Feng Qiu, Ye Zhao, Zhe Fan, Xiaomin Wei, Haik Lorenz, Jianning Wang, Suzanne Yoakum-Stover, Arie Kaufman, Klaus Mueller

Center for Visual Computing and Department of Computer Science, Stony Brook University

GPU Accelerated Dispersion Simulation for Urban Security

OverviewOverview• Simulating and visualizing the propagation of dispersive Simulating and visualizing the propagation of dispersive

contaminantscontaminants

• Open environments characterized by sky-scrapers and deep Open environments characterized by sky-scrapers and deep urban canyonsurban canyons

• Multiple Relaxation Time Lattice Boltzmann Model for flow Multiple Relaxation Time Lattice Boltzmann Model for flow simulationsimulation

• GPU accelerated computation and visualizationGPU accelerated computation and visualization

OverviewOverview• Simulating and visualizing the propagation of dispersive Simulating and visualizing the propagation of dispersive

contaminantscontaminants

• Open environments characterized by sky-scrapers and deep Open environments characterized by sky-scrapers and deep urban canyonsurban canyons

• Multiple Relaxation Time Lattice Boltzmann Model for flow Multiple Relaxation Time Lattice Boltzmann Model for flow simulationsimulation

• GPU accelerated computation and visualizationGPU accelerated computation and visualization

GPU AccelerationGPU Acceleration• Local operations in LBM are accelerated by GPULocal operations in LBM are accelerated by GPU

• Data layout:Data layout:

• One state variable stored in one volumeOne state variable stored in one volume

• Each volume packed into a series of 2D texturesEach volume packed into a series of 2D textures

• Boundary link information packed into small 2D texturesBoundary link information packed into small 2D textures

• Computation:Computation:

• LBM operations mapped to fragment programLBM operations mapped to fragment program

• Results stored in pixel buffers and copied back to textures Results stored in pixel buffers and copied back to textures for next stepfor next step

• Simulation and visualization on same GPU, reducing data Simulation and visualization on same GPU, reducing data transfertransfer

GPU AccelerationGPU Acceleration• Local operations in LBM are accelerated by GPULocal operations in LBM are accelerated by GPU

• Data layout:Data layout:

• One state variable stored in one volumeOne state variable stored in one volume

• Each volume packed into a series of 2D texturesEach volume packed into a series of 2D textures

• Boundary link information packed into small 2D texturesBoundary link information packed into small 2D textures

• Computation:Computation:

• LBM operations mapped to fragment programLBM operations mapped to fragment program

• Results stored in pixel buffers and copied back to textures Results stored in pixel buffers and copied back to textures for next stepfor next step

• Simulation and visualization on same GPU, reducing data Simulation and visualization on same GPU, reducing data transfertransfer

VisualizationVisualization• Rendering of building:Rendering of building:

• Building textures from real imagesBuilding textures from real images

• Reserve texture memory for LBM simulationReserve texture memory for LBM simulation

• Shader program adds weathering and cracks to texturesShader program adds weathering and cracks to textures

• Rendering of smoke:Rendering of smoke:

• Splatting of smoke particlesSplatting of smoke particles

• Splats distorted for correct projectionSplats distorted for correct projection

• Half angle slicing for self-shadowingHalf angle slicing for self-shadowing

VisualizationVisualization• Rendering of building:Rendering of building:

• Building textures from real imagesBuilding textures from real images

• Reserve texture memory for LBM simulationReserve texture memory for LBM simulation

• Shader program adds weathering and cracks to texturesShader program adds weathering and cracks to textures

• Rendering of smoke:Rendering of smoke:

• Splatting of smoke particlesSplatting of smoke particles

• Splats distorted for correct projectionSplats distorted for correct projection

• Half angle slicing for self-shadowingHalf angle slicing for self-shadowingLattice Boltzmann Model (LBM)Lattice Boltzmann Model (LBM)• LBM models Boltzmann particle dynamics on a regular latticeLBM models Boltzmann particle dynamics on a regular lattice

• Streaming and collision in discrete time stepsStreaming and collision in discrete time steps

• 22ndnd order space-time accurate CFD method order space-time accurate CFD method

• Advantages: GPU accelerated, complex boundary, easy to Advantages: GPU accelerated, complex boundary, easy to implement, multi-resolution, sensor feedbackimplement, multi-resolution, sensor feedback

Lattice Boltzmann Model (LBM)Lattice Boltzmann Model (LBM)• LBM models Boltzmann particle dynamics on a regular latticeLBM models Boltzmann particle dynamics on a regular lattice

• Streaming and collision in discrete time stepsStreaming and collision in discrete time steps

• 22ndnd order space-time accurate CFD method order space-time accurate CFD method

• Advantages: GPU accelerated, complex boundary, easy to Advantages: GPU accelerated, complex boundary, easy to implement, multi-resolution, sensor feedbackimplement, multi-resolution, sensor feedback

Smoke in city modelSmoke in city modelSmoke in city modelSmoke in city model

Original façadeOriginal façadeOriginal façadeOriginal façade Façade variationFaçade variationFaçade variationFaçade variation

Sensor FeedbackSensor Feedback• Two methods:Two methods:

• Incorporate sensor data as body forceIncorporate sensor data as body force

• Modify boundary nodes affecting sensor readingsModify boundary nodes affecting sensor readings

Sensor FeedbackSensor Feedback• Two methods:Two methods:

• Incorporate sensor data as body forceIncorporate sensor data as body force

• Modify boundary nodes affecting sensor readingsModify boundary nodes affecting sensor readings

Snapshots of simulation with smoke and flow streamlinesSnapshots of simulation with smoke and flow streamlinesSnapshots of simulation with smoke and flow streamlinesSnapshots of simulation with smoke and flow streamlines

Streamlines in Time SquareStreamlines in Time SquareStreamlines in Time SquareStreamlines in Time Square

Single GPU ResultsSingle GPU Results• West Village area of New York City (10 blocks)West Village area of New York City (10 blocks)

• Lattice size: 90x30x60 with grid unit 3.8mLattice size: 90x30x60 with grid unit 3.8m

• Speedup (GPU/CPU): 7Speedup (GPU/CPU): 7

Single GPU ResultsSingle GPU Results• West Village area of New York City (10 blocks)West Village area of New York City (10 blocks)

• Lattice size: 90x30x60 with grid unit 3.8mLattice size: 90x30x60 with grid unit 3.8m

• Speedup (GPU/CPU): 7Speedup (GPU/CPU): 7

Multi-GPU ResultsMulti-GPU Results• Time Square area of New York City (110 blocks)Time Square area of New York City (110 blocks)

• Lattice size: 320x80x320 with grid unit 4.5mLattice size: 320x80x320 with grid unit 4.5m

• Speedup on 30 nodes (GPU cluster/CPU cluster): 4-5Speedup on 30 nodes (GPU cluster/CPU cluster): 4-5

Multi-GPU ResultsMulti-GPU Results• Time Square area of New York City (110 blocks)Time Square area of New York City (110 blocks)

• Lattice size: 320x80x320 with grid unit 4.5mLattice size: 320x80x320 with grid unit 4.5m

• Speedup on 30 nodes (GPU cluster/CPU cluster): 4-5Speedup on 30 nodes (GPU cluster/CPU cluster): 4-5

AcknowledgementAcknowledgement

• NSF CCR-0306438NSF CCR-0306438

• Department of Department of Homeland Security, Homeland Security, Environment Environment Measurement Measurement LaboratoryLaboratory

AcknowledgementAcknowledgement

• NSF CCR-0306438NSF CCR-0306438

• Department of Department of Homeland Security, Homeland Security, Environment Environment Measurement Measurement LaboratoryLaboratory

http://www.cs.sunysb.edu/~vislab/projects/urbansecurity