Vertex Color & Materials

Vertex Color & Materials

OxyBrush includes a high-performance vertex color painting system (polypainting). Because color is stored directly on the 3D vertices, you can paint high-detail color, skin tones, and weathering on your sculpt without having to unwrap UV coordinates first.

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Vertex Painting (Polypaint)

When working on high-density meshes (Levels 3 through 6), vertex density is high enough to support crisp painted details such as iris patterns, lip gradients, tattoos, and metallic scratches.

Activating the Paint Tool

1. Select the Paint Brush from the toolbar.
2. In the Color panel, select your primary painting color using the color wheel, RGB sliders, or HEX input.
3. Stroke directly across the 3D mesh surface to deposit color.

Paint Brush Parameters

• Opacity / Flow: Controls color saturation and transparency per brush dab.
• Blending Modes:
  • Normal / Mix: Replaces existing vertex colors based on opacity.
  • Multiply: Darkens underlying colors; ideal for adding grime, dirt, or ambient shadows.
  • Add / Screen: Lightens underlying colors; ideal for highlights and emissive glows.
• Color Jitter: Adds subtle hue, saturation, and value variations to each dab, producing organic, non-uniform skin tones.

Global Color Actions

• Fill Object: Fills the entire active mesh with the currently selected foreground color.
• Fill Masked: Fills only the unmasked regions with the foreground color.

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Cavity & Peak Tinting (Weathering & Drybrushing)

OxyBrush can procedurally tint your model based on surface curvature:

1. Open the Color panel and click Curvature Tinting.
2. Cavity Color (Dirt / Wash): Select a dark tone (e.g., deep warm brown or dark grey). Adjust the Cavity Threshold slider. The color automatically settles into pores, wrinkles, and deep recesses, mimicking an ink wash or oil wash.
3. Peak Color (Drybrush / Edge Wear): Select a lighter tone (e.g., ivory bone or metallic silver). The color highlights sharp outer ridges, simulating edge wear or traditional miniature drybrushing.
4. Click Apply to Vertex Colors to bake the effect permanently into the vertex color buffer.

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Shading & Material Settings

Vertex colors can be viewed under multiple shading environments:

Mode	Appearance	Best Used For
Matcap + Vertex Color	Blends vertex colors multiplicatively or additively with the active Matcap.	Evaluating color contrast while retaining strong surface volume.
Flat Color (Unlit)	Pure albedo color with zero lighting, reflections, or shadows.	Checking base color values for game assets before baking.
PBR Preview	Roughness, metallic, and ambient directional lighting.	Previewing how the sculpt will appear in game engines like Unreal Engine or Unity.

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Exporting Painted Meshes

Vertex colors are natively saved into project files (.oxy) and can be exported to standard 3D formats:

• glTF 2.0 / GLB: Vertex colors are exported in the standard COLOR_0 attribute buffer. Fully supported by Blender, Unreal Engine, Unity, Godot, and Three.js.
• PLY (Polygon File Format): Standard format for full-color 3D printing and 3D scanning software.
• OBJ: Exports extended v X Y Z R G B vertex color lines, compatible with ZBrush and Maya.
• Color STL: Compatible with multi-material 3D printers and slicing software supporting per-vertex vertex colors.