VertexColoredNeuroSurface-class: VertexColoredNeuroSurface

In bbuchsbaum/neurosurf: Data structures and visualization for surface-based neuroimaging data

VertexColoredNeuroSurface

Description

A three-dimensional surface consisting of a set of triangle vertices with one color per vertex.

Details

This class extends NeuroSurface by adding per-vertex coloring functionality. The colors slot contains a vector of hex color codes that define the color for each vertex. Unlike ColorMappedNeuroSurface, this class does not use a colormap or data mapping, but instead directly specifies colors for each vertex.

Slots

geometry

The surface geometry, an instance of SurfaceGeometry

indices

An integer vector specifying the subset of valid surface nodes encoded in the geometry object

colors

A character vector of hex color codes representing the color of each vertex

See Also

view_surface

Examples

# First create a simple tetrahedron mesh
vertices <- c(
  0, 0, 0,
  1, 0, 0,
  0, 1, 0,
  0, 0, 1
)
triangles <- c(
  1, 2, 3,
  1, 2, 4,
  1, 3, 4,
  2, 3, 4
)

# Create mesh3d object
mesh <- rgl::mesh3d(vertices = vertices, triangles = triangles)

# Create a graph representation
edges <- rbind(
  c(1,2), c(1,3), c(1,4),
  c(2,3), c(2,4),
  c(3,4)
)
graph <- igraph::graph_from_edgelist(edges)

# Create a SurfaceGeometry object
geometry <- new("SurfaceGeometry",
               mesh = mesh,
               graph = graph,
               hemi = "left")

# Define indices for all vertices
indices <- 1:4

# Create placeholder data (required by NeuroSurface parent class)
vertex_data <- c(0, 0, 0, 0)  # Not used for coloring

# Define explicit colors for each vertex
vertex_colors <- c(
  "#FF0000",  # Red for vertex 1
  "#00FF00",  # Green for vertex 2
  "#0000FF",  # Blue for vertex 3
  "#FFFF00"   # Yellow for vertex 4
)

# Create the VertexColoredNeuroSurface object
colored_vertices <- new("VertexColoredNeuroSurface",
                       geometry = geometry,
                       indices = indices,
                       data = vertex_data,
                       colors = vertex_colors)

# In this example, each vertex has an explicit color:
# - Vertex 1 is red
# - Vertex 2 is green
# - Vertex 3 is blue
# - Vertex 4 is yellow

bbuchsbaum/neurosurf documentation built on June 10, 2025, 8:22 p.m.