1. A viewing device comprising:
an eyepiece; and
a reference plate that is provided with a first clear plate including a reticle forming surface on which a reticle is formed, said reference plate being positioned on an optical axis of said eyepiece;
wherein said reticle forming surface is curved in accordance with a field curvature of said eyepiece.
2. A viewing device according to claim 1, wherein said reticle forming surface is curved so as to approximately accord with a field curvature of a sagittal image surface of said eyepiece.
3. A viewing device according to claim 1, wherein said reference plate is provided with a frame forming surface on which a frame for a field of view is formed.
4. A viewing device according to claim 1, wherein said reference plate is composed of two clear plates including said first clear plate, and said two plates are bonded in such a manner that said reticle forming surface is a bonded surface.
5. A viewing device according to claim 1, wherein said reference plate has no significant refracting power.
6. A viewing device according to claim 4, wherein, on said reference plate, both an incidence surface and an exit surface are plane.
7. A viewing device according to claim 1, wherein said reference plate includes a second clear plate that is provided with a frame forming surface on which a frame for a field of view is formed, said reticle forming surface and said frame forming surface are placed so as to face each other, and the radius of curvature of said reticle forming surface and the radius of curvature of said frame forming surface are different.
8. A viewing device according to claim 7, wherein said frame forming surface is curved so as to approximately accord with a field curvature of a meridional image surface of said eyepiece.
9. A viewing device according to claim 7, further comprising a sealing member that hermetically seals a gap which is formed between the peripheral portions of said first and second clear plates.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
What is claimed is:
1. A computer-based system for smoothing a mesh model of a three-dimensional object or surface, the mesh model having a set of connected faces, each face being a geometric shape with a predetermined number of vertices and a corresponding number of edges, each edge connecting two of the predetermined number of vertices, each vertex being a data point describing the object or surface, the computer, including a processor coupled to a memory, the system comprising:
a subdivision element to check a first edge against a predetermined subdivision criteria;
an insertion element to insert a new subdivision point along the first edge, when the first edge does not meet the predetermined subdivision criteria; and
an extrusion element to extrude the new subdivision point so that it lies on a curve, wherein the curve passes through the vertices connected by the first edge orthogonal to normal vectors at the vertices.
2. A method for refining a mesh model of a three-dimensional object or shape, the mesh model including a plurality of first geometric shapes, comprising the steps of:
selecting at least one of the first geometric shapes;
recursively subdividing each of the selected first geometric shapes into a plurality of second geometric shapes; and
displaying each of the plurality of second geometric shapes.
3. A method for refining a mesh model of a three-dimensional object or shape, the mesh model including a plurality of first geometric shapes having edges, comprising the steps of:
selecting at least one of the first geometric shapes;
for each one of the edges of the selected geometric shapes:
i) determining if the one of the edges meets a predetermined subdivision criteria; and
ii) if the one of the edges meets the predetermined criteria, subdividing the one of the edges; and
subdividing each of the selected first geometric shapes into a plurality of second geometric shapes as a function of the subdivided edges.