[Aooka]

Extremely well explained !! Thanks a lot !

Without you I will not understood

[pokemonmaster]

I'm still confused with coordinates and angles.

In your wall text plugin you have this

PHP Code:

    // lengthen vector and move it to user's origin
    fAimVector[0] = fAimVector[0] * 9999.0 + fPlayerOrigin[0]
    fAimVector[1] = fAimVector[1] * 9999.0 + fPlayerOrigin[1]
    fAimVector[2] = fAimVector[2] * 9999.0 + fPlayerOrigin[2] 


Why did you multipy fAimVector in 9999 and then add to it the player origin, I could not understand this even with the comment you have written, could some one explain it to me?

[Arkshine]

It multiplies by 9999 to get a vector length as big as possible.
It adds to player's origin, since we want this "long line" starts at player's origin.

[pokemonmaster]

Originally Posted by Arkshine It multiplies by 9999 to get a vector length as big as possible. It adds to player's origin, since we want this "long line" starts at player's origin.

Thanks for the fast reply, but if we multiply it by 9999 to get the biggest vector as possible, why would we add it to the player origin if it won't make any difference

PHP Code:

// Lets assume this
new Float:vOrigin[3] = { 234.4, -251.0, 100.0 }
new Float:vAimVector[3] = { 151.128, 390.15, 285.25 }

xs_vec_mul_scalar(vAimVector, 9999.0, vAimVector)
xs_vec_add(vAimVector, vOrigin, vAimVector)

// At last, vAimVector will be
// { 1511363.272, 3900858.85, 2852314.75 }
// And that's far from what you have said about ->
// It adds to player's origin, since we want this "long line" starts at player's origin

new iTr = create_tr2()
engfunc( EngFunc_TraceLine, vOrigin, vAimVector, IGNORE_MONSTERS, id, iTr )
free_tr2(iTr) 


I hope you understood my point

[Arkshine]

The purpose of a TraceLine is to trace a virtual line from point A to point B and seeing if it hits something.

To make a line, you need to know the Point A origin, and the Point B origin.

We know already player's origin, which is Point A (vOrigin).

To know the end origin, which is Point B, you need a direction and a length.

Length and direction you will want to apply from Point A.

A           B
x---------->x
|   length  |

Since we don't care about length, you multiply the direction by a big number like 9999. (You could also use 8192 which is the max length of a map)

So you have "a long line" with a defined direction.To know the Point B origin, you just need to start the line from Point A.

That's why you add the Point A origin to this "long line". You need to tell from where you want to start to draw the line.

[pokemonmaster]

Originally Posted by Arkshine That's why you add the Point A origin to this "long line". You need to tell from where you want to start to draw the line.

I'm still confused about this part lol
Isn't the start point of the trace line is the vOrigin?

I've got another question, multiplying the z position (hieght) for the vAimVector([2]) by 9999 would make the traceline go from point a to point c, what I'm trying to do is making a traceline between a and b



I understand why we multiplied the x and y origins.

[pokemonmaster]

Bump...

[hornet]

Originally Posted by pokemonmaster I've got another question, multiplying the z position (hieght) for the vAimVector([2]) by 9999 would make the traceline go from point a to point c, what I'm trying to do is making a traceline between a and b

The player's aim vector will always be the hypotenuse. Having said that, explain why you would only want to trace from a to b ?

[Sherazaa]

Hi, awesome tut ! Thanks a lot's.

I have got some questions to ask you about the last example :

PHP Code:

CreateNewMessage( id, szMessage[MESSAGE_LEN] )
{
    new Float:fAimOrigin[3]
    new Float:fPlayerOrigin[3]
    
    new Float:fAimVector[3]
    new Float:fNormalVector[3]
    new Float:fTextVector[3]
    
    // user's view angle
    pev( id, pev_v_angle, fAimVector )
    
    // vector pointing in that direction
    angle_vector( fAimVector, ANGLEVECTOR_FORWARD, fAimVector )
    
    // user's origin
    pev( id, pev_origin, fPlayerOrigin )
    
    // lengthen vector and move it to user's origin
    fAimVector[0] = fAimVector[0] * 9999.0 + fPlayerOrigin[0]
    fAimVector[1] = fAimVector[1] * 9999.0 + fPlayerOrigin[1]
    fAimVector[2] = fAimVector[2] * 9999.0 + fPlayerOrigin[2]
    
    // execute traceline, grab normal vector and end position
    new iTr = create_tr2()
    engfunc( EngFunc_TraceLine, fPlayerOrigin, fAimVector, IGNORE_MONSTERS, id, iTr )
    get_tr2( iTr, TR_vecEndPos, fAimOrigin )
    get_tr2( iTr, TR_vecPlaneNormal, fNormalVector )
    free_tr2( iTr )
    
    // convert normal vector to angles
    vector_to_angle( fNormalVector, fTextVector )
    
    // get vector pointing to the right, from the perspective of the normal vector
    angle_vector( fTextVector, ANGLEVECTOR_RIGHT, fTextVector )
    
    // lengthen by width of one character, and point towards the left (from the perspective of the normal vector)
    fTextVector[0] *= -1.0 * CHAR_WIDTH
    fTextVector[1] *= -1.0 * CHAR_WIDTH
    fTextVector[2] *= -1.0 * CHAR_WIDTH
    
    // ...
} 


So,

1/ I do not understand why you write that :

angle_vector( fAimVector, ANGLEVECTOR_FORWARD, fAimVector )

2/ And this part too :

new iTr = create_tr2()
engfunc( EngFunc_TraceLine, fPlayerOrigin, fAimVector, IGNORE_MONSTERS, id, iTr )
get_tr2( iTr, TR_vecEndPos, fAimOrigin )
get_tr2( iTr, TR_vecPlaneNormal, fNormalVector )
free_tr2( iTr )

3/ Why we must convert a normal vector to an angle ?

vector_to_angle( fNormalVector, fTextVector )

So here, i do not understand that ... :/

angle_vector( fTextVector, ANGLEVECTOR_RIGHT, fTextVector )

4/ And to finished, why you do that ?

fTextVector[ 0 ] *= - 1.0 * CHAR_WIDTH; // CHAR_WIDTH = 12 

So thanks in advance.

If someone can help me it would be really nice. I home somebody know how to explain those parts.

[pokemonmaster]

Originally Posted by hornet The player's aim vector will always be the hypotenuse. Having said that, explain why you would only want to trace from a to b ?

I'm making an laser mine plugin, I have succeeded putting it in the wall at first, but it wasn't on the wall exactly, but now I did it correctly, I understood angles positions more, thanks for your help all.