Undergrad Is there a way to calculate this transformation?

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Calculating the distance traveled by a ball from a transformed perspective, such as a cylindrical coordinate system, involves determining the angle (θ) and the radial distance (r) from the observer's viewpoint. While θ can be easily identified, calculating r is more complex and may require knowledge of the ball's diameter and the distance to nearby landmarks like the tree-line. Trigonometry can be applied to find r, assuming a flat surface. The perspective view complicates measurements, as it distorts the dimensions of the polo field. Accurate calculations depend on the observer's position and the direction of the ball.
wirefree
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Imagine a helicopter view of a Polo ground. It's length & breadth are known.

Screenshot_20240316-165049.png



Now you are seated where the blue dot is. Your view is such:

IMG_2024-03-16-16-48-17-200~2.jpg


How do mathematicians calculate the distance travelled by a ball from the second perspective?

From the top view, this would be trivial.

But now your view is transformed.
 
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I think of the second prespective in cylindrical coordinates (r,θ). θ is “easy” to determine, r is more difficult. In a perfect world, one could measure the diameter of the ball to determine its distance. There are other experimental techniques, but I am unsure exactly what you are looking for.
 
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Suppose the eye-point location is at the center of the polar coordinates (##r_{eye}=0##) and the angle, ##\theta##, of the polar coordinates of the ball are known. The distance to the ball location, ##r##, remains to be determined. Assuming a flat earth, ##r## can be calculated using trigonometry. You would need to know the distance to the tree-line. That tree-line has sides and its distance would require some calculations that depend on the direction.
 
Frabjous said:
I think of the second prespective in cylindrical coordinates (r,θ). θ is “easy” to determine, r is more difficult. In a perfect world, one could measure the diameter of the ball to determine its distance. There are other experimental techniques, but I am unsure exactly what you are looking for.
Here's a view:

Untitled1.png



You see how the perspective view squashes the 160yd width of the polo field.
 
FactChecker said:
Suppose the eye-point location is at the center of the polar coordinates (##r_{eye}=0##) and the angle, ##\theta##, of the polar coordinates of the ball are known. The distance to the ball location, ##r##, remains to be determined. Assuming a flat earth, ##r## can be calculated using trigonometry. You would need to know the distance to the tree-line. That tree-line has sides and its distance would require some calculations that depend on the direction.

I am interested in following your suggestion. Please annotate as briefly as convenient, Sir.
Untitled2.png
 
Here is a little puzzle from the book 100 Geometric Games by Pierre Berloquin. The side of a small square is one meter long and the side of a larger square one and a half meters long. One vertex of the large square is at the center of the small square. The side of the large square cuts two sides of the small square into one- third parts and two-thirds parts. What is the area where the squares overlap?

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