Determine whether the ray with the given <code>origin</code> and the given <code>dir</code> intersects the frontface of the triangle consisting of the three vertices
<code>v0</code>, <code>v1</code> and <code>v2</code> and return the value of the parameter <i>t</i> in the ray equation <i>p(t) = origin + t * dir</i> of the point of intersection.
<p>
This is an implementation of the <a href="http://www.graphics.cornell.edu/pubs/1997/MT97.pdf">
Fast, Minimum Storage Ray/Triangle Intersection</a> method.
<p>
This test implements backface culling, that is, it will return <code>false</code> when the triangle is in clockwise
winding order assuming a <i>right-handed</i> coordinate system when seen along the ray's direction, even if the ray intersects the triangle.
This is in compliance with how OpenGL handles backface culling with default frontface/backface settings.
@param origin
the ray's origin
@param dir
the ray's direction
@param v0
the position of the first vertex
@param v1
the position of the second vertex
@param v2
the position of the third vertex
@param epsilon
a small epsilon when testing rays that are almost parallel to the triangle
@return the value of the parameter <i>t</i> in the ray equation <i>p(t) = origin + t * dir</i> of the point of intersection
if the ray intersects the frontface of the triangle; <code>-1.0</code> otherwise
Determine whether the ray with the given <code>origin</code> and the given <code>dir</code> intersects the frontface of the triangle consisting of the three vertices <code>v0</code>, <code>v1</code> and <code>v2</code> and return the value of the parameter <i>t</i> in the ray equation <i>p(t) = origin + t * dir</i> of the point of intersection. <p> This is an implementation of the <a href="http://www.graphics.cornell.edu/pubs/1997/MT97.pdf"> Fast, Minimum Storage Ray/Triangle Intersection</a> method. <p> This test implements backface culling, that is, it will return <code>false</code> when the triangle is in clockwise winding order assuming a <i>right-handed</i> coordinate system when seen along the ray's direction, even if the ray intersects the triangle. This is in compliance with how OpenGL handles backface culling with default frontface/backface settings.
@see #intersectRayTriangleFront(double, double, double, double, double, double, double, double, double, double, double, double, double, double, double, double)
@param origin the ray's origin @param dir the ray's direction @param v0 the position of the first vertex @param v1 the position of the second vertex @param v2 the position of the third vertex @param epsilon a small epsilon when testing rays that are almost parallel to the triangle @return the value of the parameter <i>t</i> in the ray equation <i>p(t) = origin + t * dir</i> of the point of intersection if the ray intersects the frontface of the triangle; <code>-1.0</code> otherwise