Method to generate displacement for symmetry mesh

A method of encoding a mesh, the method comprising:

• generating a bitstream comprising the mesh,
• wherein a symmetry plane that divides the mesh into a first side and a second side opposite the first side is determined,
• wherein a first plane is determined based on a first input vertex located on the first side of the mesh, a direction vector, and a first vector selected along an axis having a largest angle from the direction vector,
• wherein, as a first set, each vertex of the mesh on the second side of the mesh that is on a first side of the first plane or on the first plane is determined,
• wherein, as a second set, each vertex on the second side of the mesh that is on a second side of the first plane, the second side of the first plane opposite to the first side of the first plane is determined,
• wherein a second plane is determined based on a second input vertex on the symmetry plane, the direction vector, and a second vector that is perpendicular to the first vector and the direction vector,
• wherein, as third set, each vertex on the second side of the mesh that is on a first side of the second plane or on the second plane is determined,
• wherein, as a fourth set, each vertex on the second side of the mesh that is on a second side of the second plane, the second side of the second plane opposite to the first side of the first plane is determined,
• wherein a vertex to be mapped to the first input vertex on the first side of the mesh is determined based on (i) a line that passes through the first input vertex and the second input vertex and (ii) the determined first set, the determined second set, the determined third set, and the determined fourth set, and
• wherein the vertex to be mapped to the first input vertex is further determined based on determining each intersection face defined by a plurality of vertices on the second side of the mesh that intersects with at least one vertex from the first set, the second set, the third set, and the fourth set, in which based on a determination that the line passes through a first set of N intersection points on the first side of the mesh and a second set of M intersection points on the second side of the mesh, the intersection points from the first set are mapped to a corresponding intersection point in the second set in a decreasing order of distance from the symmetry plane until the first set or the second set includes one or more unmapped intersection points, the one or more unmapped intersection points are mapped to a corresponding vertex on an opposite side of the mesh, and in which N is not equal to M and both N and M are integers greater than or equal to 2.

A method of decoding a mesh, the method comprising:

• processing a bitstream comprising the mesh,
• wherein a symmetry plane that divides the mesh into a first side and a second side opposite the first side is determined,
• wherein a first plane is determined based on a first input vertex located on the first side of the mesh, a direction vector, and a first vector selected along an axis having a largest angle from the direction vector,
• wherein, as a first set, each vertex of the mesh on the second side of the mesh that is on a first side of the first plane or on the first plane is determined,
• wherein, as a second set, each vertex on the second side of the mesh that is on a second side of the first plane, the second side of the first plane opposite to the first side of the first plane is determined,
• wherein a second plane is determined based on a second input vertex on the symmetry plane, the direction vector, and a second vector that is perpendicular to the first vector and the direction vector,
• wherein, as third set, each vertex on the second side of the mesh that is on a first side of the second plane or on the second plane is determined,
• wherein, as a fourth set, each vertex on the second side of the mesh that is on a second side of the second plane, the second side of the second plane opposite to the first side of the first plane is determined,
• wherein a vertex to be mapped to the first input vertex on the first side of the mesh is determined based on (i) a line that passes through the first input vertex and the second input vertex and (ii) the determined first set, the determined second set, the determined third set, and the determined fourth set, and
• wherein the vertex to be mapped to the first input vertex is further determined based on determining each intersection face defined by a plurality of vertices on the second side of the mesh that intersects with at least one vertex from the first set, the second set, the third set, and the fourth set, in which based on a determination that the line passes through a first set of N intersection points on the first side of the mesh and a second set of M intersection points on the second side of the mesh, the intersection points from the first set are mapped to a corresponding intersection point in the second set in a decreasing order of distance from the symmetry plane until the first set or the second set includes one or more unmapped intersection points, the one or more unmapped intersection points are mapped to a corresponding vertex on an opposite side of the mesh, and in which N is not equal to M and both N and M are integers greater than or equal to 2.