How to detect if a point is inside a 3d cone

Question

1.00/5 (1 vote)

See more:

collisions

I have to write down a program that takes a point in 3d as input and tells if the point is inside a 3d cone ?

Posted 21-Sep-14 19:32pm

Member 8753410

Add a Solution

Comments

Sergey Alexandrovich Kryukov 22-Sep-14 2:41am

Please, where is your problem, in middle school mathematics? Just a hint: this is a simple 2D problem.
—SA

1 solution

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Sergey Alexandrovich Kryukov · Answer 1 · 2014-09-21T20:56:00

Some more of a hint:

This is a simple 2D problem. I assume this is a cone based on a circle. Dissect the cone with the plane passing through its axis. Consider the problem in this plane. You will get two symmetric rectangles formed by this axis and intersection with the cone surface, with the common vertex. Drop perpendicular from the point in question to the axis:

  /|
 / |   *?
/__|___|
\  |
 \ |
  \|

The location of the point relative to the cone will be determined by the angle between the axis and the straight like connecting the vertex with this point; and the angle is defined by two catheti you can easily find out. Don't forget to consider "pathological" cases when cotangents can give you NaN, or atan2, if your library has it.

—SA