oTakhi Platform Preview: Navier-Stokes Simulator using Volume Slice Rendering

[mfdesigner]

We are making steady progress in implementing a general Navier-Stokes Fluid simulator using Volume Slice Rendering of data texture buffers.

To show a preview, here are the images of sliced volume displayed in a 2D texture for velocity, pressure, density, and divergence after 2 min of simulation.

(1) Velocity

(2) Pressure

 

(3) Density

 

(4) Divergence

 

We are working on a raycast renderer which will create the final result in a 3D volume in space.

 

 

[mfdesigner]

For those in the know, this simulator accounts for:

(1) Advection,

(2) Viscous Diffusion,

(3) External Force,

(4) Boundary Conditions,

(5) Vorticity Confinement

All is done on the GPU.

The actual performance varies depending on which GPU.

[mfdesigner]

And we have fire...

Here is a video showing Navier-Stokes simulation of smoke and fire.  This is a time progression of density within volume slices.

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Rendering of Navier-Stokes simulation requires too many dependent texture reads that stall rendering pipeline in WebGL 1.0 (OpenGL ES 2.0), which is not an issue for WebGL 2.0 (OpenGL 3.0). We are getting at best 5 fps when rendering these volume slices into 3D scene.  Until WebGL 2.0 arrives, the simulation can be visualized using sprites.

 

 

 

[mfdesigner]

One way to solve the dependent-texture-reads bottleneck in WebGL 1.0 is to use Angle_instanced_arrays extension.

Not sure if gl_InstanceId (among many other features of instancing) is supported, but if it is, a significant speed up can be obtained by

rendering each slice as separated geometry.