public FVec4 UnProject(FMat4 viewProjInverse, Fix64 viewX, Fix64 viewY, Fix64 viewWidth, Fix64 viewHeight)
{
FVec4 result = this;
result.x = (result.x - viewX) / viewWidth;
result.y = (result.y - viewY) / viewHeight;
result = result * Fix64.Two - Fix64.One;
result = result.Transform(viewProjInverse);
Fix64 wDelta = Fix64.One / result.w;
result.x *= wDelta;
result.y *= wDelta;
result.z *= wDelta;
return(result);
}
