Hello, I've tried to find some tutorial about matrixes on the web but...

Found only horrible hard to understand pages.

Does anobody knows a good web tutorial for people like me (so, dummies) ?

Thank you

Hello, I've tried to find some tutorial about matrixes on the web but...

Found only horrible hard to understand pages.

Does anobody knows a good web tutorial for people like me (so, dummies) ?

Thank you

> Hello, I've tried to find some tutorial about matrixes on the web but...

> Found only horrible hard to understand pages.

> Does anobody knows a good web tutorial for people like me (so, dummies) ?

zin

--

http://www.zintel.com

I'm currently writing a series of tutorials on beginning 3D Programming for

a demoscene site and I have recently posted the first part which deals with

that, the mathematics part, vectors and matrices mainly. I tried to do it in

a way that can be easily understood with diagrams and even small animations,

I would be glad if it is of any help, you may check it out at

http://www.demoscene.gr/articles/3dcoding_nuclear/3dcoding_nuc_intro....

Any feedback appreciated...

-- Nuclear / the Lab --

Quote:> Hello, I've tried to find some tutorial about matrixes on the web but...

> Found only horrible hard to understand pages.

> Does anobody knows a good web tutorial for people like me (so, dummies) ?

> Thank you

As often my best reply is : thank you ! Because I'm very happy anytime IQuote:> I'm currently writing a series of tutorials on beginning 3D

> Programming for a demoscene site and I have recently posted the first

> part which deals with that, the mathematics part, vectors and matrices

> mainly. I tried to do it in a way that can be easily understood with

> diagrams and even small animations, I would be glad if it is of any

> help, you may check it out at

> http://www.demoscene.gr/articles/3dcoding_nuclear/3dcoding_nuc_intro.ht

> ml

> Any feedback appreciated...

> -- Nuclear / the Lab --

see pages like this one that provide KNOWLEDGE to people (like me).

I've printed the page and will study it carrefully because it's exactly

what I need.

So, now the feedback : if your intention is to talk to dummies (I talk

about math dummies, with programming skills) you should show the result of

the operations you describe.

For example, "The Dot Product of 2 vectors". Would be cool to have an

example, in fact a real world example. I feel that often math are hard to

understand due to the lack of "real world example".

You know, "what the hell is this operation usefull for ??"

But, keep on writing (maybe about quaternions ??) ;-)

Thanks again

May I ask you a question ?

In my newbie's mind, I think that :

- How a vector can be a vector as with only 3 coordinates I only get a

point. As a vector is a "direction" I need 3 others coordinates, no ?

Do we presume that the start of the vector is 0,0,0 (the origin ??).

For example, when you write the len of a vector is "len = sqrt(x*x + y*y +

z*z))"... Should I read len = sqrt(x1*x2 + y1*y2 + z1*z2)) when x1,y1,z1

are the "start" of the the vector and x2,y2,z2 the "end" ???

Ahem... Don't want to abuse but some another help would be greatly

appreciated ;-)

Thanks again

> May I ask you a question ?

> In my newbie's mind, I think that :

> - How a vector can be a vector as with only 3 coordinates I only get a

> point. As a vector is a "direction" I need 3 others coordinates, no ?

If you want a vector with a definite start position

then you need both a vector and a coordinate, yes.

No, a vector is a direction in space, it has no position.Quote:> Do we presume that the start of the vector is 0,0,0 (the origin ??).

No. x,y and z are the components of the vector.Quote:> For example, when you write the len of a vector is "len = sqrt(x*x + y*y +

> z*z))"... Should I read len = sqrt(x1*x2 + y1*y2 + z1*z2)) when x1,y1,z1

> are the "start" of the the vector and x2,y2,z2 the "end" ???

The position is irrelevent. A vector can be anywhere

in space and the length won't change.

--

<\___/>

/ O O \

\_____/ FTB.

"fungus" schrieb im Newsbeitrag ...

> > May I ask you a question ?

> > In my newbie's mind, I think that :

> > - How a vector can be a vector as with only 3 coordinates I only get a

> > point. As a vector is a "direction" I need 3 others coordinates, no ?

> A vector is a direction, not a point.

> If you want a vector with a definite start position

> then you need both a vector and a coordinate, yes.

> > Do we presume that the start of the vector is 0,0,0 (the origin ??).

> No, a vector is a direction in space, it has no position.

> > For example, when you write the len of a vector is "len = sqrt(x*x + y*y

+

> > z*z))"... Should I read len = sqrt(x1*x2 + y1*y2 + z1*z2)) when x1,y1,z1

> > are the "start" of the the vector and x2,y2,z2 the "end" ???

> No. x,y and z are the components of the vector.

> The position is irrelevent. A vector can be anywhere

> in space and the length won't change.

position is the x/y/z coordinate a thing has in a 3d area.

vector is a direction a thing is moving.

picture the following:

a highway with many automobiles on it.

although each automobile has a different position

they basicly all move in the same direction.

A1.Pos != A2.Pos

but A1.Dir == A2.Dir (approximatly)

(unless changing lanes)

there is a nice tutorial on www.gamedev.net

HTH!

cu

frank

With a coordinate triplet (x,y,z) you can define a point in a givenQuote:> In my newbie's mind, I think that :

> - How a vector can be a vector as with only 3 coordinates I only get a

> point. As a vector is a "direction" I need 3 others coordinates, no ?

> Do we presume that the start of the vector is 0,0,0 (the origin ??).

3-dimensional cartesian coordinate system. Every coordinate system has an

origin, and thus with a coordinate triplet we implicitly define a direction

in relation to that origin.

No, as I think I mentioned in the first part of my tutorial, that equationQuote:> For example, when you write the len of a vector is "len = sqrt(x*x + y*y +

> z*z))"... Should I read len = sqrt(x1*x2 + y1*y2 + z1*z2)) when x1,y1,z1

> are the "start" of the the vector and x2,y2,z2 the "end" ???

is the 3 dimensional counterpart of the pythagora's rule of the right

triangle (not sure if that's the name exactly but anyway). the lenght of the

hypotenuse is the sqare root of the sum of the sqare of the other sides: A =

sqrt(b^2 + c^2) now in 3D you also include z^2 to that sum (take a loog at

my diagram). so in fact since the angle between the x and y axis is

90degrees, we can consider the vector at hand as the hypotense of a right

triangle that has as its other sides its distance from the y axis and from

the x axis (x and y component). Really look at that diagram, it should be

obvious once you think of it.

not at all, if you need anything else just ask.Quote:> Ahem... Don't want to abuse but some another help would be greatly

> appreciated ;-)

-- Nuclear / the Lab --

--

Check that new website bout' MATRIX!!!!!!!!!!!!!!!!!!!!

http://perso.wanadoo.fr/guenaels

http://perso.wanadoo.fr/guenaels

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