Bullet object - GameCreators Forum

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Derekioh

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Posted: 10th Sep 2009 19:19

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Hey, i'm working on a FPS and i was wondering how you would make an object that would shoot and hit an enemy and then return to the same position before you shot the bullet.

thx in advance

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Zotoaster

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Posted: 10th Sep 2009 20:59

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Don't use objects for bullets. The reason is that you're going to need them to move really fast, and to do that, they have to basically 'skip' positions. The faster they move, the less chance they have of actually intersecting your enemy, even if you shoot right at it.

To tackle this, use raycasting, using Sparky's Collision DLL, or the slower built in 'Intersect Object' command.

"everyone forgets a semi-colon sometimes." - Phaelax

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Derekioh

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Posted: 11th Sep 2009 19:20

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ok, i have sparky but i never thought to use raycasting (since i've only programmed for like a year). By the way, if you use intersect object or raycasting, how would u slow the firing rate (EX: i have a shotgun and its just keeps shooting and i want it to shoot 1 shot per second).

Thx

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BowserYo

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Posted: 12th Sep 2009 06:17 Edited at: 12th Sep 2009 06:24

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I think you would do something like this:

+ Code Snippet

actual_delay = 1000 `This is the actual time between shots (1000 = 1 second)
If mouseclick()=1 and shoot_delay <= timer() `If mouse is clicked and the it has been longer that the shoot delay_timer
  shoot_delay = timer()+ actual_delay `specifies how long the shoot_delay timery `specifies how long the shoot_delay timer is
  [insert shooting code here]
endif

Here is a small demo, check it out:

+ Code Snippet

sync on : sync rate 60
backdrop on : color backdrop 0

shots = 0
actual_delay = 1000

Do
   Set cursor 10,10 : Print shots
   Gosub shot
Sync
Loop

shot:
   if mouseclick()=1 and shot_delay <= timer()
      shot_delay = timer() + actual_delay
      inc shots,1
   endif
Return

I'm newer to programming than you are, butI think that should do the trick.

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z_man

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Posted: 12th Sep 2009 07:22 Edited at: 19th Sep 2009 03:17

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If you have sparky's, you can use something like so:

+ Code Snippet

x1# = Camera Position X( )
y1# = Camera Position Y( )
z1# = Camera Position Z( )
Move Camera 10000
x2# = Object Position X( )
y2# = Object Position Y( )
z2# = Object Position Z( )
Move Camera -10000
_resC = sc_MultipleRayCast( 0, x1#, y1#, z1#, x2#, y2#, z2#, 0 )
For i = 0 To _resC
   rem You can now get data for each collision along the ray
   rem The following line gets the object number and stores it in _hit
   _hit = sc_GetObjectHit( hObj )
Next i

This code is partially untested (modified from a project of mine). Hope it helps!

EDIT: Sorry, I should explain how it works. First, the camera position is stored in the x1#, y1# and z1# variables. Then the camera is moved far into the distance (as if it were the bullet). The new position is recorded in the x2#, y2# and z2# variables. The camera is then put back to where it started. Now we have two coordinates - both of these can be used to cast a ray and return any collisions along the way. The For...Next loop goes through each collision and returns the object. Other commands in sparky's DLL can be used to get other useful information (such as normals, etc).

If you're having troubles with all this, I'll try to explain further - it can be hard to grasp at first.

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chafari

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Posted: 13th Sep 2009 01:38

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hallo friends

Of course we can use raycasting using Sparky's Collision DLL, or the 'Intersect Object' command as Zotoaster says, but what about if we are so romantic that we want to use the old way of an object flying straight ahead ?

Here I have a piece of code I hope it can help some one...

autocam off:hide mouse
create bitmap 1,50,50:for i= 1 to 1550:ink rgb(30,255,55),0:line rnd(60),i,i,rnd(130)
next i:blur bitmap 1,6:get image 1,10,10,50,50:delete bitmap 1

sync on
arma=20 //gun
bala=21 //bullet
make object box 1,3000,1,3000
texture object 1,1
scale object texture 1,3,3

make object box arma,1.2,1.2,18
make object box bala,1,1,20:color object bala,rgb(200,0,0):hide object bala
make object sphere 3,50:color object 3,rgb(255,255,0)
position object 3,600,25,600

do
gosub _controla_camara
gosub bala
if object collision(bala,3)=1 then position object 3,300+rnd(1000),25,300+rnd(1000)
sync
loop

_controla_camara:
rem Controla la cámara con las teclas de flechas(alante y atras )
if upkey()=1 then x#=newxvalue(x#,a#,1) : z#=newzvalue(z#,a#,1)
if downkey()=1 then x#=newxvalue(x#,a#,-1) : z#=newzvalue(z#,a#,-1)

`nos desplazamos lateralmente a la izquierda (cursor derecho)
if leftkey()=1 THEN x#=NEWXVALUE(x#,a#-90,1)
if leftkey()=1 then z#=NEWZVALUE(z#,a#-90,1)
`nos desplazamos lateralmente a la derecha (cursor izquierdo)
if rightkey()=1 THEN x#=NEWXVALUE(x#,a#-90,-1)
if rightkey()=1 then z#=NEWZVALUE(z#,a#-90,-1)

`limitamos el subir y bajar la cabeza con el raton(vista de camara)
if cam#<=290 and cam#>180 then cam#=290
if cam#>=70 and cam#<180 then cam#=70
a#=wrapvalue(a#+mousemovex())
cam#=wrapvalue(cam#+mousemovey())
rotate camera cam#,a#,0
rem posicion de la camara mas el arma y el objeto bala
position camera x#,145,z#
position object arma,x#,145,z#
position object bala,x#,145,z#

rotate object arma,cam#,a#,0
rotate object bala,cam#,a#,0

move object arma,15
move object right arma,3
move object down arma,3

move object bala,15
move object right bala,3
move object down bala,3

return

bala:
set cursor 310,235:ink rgb(255,0,0),0
print " +"
`-------------------------------------------------------------
`HACEMOS QUE EL OBJETO BALA, SALGA DESDE EL ARMA
if dispara=0
set object to object orientation bala,arma
endif
if mouseclick() and dispara=0
dispara=1
show object bala
endif

if dispara=1
la=la+10
run=run+1
move object bala,la
endif

if run>200
run=0
la=0
dispara=0
hide object bala
endif
return
`-------------------------------------------------------------

+ Code Snippet

autocam off:hide mouse
create bitmap 1,50,50:for i= 1 to 1550:ink rgb(30,255,55),0:line rnd(60),i,i,rnd(130)
next i:blur bitmap 1,6:get image 1,10,10,50,50:delete bitmap 1

sync on
arma=20 //gun
bala=21 //bullet
make object box 1,3000,1,3000
texture object 1,1
scale object texture 1,3,3

make object box arma,1.2,1.2,18
make object box bala,1,1,20:color object bala,rgb(200,0,0):hide object bala
make object sphere 3,50:color object 3,rgb(255,255,0)
position object 3,600,25,600

do
gosub _controla_camara
gosub bala
if object collision(bala,3)=1 then position object 3,300+rnd(1000),25,300+rnd(1000)
sync
loop

_controla_camara:
rem Controla la cámara con las teclas de flechas(alante y atras )
if upkey()=1 then x#=newxvalue(x#,a#,1) : z#=newzvalue(z#,a#,1)
if downkey()=1 then x#=newxvalue(x#,a#,-1) : z#=newzvalue(z#,a#,-1)

`nos desplazamos lateralmente a la izquierda (cursor derecho)
if leftkey()=1 THEN x#=NEWXVALUE(x#,a#-90,1)
if leftkey()=1 then z#=NEWZVALUE(z#,a#-90,1)
`nos desplazamos lateralmente a la derecha (cursor izquierdo)
if rightkey()=1 THEN x#=NEWXVALUE(x#,a#-90,-1)
if rightkey()=1 then z#=NEWZVALUE(z#,a#-90,-1)


`limitamos el subir y bajar la cabeza con el raton(vista de camara)
if cam#<=290 and cam#>180 then cam#=290
if cam#>=70 and cam#<180 then cam#=70
a#=wrapvalue(a#+mousemovex())
cam#=wrapvalue(cam#+mousemovey())
rotate camera cam#,a#,0
rem posicion de la camara mas el arma y el objeto bala
position camera x#,145,z#
position object arma,x#,145,z#
position object bala,x#,145,z#

rotate object arma,cam#,a#,0
rotate object bala,cam#,a#,0

move object arma,15
move object right arma,3
move object down arma,3

move object bala,15
move object right bala,3
move object down bala,3


return

bala:
set cursor 310,235:ink rgb(255,0,0),0
print " +"
`-------------------------------------------------------------
`HACEMOS QUE EL OBJETO BALA, SALGA DESDE EL ARMA
if dispara=0
set object to object orientation bala,arma
endif
if mouseclick() and dispara=0
dispara=1
show object bala
endif

if dispara=1
la=la+10
run=run+1
move object bala,la
endif

if run>200
run=0
la=0
dispara=0
hide object bala
endif
return
`-------------------------------------------------------------

oh my god

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Derekioh

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Posted: 14th Sep 2009 18:19

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thx, i'll test out this stuff today and i'll see if i need any more help.

thx again

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BowserYo

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Posted: 16th Sep 2009 22:55 Edited at: 16th Sep 2009 23:02

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@ Z_Man, what is the "ObjT" for?

When I run your code as-is it gives me an error saying ObjT does not exist.

Are the x2,y2,z2 suppose to equal "camera position x" not object position x?

When I change it to:

+ Code Snippet

      x1# = Camera Position X( 0 )
      y1# = Camera Position Y( 0 )
      z1# = Camera Position Z( 0 )
      Move Camera 10000
      x2# = Camera Position X( 0 )
      y2# = Camera Position Y( 0 )
      z2# = Camera Position Z( 0 )
      Move Camera -10000
      resC = sc_MultipleRayCast( 0, x1#, y1#, z1#, x2#, y2#, z2#, 0 )
   For i = 0 To _resC
         rem You can now get data for each collision along the ray
         rem The following line gets the object number and stores it in _hit
      _hit = sc_GetObjectHit( hObj )
   Next i

It returns a number like 700000000 and the number just stays it doesn't revert back to 0. Help?

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Kira Vakaan

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Posted: 17th Sep 2009 22:10

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chafari: Yes, we could do that, but as Zotoaster pointed out, that method has some pretty problematic consequences. In your example it works fine, because the thing you're shooting at is longer than the speed of the bullet, and so it's impossible for the bullet to "skip over" the sphere, but the bullet in your example is a little slow for something you'd actually use in an FPS. Try changing the speed of the bullet to 150.

Of course, you could be completely aware of this issue and I'm just preaching to the choir, in which case, I apologize.

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BowserYo

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Posted: 18th Sep 2009 16:12

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I think I figured it out. Tell me if this is right? It seems to work in that demo, but when I try to transfer the code to my other project it doesn't work so well (only returns a really big number starting with 7).

Rem Project: raycast_test
Rem Created: 9/16/2009 3:37:21 PM

Rem ***** Main Source File *****
Print "Loading..." : Sync : CLS : Autocam off
`Setup
Sync on : sync rate 60
Backdrop on : Color backdrop rgb(0,0,50)
Set camera range 10,20000

Goto MakeMedia

MainLoop:
Do
   Gosub Controls
   Gosub Raycast
   Gosub Stats
Sync : Loop

Controls:
   Position mouse screen width()/2, screen height()/2
   `Control player
      if upkey()=1 then x#=newxvalue(x#,a#,10.0) : z#=newzvalue(z#,a#,10.0)
      if downkey()=1 then x#=newxvalue(x#,a#,-10.0) : z#=newzvalue(z#,a#,-10.0)
      if leftkey()=1 then a#=wrapvalue(a#-3.0)
      if rightkey()=1 then a#=wrapvalue(a#+3.0)
      y#=get ground height(1,x#,z#)+(object size y(1))/2
      position object 1,x#,y#,z#
      yrotate object 1,wrapvalue(a#)

`Camera control
      ca#=wrapvalue(curveangle(a#,ca#,10.0))
      cx#=newxvalue(x#,ca#,-500)
      cz#=newzvalue(z#,ca#,-500)
      cy#=y#+300
      position camera cx#,cy#,cz#
      yrotate camera wrapvalue(ca#)
      point camera x#,y#,z#
Return

RayCast:
If mouseclick()
      `Get's position of player
      x1# = Object Position X( player )
      y1# = Object Position Y( player )
      z1# = Object Position Z( player )

`Moves the raycast reference object 10,000 units away from player in direction he is looking
      Position Object 25, Object Position X( player ), Object Position Y( player ), Object Position Z( player )
      Rotate Object 25, Object Angle X( player ), Object Angle Y( player ), Object Angle Z( player )
      Move Object 25, 10000

`Get's position object raycast reference object (10,000 units away in the direction your looking)
      x2# = Object Position X( 25 )
      y2# = Object Position Y( 25 )
      z2# = Object Position Z( 25 )

`Makes a "ray" or "line" between player and the raycast reference object
      raycast = sc_MultipleRayCast( 0, x1#, y1#, z1#, x2#, y2#, z2#, 0 )
   For i = 0 To raycast
      `ObjectHit = object hit by the ray/line
      ObjectHit = sc_GetObjectHit( hObj )
   Next i
endif
Return

Stats:
   Set cursor 10,10 : Print "FPS: ", Screen FPS()
   Set cursor 10,25 : Print "Raycast: ", ObjectHit
Return

MakeMedia:
   player=1 : Make object cube player,100 `Player
   Make matrix 1,10000,10000,25,25 `Matrix, creates a visible grid
   Make object cube 10,25 : position object 10, 1000,50,1000
   Make object cube 11,100 : position object 11, 500,50,500
   Sc_SetupObject 11,1,0
   `raycast obj
   make object cube 25, 25
Goto MainLoop

+ Code Snippet

Rem Project: raycast_test
Rem Created: 9/16/2009 3:37:21 PM

Rem ***** Main Source File *****
Print "Loading..." : Sync : CLS : Autocam off
`Setup
Sync on : sync rate 60
Backdrop on : Color backdrop rgb(0,0,50)
Set camera range 10,20000

Goto MakeMedia

MainLoop:
Do
   Gosub Controls
   Gosub Raycast
   Gosub Stats
Sync : Loop

Controls:
   Position mouse screen width()/2, screen height()/2
   `Control player
      if upkey()=1 then x#=newxvalue(x#,a#,10.0) : z#=newzvalue(z#,a#,10.0)
      if downkey()=1 then x#=newxvalue(x#,a#,-10.0) : z#=newzvalue(z#,a#,-10.0)
      if leftkey()=1 then a#=wrapvalue(a#-3.0)
      if rightkey()=1 then a#=wrapvalue(a#+3.0)
      y#=get ground height(1,x#,z#)+(object size y(1))/2
      position object 1,x#,y#,z#
      yrotate object 1,wrapvalue(a#)

   `Camera control
      ca#=wrapvalue(curveangle(a#,ca#,10.0))
      cx#=newxvalue(x#,ca#,-500)
      cz#=newzvalue(z#,ca#,-500)
      cy#=y#+300
      position camera cx#,cy#,cz#
      yrotate camera wrapvalue(ca#)
      point camera x#,y#,z#
Return

RayCast:
If mouseclick()
      `Get's position of player
      x1# = Object Position X( player )
      y1# = Object Position Y( player )
      z1# = Object Position Z( player )

      `Moves the raycast reference object 10,000 units away from player in direction he is looking
      Position Object 25, Object Position X( player ), Object Position Y( player ), Object Position Z( player )
      Rotate Object 25, Object Angle X( player ), Object Angle Y( player ), Object Angle Z( player )
      Move Object 25, 10000

      `Get's position object raycast reference object (10,000 units away in the direction your looking)
      x2# = Object Position X( 25 )
      y2# = Object Position Y( 25 )
      z2# = Object Position Z( 25 )

      `Makes a "ray" or "line" between player and the raycast reference object
      raycast = sc_MultipleRayCast( 0, x1#, y1#, z1#, x2#, y2#, z2#, 0 )
   For i = 0 To raycast
      `ObjectHit = object hit by the ray/line
      ObjectHit = sc_GetObjectHit( hObj )
   Next i
endif
Return

Stats:
   Set cursor 10,10 : Print "FPS: ", Screen FPS()
   Set cursor 10,25 : Print "Raycast: ", ObjectHit
Return

MakeMedia:
   player=1 : Make object cube player,100 `Player
   Make matrix 1,10000,10000,25,25 `Matrix, creates a visible grid
   Make object cube 10,25 : position object 10, 1000,50,1000
   Make object cube 11,100 : position object 11, 500,50,500
   Sc_SetupObject 11,1,0
   `raycast obj
   make object cube 25, 25
Goto MainLoop

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chafari

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Location: Canary Islands

Posted: 18th Sep 2009 21:57

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You are right Kira Vacaan but actually when we shoot, the bullet doesn`t hit immediately,unless we a so close to it, as it takes some milliseconds of second to reach the end of its power.When we do it by the method of intersect object,Sometimes, hit several objects at the same time and we have to write conditions to avoid to kill more than one enemy at a time.
About speed of the bullet, ha ha...you check this handicap...that is truth..., just to give a chance to the enemies to scape.
I use differents methods .As z_man pointed out we can use the camera position and move it hundreds of units ahead to get all coordinates x,y,z new_x,new_y,new_z and finally use an intersect object to use as the bulles.

Here is another example.

autocam off:hide mouse
sync on
make light 1:position light 1,0,150,0
make object box 3,2,2,2:color object 3,rgb(0,0,0)
make object box 100,400,1,400:color object 100,rgb(100,70,30) //suelo
`-----------------------------------------------------------
make object box 101,30,30,30:position object 101,100,30,200
make object box 102,30,30,30: position object 102,60,30,-190
make object box 103,30,30,30:position object 103,0,30,-190
make object box 104,30,30,30: position object 104,-60,30,-190

do
if upkey()=1 then x#=newxvalue(x#,a#,1) : z#=newzvalue(z#,a#,1)
if downkey()=1 then x#=newxvalue(x#,a#,-1) : z#=newzvalue(z#,a#,-1)

ink rgb(255,0,0),1:set cursor 319,235:print "+" // foresight
//starting camera position
x=camera position x()
y=camera position y()
z=camera position z()

if mouseclick()
  move camera 1000
  //end camera position 
  nx=camera position x()
  ny=camera position y()
  nz=camera position z()
endif

// we check the distance to the reached object
for i= 100 to 104
  if intersect object(i,x,y,z,nx,ny,nz)>0
    distancia#=intersect object(i,x,y,z,nx,ny,nz)
  endif
next i

set cursor 5,5
print "DISTANCE OF HIT:   ", distancia#,"m"

// camera controls
rotate camera cam#,a#,0
position camera x#,55,z#
a#=wrapvalue(a#+mousemovex()/2)
cam#=wrapvalue(cam#+mousemovey()/2)
if cam#<=290 and cam#>180 then cam#=290
if cam#>=70 and cam#<180 then cam#=70

//we check which object is being hit
if mouseclick()
   for i= 100 to 104
      if intersect object(i,x,y,z,nx,ny,nz)>0
         position object 3,x#,55,z#
         rotate object 3,cam#,a#,0
         move object 3,distancia#
      endif
   next i
endif

if mouseclick()
   for i= 101 to 104
      if intersect object(i,x,y,z,nx,ny,nz)>0
         color object i,rgb(0,0,255): position object i,object   position x(i),30+rnd(2),object position z(i)
         SET CURSOR 200,215:PRINT "LE HAZ DADO AL CUBO    ",I-(100)
         else color object i,rgb(255,255,255)
      endif
   next i
endif

sync
loop

+ Code Snippet

autocam off:hide mouse
sync on
make light 1:position light 1,0,150,0
make object box 3,2,2,2:color object 3,rgb(0,0,0)
make object box 100,400,1,400:color object 100,rgb(100,70,30) //suelo
`-----------------------------------------------------------
make object box 101,30,30,30:position object 101,100,30,200
make object box 102,30,30,30: position object 102,60,30,-190
make object box 103,30,30,30:position object 103,0,30,-190
make object box 104,30,30,30: position object 104,-60,30,-190


do
if upkey()=1 then x#=newxvalue(x#,a#,1) : z#=newzvalue(z#,a#,1)
if downkey()=1 then x#=newxvalue(x#,a#,-1) : z#=newzvalue(z#,a#,-1)


ink rgb(255,0,0),1:set cursor 319,235:print "+" // foresight
//starting camera position
x=camera position x()
y=camera position y()
z=camera position z()

if mouseclick()
  move camera 1000
  //end camera position 
  nx=camera position x()
  ny=camera position y()
  nz=camera position z()
endif

// we check the distance to the reached object
for i= 100 to 104
  if intersect object(i,x,y,z,nx,ny,nz)>0
    distancia#=intersect object(i,x,y,z,nx,ny,nz)
  endif
next i

set cursor 5,5
print "DISTANCE OF HIT:   ", distancia#,"m"

// camera controls
rotate camera cam#,a#,0
position camera x#,55,z#
a#=wrapvalue(a#+mousemovex()/2)
cam#=wrapvalue(cam#+mousemovey()/2)
if cam#<=290 and cam#>180 then cam#=290
if cam#>=70 and cam#<180 then cam#=70

//we check which object is being hit
if mouseclick()
   for i= 100 to 104
      if intersect object(i,x,y,z,nx,ny,nz)>0
         position object 3,x#,55,z#
         rotate object 3,cam#,a#,0
         move object 3,distancia#
      endif
   next i
endif

if mouseclick()
   for i= 101 to 104
      if intersect object(i,x,y,z,nx,ny,nz)>0
         color object i,rgb(0,0,255): position object i,object   position x(i),30+rnd(2),object position z(i)
         SET CURSOR 200,215:PRINT "LE HAZ DADO AL CUBO    ",I-(100)
         else color object i,rgb(255,255,255)
      endif
   next i
endif

sync
loop

oh my god

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z_man

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Posted: 19th Sep 2009 03:17 Edited at: 19th Sep 2009 03:19

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Quote: "@ Z_Man, what is the "ObjT" for?"

Wow, sorry about that, my mistake. You can just get rid of objT and leave empty brackets. In my project I was actually using objects to mark the two raycasting points.

EDIT: I've modified the code I posted above - hopefully it will work now.

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