Is there a way to calculate this transformation?

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Discussion Overview

The discussion revolves around calculating the distance traveled by a ball from a transformed perspective, specifically when viewed from a point on the ground rather than from a top-down view. The focus includes mathematical modeling, particularly using cylindrical coordinates, and the implications of perspective on distance measurement.

Discussion Character

  • Exploratory
  • Mathematical reasoning

Main Points Raised

  • One participant suggests using cylindrical coordinates (r,θ) to analyze the second perspective, noting that while θ is easily determined, r poses more difficulty.
  • Another participant proposes that if the eye-point is at the center of the polar coordinates, the angle θ is known, but the distance r to the ball must still be calculated, potentially using trigonometry under the assumption of a flat earth.
  • There is mention of needing to know the distance to the tree-line, which introduces additional complexity to the calculations based on direction.
  • Some participants express uncertainty about the specific techniques or methods being sought for measuring the distance in this transformed view.

Areas of Agreement / Disagreement

Participants express varying approaches to the problem, with no consensus on the best method for calculating the distance. Multiple competing views and uncertainties remain regarding the techniques and assumptions involved.

Contextual Notes

The discussion highlights limitations related to assumptions about the environment (e.g., flat earth) and the need for specific measurements (e.g., distance to tree-line) that may affect the calculations.

wirefree
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Namaste & G'day!

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.
 
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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
 

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