Help me understanding vectors.

Erik23a86 · 2004-01-08T08:29:30

Can anyone show me what the vectors of a triangle are with the co-ordinates (-3,-2), (-2,2), (-1,-1)? I just not know how the vectors a running and in wich direction they are pointing. I know how to calculate the vectors: Vector.x = Point1.x - Point2.x; Vector.y = Point1.y - Point2.y; If I do this I get a co-ordinate, but I don''t understand how this could be the correct vector. Please show me how it must be done (examples). Thanks. The One.

For Beginners

Started by Erik23a86 January 06, 2004 10:58 AM

15 comments, last by Erik23a86 20 years, 3 months ago

Erik23a86

122

Author

January 06, 2004 04:23 PM

A vector has a x,y,z value. But what does the x represent and what does the y represent and what does the z represent?

Thanks.

The One.

Anonymous

January 06, 2004 05:30 PM

quote:Original post by Erik23a86
A vector has a x,y,z value. But what does the x represent and what does the y represent and what does the z represent?

Thanks.

The One.

The vector V then is assumned to be the vector with it''s tail at (0,0,0) and it''s head at (x,y,z).

Anonymous

January 06, 2004 05:53 PM

Try reading some of this:

http://mathforum.org/~klotz/Vectors/vectors.html

In your case for a triangle:

an example is three VERTEX''s?(sp?) with vertices

[0,0,0], [5,10,0], [10,0,0]

Erik23a86

122

Author

January 07, 2004 08:25 AM

How can (for example) that a triangle has a vector? What does the vector say about the triangle (or the points)? And why can the normal and collision be calculated with vectors?

Thanks.

The One.

Fidelio66

164

January 07, 2004 10:37 AM

A triangle has 3 corner points.
A vector is a direction. This is usually expressed as a point, and the direction is then along the line through the origin (0,0) or (0,0,0) and the point.
In 3D programming this is often thrown together and everything is called a vertex, used for both points and directions. If you are confused about which vertors a triangle has then maybe you are confusing the two.

Erik23a86

122

Author

January 07, 2004 11:12 AM

So if I understand it correctly, the vector between the points (1,-1) and (-2,3) is a vector with a origin of (0,0) and an end of <-3,4>. Like in the picture.