Added initial Smoothed Particle Hydrodynamics implementation (SPH), for CPU and CUDA.

This software is contributed under the ZLib license by Rama Hoetzlein, http://www.rchoetzlein.com
We plan to integrate the SPH into the core Bullet library, including interaction with rigid bodies and soft bodies.

Extras/sph/common/particle.h

@@ -0,0 +1,29 @@
+/*
+  FLUIDS v.1 - SPH Fluid Simulator for CPU and GPU
+  Copyright (C) 2009. Rama Hoetzlein, http://www.rchoetzlein.com
+
+  ZLib license
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the authors be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+*/
+#ifndef DEF_PARTICLE
+	#define DEF_PARTICLE
+	
+	#include "vector.h"
+
+
+
+#endif