Rendering Types

Volvicon provides multiple rendering methods to visualize 3D data. Each method is suited for different data types and visualization goals.

Volume Rendering

Volume rendering displays the entire 3D volume image by assigning colors and opacity to intensity values. It allows you to see through the data and visualize internal structures.

How it Works

1. Each voxel is assigned a color and opacity based on its intensity
2. Rays are cast through the volume from the viewer's perspective
3. Colors and opacities are accumulated along each ray
4. The result shows a semi-transparent 3D view of the data

Transfer Function

The transfer function controls how intensities are mapped to visual properties:

Component	Description
Color	Assigns colors to intensity ranges
Opacity	Controls transparency (0 = invisible, 1 = solid)
Gradient	Uses intensity changes to highlight edges

Use Cases

• Visualizing internal structures without cutting
• Showing density variations within objects
• Medical imaging (CT, MRI visualization)
• Material inspection

Advantages

• Shows entire volume at once
• Reveals internal features
• No surface extraction required

Limitations

• Computationally intensive
• Requires careful transfer function setup
• Can be difficult to interpret dense data

Surface Rendering

Surface rendering displays surface meshes as solid objects with lighting and shading. It provides a clear view of object boundaries.

How it Works

1. Surface mesh defines the object boundary
2. Lighting calculations determine brightness based on surface orientation
3. Faces are shaded to create a 3D appearance

Shading Options

Set Shading interpolation: in the surface material properties:

Option	Description
None	No shading is applied; the surface is drawn in its flat base color
Flat	Each face has a uniform color, so individual triangles stay visible (default)
Gouraud	Color is interpolated across each face, giving a smooth appearance
Phong	Lighting is computed per pixel, giving the smoothest highlights
Physically-based rendering	Lighting is computed from physical material properties, and enables the Roughness: and Metallic: settings

Material Properties

Property	Description
Material color	The Ambient color:, Diffuse color:, and Specular color: of the surface
Ambient:	Strength of the uniform lighting component, in percent
Diffuse:	Strength of the light scattered in all directions, in percent
Specular:	Strength of the shiny highlights, in percent
Shininess:	How tight the specular highlight is
Opacity	Transparency of the surface, in percent

Use Cases

• Viewing segmented structures
• 3D printing preview
• CAD-style visualization
• Presentation and reporting

Advantages

• Clear, easy-to-interpret images
• Fast rendering
• Familiar 3D appearance

Limitations

• Shows only surfaces, not interior
• Requires surface mesh generation
• Complex internal structures may occlude each other

Volume Mesh Rendering

Volume mesh rendering displays tetrahedral or hexahedral meshes used for simulation. It can show the mesh structure or simulation results.

Display Modes

Mode	Description
Solid	Filled elements with lighting
Wireframe	Only edges visible
Points	Only nodes visible
Surface only	Shows outer boundary

Visualization Options

Option	Description
Element quality	Color by mesh quality metrics
Scalar field	Color by simulation results (stress, temperature)
Clipping	Cut away portions to see interior
Shrink	Reduce element size to see structure

Use Cases

• Inspecting mesh quality before simulation
• Visualizing FEA/CFD results
• Debugging mesh generation

Comparing Rendering Types

Aspect	Volume Rendering	Surface Rendering	Volume Mesh Rendering
Data type	Volume image	Surface mesh	Volume mesh
Shows interior	Yes	No	With clipping
Performance	Slower	Fast	Medium
Typical use	Exploration	Presentation	Simulation

Related Topics

• Volume Grayscale Image – Data for volume rendering
• Surface Mesh – Data for surface rendering
• Volume Mesh – Data for volume mesh rendering