Calculate the area intersected by a sphere and a rectangular prism

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Homework Help Overview

The discussion revolves around calculating the area of intersection between a sphere and a rectangular prism. The original poster is exploring the complexities involved in determining the intersecting area, particularly noting that the resulting polygon on the sphere may not consist of geodesics and that parts of the prism may embed within the sphere, leading to irregular shapes.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Participants are considering how to compute the intersecting areas of the prism and sphere, with an emphasis on the total area being close to ##4 \pi r^2##. There are inquiries about the format of the figures involved and whether equations are available. Some participants are questioning the accuracy of existing methods and the relevance of computational cost in the context of interface reconstruction.

Discussion Status

The discussion is ongoing, with participants sharing ideas and raising questions about the nature of the intersection and the methods for calculating the area. There is acknowledgment of the challenges posed by the irregular shapes formed during the intersection, and some guidance is being sought regarding existing literature on the topic.

Contextual Notes

There is a mention of the lack of literature specifically addressing this problem, which may indicate a gap in available resources. Additionally, the discussion touches on the balance between accuracy and computational efficiency in the context of interface reconstruction.

guv
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Homework Statement
I am trying to figure out the area on the surface of a sphere as a result of the sphere intersecting a much smaller rectangular prism.
Relevant Equations
N/A
Think of a 3D rectilinear grid made of these rectangular cells, some of the cells will intersect with the sphere. I am trying to compute each intersecting area and the total sum. Ideally the total sum of the intersecting area should be close to ##4 \pi r^2##. I have not found any literature discussing this problem. Part of the problem is that the polygon on the sphere as a result of the intersection is not necessarily made of geodesics. Moreover, part of the rectangular prism can embed inside the sphere causing irregular intersecting shape. I am looking for ideas how to get this done correctly. Has anyone seen any problem. I would imagine this might be useful in computer science, but obviously people there are not too concerned with accuracy of the result. Thanks!
 
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guv said:
Homework Statement: I am trying to figure out the area on the surface of a sphere as a result of the sphere intersecting a much smaller rectangular prism.
Relevant Equations: N/A

Think of a 3D rectilinear grid made of these rectangular cells, some of the cells will intersect with the sphere. I am trying to compute each intersecting area and the total sum. Ideally the total sum of the intersecting area should be close to ##4 \pi r^2##. I have not found any literature discussing this problem. Part of the problem is that the polygon on the sphere as a result of the intersection is not necessarily made of geodesics. Moreover, part of the rectangular prism can embed inside the sphere causing irregular intersecting shape. I am looking for ideas how to get this done correctly. Has anyone seen any problem. I would imagine this might be useful in computer science, but obviously people there are not too concerned with accuracy of the result. Thanks!
If the polyhedron is inside the sphere the only possible points of intersections will be at points or edges on the polyhedron where two or more polygons meet. At least that's what I come up with based on your description.
 
How are these figures given? Do you have their equations, or are they given in a different format?
 
guv said:
Has anyone seen any problem. I would imagine this might be useful in computer science, but obviously people there are not too concerned with accuracy of the result.
They call it interface reconstruction and are very concerned with accuracy vs. computational cost.
 
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Take a look at the pictures attached, I am guessing 'interface construction' is the algorithm that results in what we see in the pictures. How about area calculation? Is there any literature on how to find the intersection and area in the general case? The intersection looks like a simpler problem, the area seems difficult.
 

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