Field 3D Root

Updated: 12 Aug 2025

The root node for a 3D Field system

Method #

This node is the root node and container for any 3D Field system. Field Emitters, Affectors, Colliders, and Rendering nodes should be parented to this node directly or indirectly in order to be operational.

A 3D Field system is built of voxels, tiny 3d pixels which contain various kinds of information such as density, velocity, temperature, and more. Each of these voxels runs a fluid simulation, where the data in each voxel contributes to the how the simulation behaves.

As the Root node, it contains a number of controls that are globally effective across the system, and can have wide ranging effects on the simulation. With Fields in particular, much of the motion and shape of the simulation is derived from the simulation properties, therefore familiarity with the settings below is a must for adept use of a field system.

The simulation of a field is extremely VRAM intensive, and the bounds (set either in the root or input) can be used to constrain that vram usage. The Notch Field system is mostly sparse, meaning that the simulation only processes in voxels which contain density data, with the exception that the velocity simulation has to be run over the full grid bounds. As each voxel contains multiple types of simulation data, the more smoke and density in the voxel grid the slower and more VRAM intensive the simulation can get. Therefore, it’s important to set meaningful bounds (to limit the area the simulation can spread), as well as balance voxel size and simulation quality to maintain reasonable performance.

Parameters

Metrics

These properties display live information about the fields system.

Parameter	Details
Cell Capacity Used	The percentage of voxel cells that are currently being actively calculated.
Memory Allocated For Simulation	The amount of memory allocated for the simulation.
Memory Required For Simulation	The amount of memory currently required for the simulation.

Attributes

These properties control the core behaviours of the node.

Parameter	Details
Solver Mode	Control which simulation solver is used to process the various forces in the field system. Smoke : Multi-level advection solver, for fluid effects like flames and billowing smoke. Cloud : Pyroclastic advection solver, generating detailed and puffier simulations useful for clouds and detailed smoke. Liquid : TBC
Simulation Performance	Controls the balance between performance and accuracy in the simulation. Fast : A performance preset which sacrifices some levels of accuracy in the sim for greatly improved performance. Balanced : A performance preset which tries to find a balance between simulation accuracy and performance. Quality : A performance preset which sacrifices performance for greater accuracy in the simulation. Custom : Expands the internal performance settings for the Field solver for greater control over the simulation settings.
Solver Iterations	How many times the simulation is processed per frame. Higher iterations improve accuracy, but impact performance.
Solver Pre Iterations	TBC
Solver Post Iterations	TBC
Velocity Upsample	How the velocity simulation upscales to apply to the other field data sources.
Vorticity Processing	Controls the area the vorticity simulation is applied to. Filled Areas : Runs the vorticity simulation on only the areas of the voxel grid which contain smoke. Full Grid : Runs the vorticity simulation on the full resolution grid.
Velocity Detail	Select the amount of detail for the velocity calculations.
Bounds Size	Set the maximum size for the field to generate. The Velocity simulation is always run at full grid size, so tightening the bounds to only the area required can improve performance too.
Voxel Size	The size of each voxel in the grid in space.
Velocity Downsample	Reduces the resolution of the velocity simulation, dramatically improving the performance of the simulation but reducing the detail.
Temperatures	Adds temperature as a property into the field simulation. Use Temperature : Calculate temperature in the field simulation. Forces Only : Only calculate forces, and not temperature in the field simulation.
Max Temperature (K)	The maximum temperature allowed in the field simulation
Ambient Temperature (K)	The base temperature of the field simulation
Boyancy	How much boyancy is applied to the field system. Boyancy meaning the tendency to float.
Cooling Rate	How quickly the temperature fades.
Temperature -> Expansion	Set to what effect the temperature in the system adds to the amount of expansion.
Gravity	How much gravity is applied to the field system. Gravity being a downward force.
Density Diffusion	Diffuses the density which will result in a less defined and more “blurred” simulation.
Temperature Diffusion	Diffuses the temperature which will “blur” the detail in the temperature.
Density Dissipation	How fast the density dissipates to 0.
Velocity Dissipation	How fast the velocity dissipates to 0.
Combustion	TBC Temperature Only : TBC Fuel + Temperature : TBC
Combustion Heat Rate	TBC
Combustion Burn Rate	TBC
Emitter Colours	TBC No Colour Channel : TBC Per-Emitter Colours : TBC
Simulation Time Step	What rate to update the simulation. Playback Rate : Update the simulation once per playback frame. Locked : Update the simulation at a set rate, separate from the main playback rate.
Simulation FPS	Set the target simulation update rate when “Simulation Time Step” is locked.
Max Steps Per Frame	The maximum amount of simulation updates allowed per each playback frame.
Advect Mode	Method by which the advection of properties from one cell to another is calculated. Mck 1 : More detail but a bit slower. Using 1 Runge-Kutta iteration. Mck 4 : More detail but a bit slower. Using 4 Runge-Kutta iterations. Simple 1 : Faster but less detail. Using 1 Runge-Kutta iteration. Simple 4 : Faster but less detail. Using 4 Runge-Kutta iterations.
Velocity Advect Mode	Method by which the advection of velocity from one cell to another is calculated. Mck 1 : More detail but a bit slower. Using 1 Runge-Kutta iteration. Mck 4 : More detail but a bit slower. Using 4 Runge-Kutta iterations. Simple 1 : Faster but less detail. Using 1 Runge-Kutta iteration. Simple 4 : Faster but less detail. Using 4 Runge-Kutta iterations.
Advection Factor	Used to blend in the amount of advection.
Vorticity	TBC
Large Vorticity	TBC
Temperature Vorticity	Uses temperature’s magnitude to modulate the vorticity.
Velocity Vorticity	Uses velocity’s magnitude to modulate the vorticity.
UVs	Does the field system generate UVs. Off : Do not generate UVs. Generate UVs : Generate UVs.
Max VRAM Usage (Pct)	The maximum percentage of the VRAM that the field system can reserve.
Bake Now..	Cache the field system to file.

Inputs

Name	Description	Typical Input
Bounding Box	Bounding box input to define boundary of field system.	Bounding Box
Transform Modifiers	Apply the transforms of another node to this node.	Null
Target Node	Modifiy the rotations of the node to always direct the z axis towards the input.	Null
Local Transform Override	Apply the transforms of another node to this node, relative to its parent.	Null