Field 3D Root
Updated: 12 Aug 2025
The root node for a 3D Field system
Field 3D Root
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
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.
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 over time.
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 calculation.
Density Dissipation
How fast the density dissipates to 0.
Velocity Dissipation
How fast the velocity dissipates to 0.
Combustion
Combustion is a reaction that creates temperature and light in the simulation.
- Temperature Only : Combustion is only calculated using temperature. So adding fuel to the simulation will not have an effect on the amount of combustion.
- Fuel + Temperature : Combustion is calculated using the temperature and fuel, so you can inject fuel into the simulation to increase combustion.
Combustion Heat Rate
Controls the rate at which heat created by combustion is advected from cell to cell.
Combustion Burn Rate
The rate at which the heat from combustion will burn out and cool down.
Emitter Colours
Set whether emitters can add colour to the simulation.
- No Colour Channel : Emitters cannot add colour.
- Per-Emitter Colours : Each emitter can add colour to the simulation independently.
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. Advection is how values are moved from one cell to another.
- 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. Advection is how values are moved from one cell to another.
- 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. Advection is how values are moved from one cell to another.
Vorticity
Vorticity is the amount of “spinning motion” applied to the simulation at any specific point.
Large Vorticity
Large Vorticity is applied on a larger scale than “Vorticity” but also refers to the amount of spinning motion applied across the simulation.
Temperature Vorticity
Uses the temperature’s magnitude to modulate the vorticity. Where there is higher temperature there will be more “spinning motion” applied to the simulation.
Velocity Vorticity
Uses the velocity’s magnitude to modulate the vorticity. Where there is higher velocity there will be more “spinning motion” applied to the simulation.
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.
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.
The properties control the time at which the node is active. See Timeline for editing time segments.
Parameter Details Duration
Control the duration of the node’s time segment.
- Composition Duration : Use the length of the composition for the node’s time segment duration.
- Custom : Set a custom duration for the node’s time segment.
Node Time
The custom start and end time for the node.
Duration (Timecode)
The length of the node’s time segment (in time).
Duration (Frames)
The length of the node’s time segment (in frames).
Time Segment Enabled
Set whether the node’s time segment is enabled or not in the Timeline.
Inputs
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.
|
| Simulation Performance |
Controls the balance between performance and accuracy in the simulation.
|
| 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.
|
| 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.
|
| 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 over time. |
| 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 calculation. |
| Density Dissipation | How fast the density dissipates to 0. |
| Velocity Dissipation | How fast the velocity dissipates to 0. |
| Combustion |
Combustion is a reaction that creates temperature and light in the simulation.
|
| Combustion Heat Rate | Controls the rate at which heat created by combustion is advected from cell to cell. |
| Combustion Burn Rate | The rate at which the heat from combustion will burn out and cool down. |
| Emitter Colours |
Set whether emitters can add colour to the simulation.
|
| Simulation Time Step |
What rate to update the simulation.
|
| 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. Advection is how values are moved from one cell to another.
|
| Velocity Advect Mode |
Method by which the advection of velocity from one cell to another is calculated. Advection is how values are moved from one cell to another.
|
| Advection Factor | Used to blend in the amount of advection. Advection is how values are moved from one cell to another. |
| Vorticity | Vorticity is the amount of “spinning motion” applied to the simulation at any specific point. |
| Large Vorticity | Large Vorticity is applied on a larger scale than “Vorticity” but also refers to the amount of spinning motion applied across the simulation. |
| Temperature Vorticity | Uses the temperature’s magnitude to modulate the vorticity. Where there is higher temperature there will be more “spinning motion” applied to the simulation. |
| Velocity Vorticity | Uses the velocity’s magnitude to modulate the vorticity. Where there is higher velocity there will be more “spinning motion” applied to the simulation. |
| UVs |
Does the field system 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. |
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. |
The properties control the time at which the node is active. See Timeline for editing time segments.
| Parameter | Details |
|---|---|
| Duration |
Control the duration of the node’s time segment.
|
| Node Time | The custom start and end time for the node. |
| Duration (Timecode) | The length of the node’s time segment (in time). |
| Duration (Frames) | The length of the node’s time segment (in frames). |
| Time Segment Enabled | Set whether the node’s time segment is enabled or not in the Timeline. |
| 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 |