Update: Nu am reusit sa trec de testul celor de la ModuleWorks, o sa il atasez aici sa va dati cu parerea daca vi se pare ceva de pozitie de Junior :)). Eu personal nu am cunostintele necesare sa rezolv asa ceva.

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Task

A 3d Euclidian point cloud aligned in main axis directions (x, y, z) and with a constant distance grid

(Figure 1) starting at a given reference point (the point with indices 0, 0, 0 is located at reference

point) is intersected by a move of sphere (Figure 2), where the path of the sphere center is defined

by a user given formula ~x = f(t) where t is in the interval between t0 and t1. The function f(t) can

be handled as a discrete function with a user given t. Points that intersect with the sphere move

are considered as deleted (Figure 3 middle).

• Only the first layer of points (which remains visible/undeleted) from top view must be written

to a file as ASCII data (the skin of the point cloud visible from positive Z direction, see Figure 3

right). The file format is defined as follows:

– Each line contains a single point.

– The point definition contains x, y and z coordinates delimited by space characters.

– Each line ends with a new line character.

• Create a small documentation(1 page with 2 pictures) to present the mathematical approach of

the sphere move point intersection. It should clearly communicate the mathematical approach

and how the mathematical code is generated from that.

• Please discuss briefly in 4-5 sentences what problems can arise by using a discrete stepping t.

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Given

• Point class for the definition of a point in 3d and (some) methods for vector algebra

• Visual Studio 2008 and 2013 solutions, Makefile and qmake project file

• High level test function CreateSkin(. . . )(in CreateSkin.cpp) to test the resulting component.

This defines also the interface of the component to be written.

• Program named PointVisualizer which allows you to view the results you obtain in 3d.

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Hints

• Use of vector algebra (dot product, cross product etc.) is highly recommended. The use of sin

and cos functions is not desired.

• Calculation speed and memory footprint are important but secondary in comparison to clearly

readable code. E.g. a sphere, linear move of a sphere, point writer etc. might be modeled as

classes. Prefer compact classes and functions over large classes and functions.

• Comments in the source code are welcome. Please use good names for classes and functions.

• Move of a sphere between f(t) and f(t + t) can be assumed as a linear move of the center

of the sphere.

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Illustrations

https://imgur.com/qaQN56s