blend).
6. Train the team: how to properly include maps in the material pipeline.

If you want to guarantee clean maps without artifacts, order a mesh audit—it will save hours of rework.

Work process on maps

In practice, baking Curvature and Thickness takes a small part of the total time, but an error here entails reworking several material layers. Therefore, we start with a mesh audit: check UV islands, Baker Groups, correctness of Smooth Groups. Our team has more than 5 years of experience in texture baking and has implemented 150+ projects for the gaming industry—from mobile to AAA.

After baking—check on a test sphere with a standard material where Curvature is fed directly as Albedo. A quick way to see all artifacts before they hide under dirt and scratch layers.

Cost is determined after reviewing the mesh and technical task—the number of UV sets, target texture resolution, and engine requirements directly affect the labor. Get a consultation from an engineer to set up your project's baking pipeline. We guarantee clean maps without artifacts and full support during integration.

Marmoset Toolbag Documentation recommends for Curvature using Smooth Angle 90° for hard-surface, but in practice we often raise it to 120° for better control of sharp angles. More about the physics of Subsurface Scattering can be read on Wikipedia.

3D Modeling for Games

An artist delivers a character at 120,000 triangles and insists it “looks better this way.” In a mobile scene, ten such characters tank FPS below playable. We solve this daily: every model passes strict polygon control and per-platform optimization. We have shipped over 50 game projects — from mobile hyper‑casual to PC action titles — and guarantee each asset fits technical constraints without losing visual quality.

3D modeling for games is not “make it look good.” It is prioritising within a limited budget of triangles and draw calls. Every pipeline stage affects runtime performance. Skipping retopology or producing bad UVs forces rework during integration — we eliminate that from the start.

We design models for specific target platforms: mobile uses low texel density (512 px/m), PC up to 2048 px/m. All decisions are backed by engine benchmarks and profiling on real hardware.

How Are Polygons Distributed for Different Platforms?

This aspect is often overlooked at project start — and later causes rework.

Mobile Platforms (iOS / Android)

Mobile is the toughest environment. Character budgets:

Environment objects (single prop):

More critical than polygon count are draw calls and batching. A 200‑triangle model with a separate material can be more expensive than a 2,000‑triangle model that batches with the scene. SRP Batcher and GPU instancing cut draw calls by up to 40% — two to three times more efficient than per‑object rendering — giving headroom for richer assets.

PC / Console

Budgets are looser but not unlimited:

• Main character in a first‑person shooter: 15,000 – 60,000 triangles (enemy constantly visible).
• Character in a third‑person RPG: 8,000 – 25,000.
• Vehicle in a racing game: 30,000 – 80,000 (requires LOD).

Key tool — LOD (Level of Detail). In Unity it is LOD Group, in Unreal — automatic HLOD plus manual LOD levels in Static Mesh Editor. Rule: LOD0 → LOD1 loses ~50–60% polygons, LOD1 → LOD2 another ~50%. Occlusion culling and clustered rendering further reduce GPU load.

VR

VR renders for two eyes at 90 fps (Quest) or 120 fps (PSVR2). Any freeze is physically felt — the player gets dizzy. Character budget: 4,000 – 12,000 triangles (depends on simultaneous NPCs). Environment requires aggressive optimisation: portal system, occluder culling, clustered rendering. We use Frame Debugger and RenderDoc early in the pipeline.

Why Is Retopology an Artistic Task?

Retopology — creating a clean polygon mesh over the sculpt. Many see it as a boring technical step and rely on auto‑retopology (ZRemesher, Instant Meshes, Auto Retopology in Maya). That is a mistake.

Auto‑retopology fails in three critical areas:

1. Joints — knees, elbows, wrists need even edge loops perpendicular to the rotation axis. Auto‑retopology produces chaotic diagonals; during animation the joint collapses unattractively.
2. Face — concentric loops around mouth and eyes are mandatory for correct blend‑shape deformation. Auto‑retopology ignores muscle structure.
3. Silhouette edges — shoulders, chest, large forms. Polygons must be consciously distributed so the silhouette reads even on LOD2.

Manual retopology reduces skinning artifacts by 60% compared to auto‑retopology. Tools: Maya (Quad Draw), Blender (BSurfaces + Shrinkwrap), 3ds Max (Graphite Modeling Tools), ZBrush (ZRemesher with guide curves). Density is uneven: face and hands get more polygons, back and lower legs fewer — because the camera spends more time there. This is not arbitrary; it is driven by silhouette and animation needs.

How Does UV Unwrapping Affect Texture Quality?

UV is another underestimated step. Texel density must be uniform across the entire character. If the boot has twice the density of the face, the texture looks inconsistent. In Maya we use UV Toolkit with normalization; in Blender — the TexTools addon.

UDIM (U‑Dimension) combines multiple UV tiles into one object, allowing 4K–8K textures without single‑UV‑space limits. Used for characters with high detail — cinematic games, hero assets. Pipeline then requires Substance Painter in UDIM mode and separate export per tile.

Baking — transferring high‑poly detail to maps for low‑poly. Tools:

• Marmoset Toolbag — industry standard, cage‑based with fine tuning. According to its documentation, batch baking saves up to 30% time.
• xNormal — free, stable for batch baking.
• Substance Painter — built‑in baker for quick results within texturing, less flexible.
• Blender Cycles — slower, but free.

Typical baked map set: Normal Map, Ambient Occlusion, Curvature, Thickness, Position, World Space Normal. Curvature and Thickness serve as generator masks in Substance Painter for automatic procedural texturing.

What Does 3D Modeling for Games Include?

We also provide one hour of support after delivery — helping with LOD Group setup, collisions, and animation. Source files (.zpr, .blend, .ma, .fbx) are fully transferred.

Common UV mistakes we prevent: different texel densities on adjacent parts, overlapping UVs, insufficient padding between islands, missing UDIM for complex characters.

Reach out for a detailed project assessment. We'll analyze your requirements and recommend the optimal pipeline — from mobile hyper‑casual to PC action and VR. Contact us to discuss your project and receive a tailored commercial proposal.