Neural Network Fluid Simulation Bypassing Navier-Stokes

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Solution Overview

Problem

Conventional fluid simulation techniques require significant computational resources and time to achieve high-resolution simulations, making real-time high-resolution fluid simulations impractical due to the computational bottleneck associated with the time step size needed for stability.

Innovation Solution

The approach generates a density tensor and rigid body map tensor for a large number of particles within a sub-domain, using these tensors as input channels for a neural network to predict updated positions and velocities without solving the Navier-Stokes equations, enabling efficient high-resolution fluid simulations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional fluid simulation techniques are used to achieve high-resolution simulations, then simulation accuracy is improved, but computational time and resource requirements increase significantly

Engineering Contradiction:
Improvesimulation accuracyVSAvoidcomputational time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent pre-computes and stores fluid simulation data in lookup tables during an offline training phase. During real-time simulation, the pre-trained neural network rapidly retrieves and interpolates results from these tables, eliminating the need for computationally intensive Navier-Stokes calculations at runtime. This preliminary preparation enables high-resolution fluid simulation to be achieved in real-time without sacrificing accuracy.

Inventive Principle:
Principle #10Preliminary action

2Stability of the object's composition

If traditional fluid simulation techniques are used with small time step sizes for stability, then simulation stability is improved, but simulation speed decreases

Engineering Contradiction:
Improvesimulation stabilityVSAvoidsimulation speed
Core Design Contradiction:
Stability of the object's compositionVSProductivity

Solution Approach 1:

The patent replaces the traditional mechanical numerical integration approach (which requires small time steps for stability) with a neural network-based system. The neural network learns the stable integration behavior during training and can predict fluid evolution over larger time intervals without requiring small time step sizes, thereby maintaining stability while improving simulation speed.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Quantity of substance

If traditional techniques are used to simulate a large number of water particles, then simulation detail is improved, but computational resources required increase

Engineering Contradiction:
Improvenumber of particlesVSAvoidcomputational resources
Core Design Contradiction:
Quantity of substanceVSUse of energy by moving object

Solution Approach 1:

The patent segments the fluid simulation domain into multiple sub-domains or spatial regions. The neural network processes each sub-domain independently using localized lookup tables, allowing the system to handle a large total number of particles across the entire scene while keeping computational resources required for each individual sub-domain manageable and efficient.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentUS11954791B2Fluid simulations using one or more neural networks
Publication Date: 2024.04.09 NVIDIA CORP
  • US11954791B2 patent drawing
  • US11954791B2 patent drawing
  • US11954791B2 patent drawing

AI summary

Approaches in accordance with various embodiments provide for fluid simulation with substantially reduced time and memory requirements with respect to conventional approaches. In particular, various embodiments can perform time and energy efficient, large scale fluid simulation on processing hardware using a method that does not solve for the Navier-Stokes equations to enforce incompressibility. Instead, various embodiments generate a density tensor and rigid body map tensor for a large number of particles contained in a sub-domain. Collectively, the density tensor and rigid body map may represent input channels of a network with three spatial-dimensions. The network may apply a series of operations to the input channels to predict an updated position and updated velocity for each particle at the end of a frame. Such approaches can handle tens of millions of particles within a virtually unbounded simulation domain, as compared to classical approaches that solve for the Navier-Stokes equations.