Jump to content
  • Advertisement
Sign in to follow this  
ericsson20070720

zero or one or .... parameters

This topic is 3939 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.

If you intended to correct an error in the post then please contact us.

Recommended Posts

Hi I am reading a book about geometry and computer graphics . It says that : " The common theme that unifies the analysis of the queries is that the objects can be parametrized by zero ( point ) , one ( segment ) ,two ( triangle , rectangle ) , or three ( tetradedra , box ) parameters. " I can't understand what is zero or one or two or three parameter . Please tell me that what it means . thanks

Share this post


Link to post
Share on other sites
Advertisement
Precise answer: the number of parameters for those objects is the smallest dimensionality n such that the object can be bijectively and continuously mapped to a subset of Rn.

Hand-waving answer: parameters are used to represent movement inside the object.
You can't move inside a point (because there's nowhere to go except stay on the point), therefore there are no movement parameters. When on a segment, you can move from one end to the other, and so you can represent your position by a single parameter (for instance, the distance from one of the segment edges). When on a triangle, rectangle or other surface, you can move both in the north-south direction and the east-west direction (or any combination of the two), and you cannot represent both movements with a single parameter—but two parameters (latitude, longitude) are enough to represent any position on a surface. Finally, when inside a volume, using only two parameters will let you position yourself in a horizontal plane, but you would still need to specify the altitude of that plane, and so you need three parameters (left-right, forward-backward, up-down).

Share this post


Link to post
Share on other sites
Sign in to follow this  

  • Advertisement
×

Important Information

By using GameDev.net, you agree to our community Guidelines, Terms of Use, and Privacy Policy.

We are the game development community.

Whether you are an indie, hobbyist, AAA developer, or just trying to learn, GameDev.net is the place for you to learn, share, and connect with the games industry. Learn more About Us or sign up!

Sign me up!