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Common page

Every operator that outputs a volume has a Common page with the same parameters. They are described here once; operator pages link here instead of repeating them.

8-bit by default

Pixel Format defaults to Use Input. An operator with nothing connected to its first input resolves that to 8-bit fixed (RGBA): values are clamped to 0–1 and quantised in steps of 1/255, and every operator downstream inherits the format. Set a float format at the start of a chain that carries signed distances, densities above 1, velocities or positions.

Parameters - Common Page

Output Resolution Outputresolution ⊞ - Where the output's width, height and depth come from. With nothing connected to the first input the operator always uses Resolution, whichever option is set. Menu · default Use Input

  • Use Input useinput - The first input's width, height and depth.
  • Custom custom - The Resolution parameter.

Resolution Resolution1 Resolution2 Resolution3 ⊞ - Width, height and depth of the output in voxels. Used when Output Resolution is Custom, or when the first input is not connected. Memory is width × height × depth × bytes per voxel of the Pixel Format: 256³ at 16-bit float RGBA is 128 MiB. Int × 3 · default 64

Input Smoothness Inputfiltertype ⊞ - Filtering of the internal GLSL TOPs' input samplers, as TouchDesigner's Input Smoothness. Inputs are read at normalised coordinates, so this matters whenever the input and output resolutions differ or an input is transformed. Nearest Pixel returns voxels unblended; Interpolate Pixels is trilinear. Menu · default Interpolate Pixels

  • Nearest Pixel nearest
  • Interpolate Pixels linear
  • Mipmap Pixels mipmap

Passes Npasses - Has no effect on this operator: its shaders are compute shaders, which read the connected input on every pass, so extra passes repeat identical work. Leave it at 1. Int · default 1

Pixel Format Format ⊞ - Pixel format of the output. Use Input takes the first input's format. With nothing connected, Use Input resolves to 8-bit fixed (RGBA), which clamps values to 0–1 and quantises them to 1/255: set a float format for signed distances, densities above 1, velocities or anything else outside 0–1. Menu · default Use Input

Bypass Bypass - Passes the first input through unchanged and skips the operator's work. With nothing connected the output is a single black voxel. Toggle · default Off

Version Version - T3D version of this operator. Read-only information; include it when reporting a problem. Str

Passes

Whether Passes does anything depends on the operator. Measured, it repeats the operation on its own result in add, composite, cross, difference, displace, edge, lookup, matte, multiply, optical_flow, remap, slope, subtract, threshold, top_to. In the other operators every shader stage is a compute shader, which reads the connected input on every pass, so extra passes cost time and change nothing.

Memory

A volume holds width × height × depth voxels, so memory grows with the cube of the resolution:

Resolution 8-bit RGBA 16-bit float RGBA 32-bit float RGBA
64³ 1 MiB 2 MiB 4 MiB
128³ 8 MiB 16 MiB 32 MiB
256³ 64 MiB 128 MiB 256 MiB
512³ 512 MiB 1 GiB 2 GiB

Single-channel formats (Mono) take a quarter of the RGBA figure.