volume

volume(volume_data)
volume(x, y, z, volume_data)

Plots a volume, with optional physical dimensions x, y, z. Available algorithms are:

  • :iso => IsoValue

  • :absorption => Absorption

  • :mip => MaximumIntensityProjection

  • :absorptionrgba => AbsorptionRGBA

  • :additive => AdditiveRGBA

  • :indexedabsorption => IndexedAbsorptionRGBA

Attributes

Specific to Volume

  • algorithm::Union{Symbol, RaymarchAlgorithm} = :mip sets the volume algorithm that is used.

  • isorange::Real = 0.05 sets the range of values picked up by the IsoValue algorithm.

  • isovalue = 0.5 sets the target value for the IsoValue algorithm.

  • interpolate::Bool = true sets whether the volume data should be sampled with interpolation.

3D shading attributes

  • shading = Makie.automatic sets the lighting algorithm used. Options are NoShading (no lighting), FastShading (AmbientLight + PointLight) or MultiLightShading (Multiple lights, GLMakie only). Note that this does not affect RPRMakie.

  • diffuse::Vec3f = Vec3f(1.0) sets how strongly the red, green and blue channel react to diffuse (scattered) light.

  • specular::Vec3f = Vec3f(0.4) sets how strongly the object reflects light in the red, green and blue channels.

  • shininess::Real = 32.0 sets how sharp the reflection is.

  • backlight::Float32 = 0f0 sets a weight for secondary light calculation with inverted normals.

  • ssao::Bool = false adjusts whether the plot is rendered with ssao (screen space ambient occlusion). Note that this only makes sense in 3D plots and is only applicable with fxaa = true.

Color attributes

  • colormap::Union{Symbol, Vector{<:Colorant}} = :viridis sets the colormap that is sampled for numeric colors. PlotUtils.cgrad(...), Makie.Reverse(any_colormap) can be used as well, or any symbol from ColorBrewer or PlotUtils. To see all available color gradients, you can call Makie.available_gradients().

  • colorscale::Function = identity color transform function. Can be any function, but only works well together with Colorbar for identity, log, log2, log10, sqrt, logit, Makie.pseudolog10 and Makie.Symlog10.

  • colorrange::Tuple{<:Real, <:Real} sets the values representing the start and end points of colormap.

  • nan_color::Union{Symbol, <:Colorant} = RGBAf(0,0,0,0) sets a replacement color for color = NaN.

  • lowclip::Union{Nothing, Symbol, <:Colorant} = nothing sets a color for any value below the colorrange.

  • highclip::Union{Nothing, Symbol, <:Colorant} = nothing sets a color for any value above the colorrange.

  • alpha = 1.0 sets the alpha value of the colormap or color attribute. Multiple alphas like in plot(alpha=0.2, color=(:red, 0.5), will get multiplied.

Generic attributes

  • visible::Bool = true sets whether the plot will be rendered or not.

  • overdraw::Bool = false sets whether the plot will draw over other plots. This specifically means ignoring depth checks in GL backends.

  • transparency::Bool = false adjusts how the plot deals with transparency. In GLMakie transparency = true results in using Order Independent Transparency.

  • fxaa::Bool = true adjusts whether the plot is rendered with fxaa (anti-aliasing).

  • inspectable::Bool = true sets whether this plot should be seen by DataInspector.

  • depth_shift::Float32 = 0f0 adjusts the depth value of a plot after all other transformations, i.e. in clip space, where 0 <= depth <= 1. This only applies to GLMakie and WGLMakie and can be used to adjust render order (like a tunable overdraw).

  • model::Makie.Mat4f sets a model matrix for the plot. This replaces adjustments made with translate!, rotate! and scale!.

  • space::Symbol = :data sets the transformation space for box encompassing the volume plot. See Makie.spaces() for possible inputs.

Examples

using GLMakie
r = LinRange(-1, 1, 100)
cube = [(x.^2 + y.^2 + z.^2) for x = r, y = r, z = r]
contour(cube, alpha=0.5)

cube_with_holes = cube .* (cube .> 1.4)
volume(cube_with_holes, algorithm = :iso, isorange = 0.05, isovalue = 1.7)

using NIfTI
brain = niread(Makie.assetpath("brain.nii.gz")).raw
mini, maxi = extrema(brain)
normed = Float32.((brain .- mini) ./ (maxi - mini))

fig = Figure(size=(1000, 450))
# Make a colormap, with the first value being transparent
colormap = to_colormap(:plasma)
colormap[1] = RGBAf(0,0,0,0)
volume(fig[1, 1], normed, algorithm = :absorption, absorption=4f0, colormap=colormap, axis=(type=Axis3, title = "Absorption"))
volume(fig[1, 2], normed, algorithm = :mip, colormap=colormap, axis=(type=Axis3, title="Maximum Intensity Projection"))
fig