public Vertex3D[] Build(Vector3 position, float width, float height, float depth, float ClockwiseRotationDegreesAroundY, RectangularCuboidMeshTexCoords?texCoords = null)
{
if (width <= 0.0f)
{
width = 1.0f;
}
if (height <= 0.0f)
{
height = 1.0f;
}
if (depth <= 0.0f)
{
depth = 1.0f;
}
var tex = texCoords == null?RectangularCuboidMeshTexCoords.StandardCuboidTexCoords() : texCoords.Value;
var rads = ClockwiseRotationDegreesAroundY * (float)Math.PI / 180.0f;
var twoPi = (float)Math.PI * 2.0f;
//Don't really need to clamp to range here but why not..
while (rads >= twoPi)
{
rads -= twoPi;
}
while (rads < 0.0f)
{
rads += twoPi;
}
return(GenerateMesh(ref position, ref width, ref height, ref depth, ref rads, ref tex));
}
private Vertex3D[] GenerateMesh(ref Vector3 position, ref float width, ref float height, ref float depth, ref float cwRadsAroundY, ref RectangularCuboidMeshTexCoords tex)
{
var rotationMatrix = Matrix4x4.CreateRotationY(-cwRadsAroundY);
var normals = new Vector3[]
{
new Vector3(0.0f, 0.0f, -1.0f),
new Vector3(1.0f, 0.0f, 0.0f),
new Vector3(0.0f, 0.0f, 1.0f),
new Vector3(-1.0f, 0.0f, 0.0f),
new Vector3(0.0f, 1.0f, 0.0f),
new Vector3(0.0f, -1.0f, 0.0f),
};
for (var n = 0; n < 6; n++)
{
//Extra normalise not really needed, but might clean up some fp rounding errors
normals[n] = Vector3.Normalize(Vector3.Transform(normals[n], rotationMatrix));
}
/*
* Coordinate System is RHS, with y upwards and z positive into camera
*
* The faces are set out on the cube such that
* 1 to 4: side faces, with side one facing along z (into camera) for an unrotated cube mesh (up is positive y)
* 1 = back face, normal along negative z
* 2 = right face, normal along positive x
* 3 = front face, normal along positive z
* 4 = left face, normal along negative x
* side 5 is top face. with the top of that 2d area being furthest along negative z in the above example
* side 6 is bottom face. orientated so that upon rotating the above mentioned around the x axis the
* top and bottom face would appear the same way up when facing the camera
* i.e. when unrotated the top of the 2d area will be closest to camera upside down (highest z value).
* a little tricky to describe - but should be roughly "as expected"
*/
var mesh = new Vertex3D[]
{
//Face 1
new Vertex3D
{
Position = new Vector3(1.0f, -1.0f, -1.0f),
TexCoord = tex.One.BottomLeft,
Normal = normals[0]
},
new Vertex3D
{
Position = new Vector3(1.0f, 1.0f, -1.0f),
TexCoord = tex.One.TopLeft,
Normal = normals[0]
},
new Vertex3D
{
Position = new Vector3(-1.0f, 1.0f, -1.0f),
TexCoord = tex.One.TopRight,
Normal = normals[0]
},
new Vertex3D
{
Position = new Vector3(1.0f, -1.0f, -1.0f),
TexCoord = tex.One.BottomLeft,
Normal = normals[0]
},
new Vertex3D
{
Position = new Vector3(-1.0f, 1.0f, -1.0f),
TexCoord = tex.One.TopRight,
Normal = normals[0]
},
new Vertex3D
{
Position = new Vector3(-1.0f, -1.0f, -1.0f),
TexCoord = tex.One.BottomRight,
Normal = normals[0]
},
//Face 2
new Vertex3D
{
Position = new Vector3(1.0f, -1.0f, 1.0f),
TexCoord = tex.Two.BottomLeft,
Normal = normals[1]
},
new Vertex3D
{
Position = new Vector3(1.0f, 1.0f, 1.0f),
TexCoord = tex.Two.TopLeft,
Normal = normals[1]
},
new Vertex3D
{
Position = new Vector3(1.0f, 1.0f, -1.0f),
TexCoord = tex.Two.TopRight,
Normal = normals[1]
},
new Vertex3D
{
Position = new Vector3(1.0f, -1.0f, 1.0f),
TexCoord = tex.Two.BottomLeft,
Normal = normals[1]
},
new Vertex3D
{
Position = new Vector3(1.0f, 1.0f, -1.0f),
TexCoord = tex.Two.TopRight,
Normal = normals[1]
},
new Vertex3D
{
Position = new Vector3(1.0f, -1.0f, -1.0f),
TexCoord = tex.Two.BottomRight,
Normal = normals[1]
},
//Face 3
new Vertex3D
{
Position = new Vector3(-1.0f, -1.0f, 1.0f),
TexCoord = tex.Three.BottomLeft,
Normal = normals[2]
},
new Vertex3D
{
Position = new Vector3(-1.0f, 1.0f, 1.0f),
TexCoord = tex.Three.TopLeft,
Normal = normals[2]
},
new Vertex3D
{
Position = new Vector3(1.0f, 1.0f, 1.0f),
TexCoord = tex.Three.TopRight,
Normal = normals[2]
},
new Vertex3D
{
Position = new Vector3(-1.0f, -1.0f, 1.0f),
TexCoord = tex.Three.BottomLeft,
Normal = normals[2]
},
new Vertex3D
{
Position = new Vector3(1.0f, 1.0f, 1.0f),
TexCoord = tex.Three.TopRight,
Normal = normals[2]
},
new Vertex3D
{
Position = new Vector3(1.0f, -1.0f, 1.0f),
TexCoord = tex.Three.BottomRight,
Normal = normals[2]
},
//Face 4
new Vertex3D
{
Position = new Vector3(-1.0f, -1.0f, -1.0f),
TexCoord = tex.Four.BottomLeft,
Normal = normals[3]
},
new Vertex3D
{
Position = new Vector3(-1.0f, 1.0f, -1.0f),
TexCoord = tex.Four.TopLeft,
Normal = normals[3]
},
new Vertex3D
{
Position = new Vector3(-1.0f, 1.0f, 1.0f),
TexCoord = tex.Four.TopRight,
Normal = normals[3]
},
new Vertex3D
{
Position = new Vector3(-1.0f, -1.0f, -1.0f),
TexCoord = tex.Four.BottomLeft,
Normal = normals[3]
},
new Vertex3D
{
Position = new Vector3(-1.0f, 1.0f, 1.0f),
TexCoord = tex.Four.TopRight,
Normal = normals[3]
},
new Vertex3D
{
Position = new Vector3(-1.0f, -1.0f, 1.0f),
TexCoord = tex.Four.BottomRight,
Normal = normals[3]
},
//Face 5
new Vertex3D
{
Position = new Vector3(-1.0f, 1.0f, 1.0f),
TexCoord = tex.Five.BottomLeft,
Normal = normals[4]
},
new Vertex3D
{
Position = new Vector3(-1.0f, 1.0f, -1.0f),
TexCoord = tex.Five.TopLeft,
Normal = normals[4]
},
new Vertex3D
{
Position = new Vector3(1.0f, 1.0f, -1.0f),
TexCoord = tex.Five.TopRight,
Normal = normals[4]
},
new Vertex3D
{
Position = new Vector3(-1.0f, 1.0f, 1.0f),
TexCoord = tex.Five.BottomLeft,
Normal = normals[4]
},
new Vertex3D
{
Position = new Vector3(1.0f, 1.0f, -1.0f),
TexCoord = tex.Five.TopRight,
Normal = normals[4]
},
new Vertex3D
{
Position = new Vector3(1.0f, 1.0f, 1.0f),
TexCoord = tex.Five.BottomRight,
Normal = normals[4]
},
//Face 6
new Vertex3D
{
Position = new Vector3(1.0f, -1.0f, -1.0f),
TexCoord = tex.Six.BottomLeft,
Normal = normals[5]
},
new Vertex3D
{
Position = new Vector3(1.0f, -1.0f, 1.0f),
TexCoord = tex.Six.TopLeft,
Normal = normals[5]
},
new Vertex3D
{
Position = new Vector3(-1.0f, -1.0f, 1.0f),
TexCoord = tex.Six.TopRight,
Normal = normals[5]
},
new Vertex3D
{
Position = new Vector3(1.0f, -1.0f, -1.0f),
TexCoord = tex.Six.BottomLeft,
Normal = normals[5]
},
new Vertex3D
{
Position = new Vector3(-1.0f, -1.0f, 1.0f),
TexCoord = tex.Six.TopRight,
Normal = normals[5]
},
new Vertex3D
{
Position = new Vector3(-1.0f, -1.0f, -1.0f),
TexCoord = tex.Six.BottomRight,
Normal = normals[5]
},
};
var numVerts = mesh.Length;
var hw = 0.5f * width;
var hh = 0.5f * height;
var hd = 0.5f * depth;
for (var n = 0; n < numVerts; n++)
{
var pos = mesh[n].Position;
mesh[n].Position = Vector3.Transform(new Vector3(hw * pos.X, hh * pos.Y, hd * pos.Z), rotationMatrix) + position;
}
return(mesh);
}
