Colorize

The Colorize tool applies color information to surface geometry, enabling visual differentiation of regions, preparation for colored exports, and enhanced visualization. Colors can be applied to selected regions or entire surfaces using various coloring methods.

Overview

Surface colorization adds per-vertex or per-triangle color data to the mesh. This color information:

• Persists with the surface: Colors are stored as part of the mesh data
• Exports with the model: Supported formats (PLY, OBJ, VRML, etc.) include color data
• Enables visualization: Distinguishes regions for analysis and presentation
• Supports selective coloring: Apply colors to specific regions using ROI selection

Common applications include:

• Region marking: Identifying areas of interest with distinct colors
• Export preparation: Adding color for 3D printing or visualization
• Analysis visualization: Permanent color mapping for documentation
• Communication: Highlighting specific features for review

Accessing the Tool

Navigate to the Surface ribbon tab and locate Colorize in the Analyze section. Select a surface object before activating the tool.

Target Selection

Target Object(s)

Select which surface(s) to colorize:

• Active surface: Apply color to the currently active surface only
• All surfaces: Apply color to all surfaces in the project
• Visible surfaces: Apply color to all currently visible surfaces

Region of Interest (ROI)

Use the integrated ROI selection tools to colorize specific regions:

• No selection: Color is applied to the entire surface
• With selection: Color is applied only to selected triangles/points

ROI tools include brush selection, rectangle selection, and other standard selection methods.

Colorization Methods

Three methods are available for applying colors:

Color Selection

Apply a single, user-defined color to the selected region or entire surface.

Parameters:

• Color: Click the color button to open a color picker and select the desired color

This method is ideal for:

• Marking specific regions with identifying colors
• Preparing models with uniform color for export
• Creating visual distinctions between areas

Normal Map

Apply colors based on the surface normal direction at each point or triangle.

The normal map converts the XYZ components of the surface normal to RGB colors:

• X component → Red channel
• Y component → Green channel
• Z component → Blue channel

This visualization reveals:

• Surface orientation patterns
• Normal direction distribution
• Curvature and feature characteristics

Normal map coloring is useful for:

• Visualizing surface orientation
• Quality inspection of normal directions
• Understanding surface topology

Point Coordinates Map

Apply colors based on the spatial position of each point.

The coordinate map converts XYZ positions to RGB colors:

• X position → Red channel
• Y position → Green channel
• Z position → Blue channel

Colors are normalized across the surface extent, creating a gradient that shows spatial distribution.

This visualization helps with:

• Understanding spatial organization
• Identifying position-based patterns
• Debugging coordinate systems

Color Application Target

Choose where colors are stored:

Points (Vertices)

Colorize apply on: Points

Colors are assigned to mesh vertices:

• Produces smooth color gradients across triangles
• Interpolates between vertex colors within triangles
• More natural appearance for most applications
• Standard vertex color approach

Triangles (Faces)

Colorize apply on: Triangles

Colors are assigned to individual triangles:

• Each triangle has uniform color
• Produces a faceted color appearance
• Useful when per-triangle identification is needed
• Shows mesh structure through coloring

Actions

Apply

Click Apply to apply the current colorization settings to the surface. The colors are immediately visible and stored with the mesh data.

Clear

Click Clear to remove all color information from the surface, returning it to the default appearance. This removes both vertex and triangle colors.

Practical Workflows

Marking Regions of Interest

1. Activate the Colorize tool
2. Select "Color selection" method
3. Choose a distinctive color
4. Use ROI tools to select the region of interest
5. Click Apply
6. Repeat with different colors for additional regions

Preparing for Colored Export

1. Apply colors to all desired regions
2. Verify appearance in the 3D view
3. Export using a format that supports colors (PLY, OBJ, etc.)
4. Colors will be included in the exported file

Visualizing Surface Orientation

1. Select "Normal map" method
2. Choose Points for smooth visualization
3. Click Apply
4. Analyze the color patterns to understand normal distribution

Creating Multi-Colored Models

1. First, apply a base color to the entire surface
2. Then select specific regions with ROI tools
3. Apply different colors to each selected region
4. Build up a multi-colored model progressively

Technical Considerations

Color Data Storage

Colors are stored as RGB values (0-255 per channel) at either:

• Vertices: Each vertex stores one color; triangles interpolate
• Triangles: Each triangle stores one color; uniform per-face

The storage location affects both visualization and export.

Export Compatibility

Color data export depends on format support:

Format	Vertex Colors	Face Colors
PLY	✓	✓
OBJ (MTL)	Limited	Via materials
STL	✗	✗
VRML	✓	✓
3MF	✓	✓

Check format documentation for specific color support details.

Multiple Color Operations

Colors can be layered or replaced:

• Applying new colors overwrites existing colors in the target region
• Non-selected regions retain their existing colors
• Use Clear to reset before starting fresh

Rendering Interaction

Colorized surfaces interact with rendering settings:

• Lighting affects the perceived color
• Render properties may override or blend with applied colors
• Preview may differ from exported appearance

Common Issues and Solutions

Issue	Likely Cause	Solution
Colors not visible	Render properties overriding	Check surface render settings
Colors not exporting	Unsupported format	Use PLY or other color-supporting format
Unexpected color pattern	Wrong method selected	Verify colorization method selection
Only partial surface colored	ROI selection active	Clear selection or select entire surface
Colors look different after export	Format color handling	Verify format supports vertex/face colors
Clear not removing colors	Multiple color layers	May need to Clear multiple times or re-import