Enumeration: RenderingMode

• DVR = "DVR"

Direct Volume Rendering
DVR stands for Direct Volume Rendering, which is the classic volume rendering mode.
In this mode, the volume is rendered by raycasting, accumulating the voxels values along the ray path, taking into account the voxel sample opacity.
Once the ray's accumulated voxel samples reach full opacity, the ray do not travel further.
The voxels opacity is affected by the transfer function, to give users full control over the values transparency.

• DVRValueAsAlpha = "DVRValueAsAlpha"

Direct Volume Rendering with value of volume for opacity
This mode stands for Direct Volume Rendering using voxel value as alpha.
Similarly to the regular DVR mode, the volume is rendered by raycasting, accumulating the voxels values along the ray path, taking into account the voxel sample opacity.
The main difference is in this mode, the value themselves are used for opacity. The stronger the value, the more opaque the voxel. This is the legacy behavior in classic CT scan volume renderers.

• MIP = "MIP"

Maximum Intensity Projection
MIP stands for Maximum Intensity Projection.
In this mode, the fragment color is determined by the voxel with maximum intensity value along the ray.
This mode is classic in CT scan visualisation, where the data represent density value, so the data can be better visualized by favoring higher density values.
To enable fine control over which value is prioritized, please instead use MIP_CUSTOM.

• MIPCustom = "MIPCustom"

Customized Maximum Intensity Projection
This mode is implemented based on MIP mode, but offers more freedom for user to use transfer function to control the result.
Instead of prioritizing voxels with the highest value, it use the transfer function's opacity to determine the value to prioritize.

• Surface = "Surface"

Iso 'Surface' Rendering
In stead of actually generated surface, this mode will cast a ray from camera and render the first voxel within up to four ranges specified by user.
The ranges can be set from option surfaceranges. By default, for each range, the min of the range is set as datamin, the max of the range is set as datamax.
Because of the nature of Surface mode, enabling the Volume rendering Lighting can improve the visual result, but the performances will be affected.