smart camera following, uses Newton physics wrapper to avoid collision with walls

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Physics coder

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Joined: 25th May 2004

Location: United States

Posted: 12th Jul 2004 00:41 Edited at: 12th Jul 2004 00:48

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You need the latest version of the Newton Physics wrapper and have the dll be in the same folder as you save this source too. no media required. The camera has an object and a body. the object follows the player, the camera is positioned at the object following the player and points at the player.

controls: WASD player movement (player is a box)
if the camera gets stuck, it goes up until it goes above the geometry.

rem acceleration variables
global accz#=300.0
global accyt#=1.0

rem screen stuff
set display mode 800,600,32
sync on
sync rate 0
autocam off
hide mouse

rem forget about this array, it's only called in functions
dim obj_move(1000)
`Three D Point in space, used for positions, velocities, etc (NOT USED BY NEWTON)
TYPE ThreeD
x as float
y as float
z as float
ENDTYPE
rem make textures
ink rgb(0,255,0),0
box 0,0,100,100
ink 0,0
box 2,2,98,98
sync
get image 1,0,0,100,100
rem and texture 2
cls
ink 0,0
box 0,0,100,100
ink rgb(200,200,200),0
box 1,1,9,9
sync
get image 2,0,0,10,10

rem set the camera range
set camera range 0.5,200
`make object cube 10000,0
TOP:

rem INITIALIZE PHYSICS WORLD!
global CURRENT_OBJECT
CURRENT_OBJECT=0
NDB_NewtonCreate

rem Materials
GroundID = NDB_NewtonMaterialCreateGroupID()
WallID = NDB_NewtonMaterialCreateGroupID()
CamID = NDB_NewtonMaterialCreateGroupID()
BOXID = NDB_NewtonMaterialCreateGroupID()
NDB_NewtonMaterialSetDefaultFriction CAMID, WallID, 0,0
NDB_NewtonMaterialSetDefaultElasticity CAMID, WallID, 0.001
NDB_NewtonMaterialSetDefaultSoftness CAMID, WallID, 0.1
NDB_NewtonMaterialSetDefaultFriction BOXID, GroundID, 0.7,0.4
NDB_NewtonMaterialSetDefaultElasticity BOXID, GroundID, 0.001
NDB_NewtonMaterialSetDefaultSoftness BOXID, GroundID, 0.1
rem world:
rem floor
inc CURRENT_OBJECT : make_box(CURRENT_OBJECT,100,10,100,50,-5,50,0,0,0,1,GroundID,0,1)
texture object CURRENT_OBJECT, 1
rem walls
inc CURRENT_OBJECT : make_box(CURRENT_OBJECT,100,50,10,50,15,105,0,0,0,10,WallID,0,1)
texture object CURRENT_OBJECT, 2
inc CURRENT_OBJECT : make_box(CURRENT_OBJECT,100,50,10,50,15,-5,0,0,0,10,WallID,0,1)
texture object CURRENT_OBJECT, 2
inc CURRENT_OBJECT : make_box(CURRENT_OBJECT,10,50,100,105,15,50,0,0,0,10,WallID,0,1)
texture object CURRENT_OBJECT, 2
inc CURRENT_OBJECT : make_box(CURRENT_OBJECT,10,50,100,-5,15,50,0,0,0,10,WallID,0,1)
texture object CURRENT_OBJECT, 2
rem boxes
for n=1 to 30
inc CURRENT_OBJECT : make_box(CURRENT_OBJECT,2+rnd(8),4+rnd(6),2+rnd(8),rnd(80)+10,3,rnd(80)+10,0,rnd(359),0,10000,WallID,1,1)
texture object CURRENT_OBJECT, 2
next n

rem player
inc CURRENT_OBJECT
player_body=make_box(CURRENT_OBJECT,3,2,4,50,1,50,0,0,0,2,BOXID,1,0)
player_num=CURRENT_OBJECT
texture object CURRENT_OBJECT, 2

rem camera
inc CURRENT_OBJECT
CAM_BODY=make_sphere(CURRENT_OBJECT,10,50,20,50,0.01,CamID,1,0)
CAM_OBJECT=CURRENT_OBJECT
hide object CAM_OBJECT

global time#
repeat
   time# = NDB_GetElapsedTimeInSec()
until time# < 0.1

do

time# = NDB_GetElapsedTimeInSec()

NDB_NewtonUpdate time#
rem display
   ink rgb(0,255,0),0
   text 10,10,"-------------------------------------------------------------"
   text 10,20,"Newton Game Dynamics SDK DBPro Wrapper v"+str$(NDB_GetVersion())
   text 10,40,"Smart camera follow, camera avoids objects"
   text 10,50,"Control box with W/A/S/D"
   text 10,60,"Reset by using the r key."
   text 10,70,"FPS "+str$(screen fps())
   text 10,80,"-------------------------------------------------------------"
   set cursor 0,100

if inkey$() = "r"
      NDB_NewtonDestroy
      goto TOP
   endif

rem control the box
   zmove=keystate(17)-keystate(31)
   yturn=keystate(32)-keystate(30)
   `print scancode()
   point camera object position x(player_num),object position y(player_num),object position z(player_num)
   x1#=object position x(player_num)
   y1#=object position y(player_num)
   z1#=object position z(player_num)
   rem get relative z axis
   move object player_num,1
   zx#=object position x(player_num)-x1#
   zy#=object position y(player_num)-y1#
   zz#=object position z(player_num)-z1#
   move object player_num,-1
rem move forward
   NDB_NewtonBodyGetVelocity player_body
   x#=zmove*zx#*accz#*time#
   z#=zmove*zz#*accz#*time#
   NDB_SetVector NDB_GetVector_x(1)*0.7+x#,0, NDB_GetVector_z(1)*0.7+z#
   NDB_NewtonBodySetVelocity player_body

yangle#=atanfull(zx#,zz#)
rem turn
NDB_NewtonBodyGetOmega player_body
NDB_SetVector NDB_GetVector_x(1), NDB_GetVector_Y(1)*0.7+yturn*accyt#,NDB_GetVector_z(1)
NDB_NewtonBodySetOmega player_body

rem control the camera:
   dist#=8
rem if the camera gets stuck, increase th height until it gets over the wall,
rem and hope there's no ceiling

height#=SQRT((object position x(CAM_OBJECT)-fx#)^2+(object position z(CAM_OBJECT)-fz#)^2)
   oay#=yangle#
   opx#=object position x(player_num)
   opy#=object position y(player_num)
   opz#=object position z(player_num)
   fx#=opx#-dist#*sin(oay#)
   fy#=opy#+height#
   fz#=opz#-dist#*cos(oay#)
rem fx#,fy#,fz# is the place where the camera WANTS to be
   curve#=3
   cx#=camera position x()
   cy#=camera position y()
   cz#=camera position z()
rem slowly move the camera there

x#=(fx#-object position x(CAM_OBJECT))*curve#
   y#=(fy#-object position y(CAM_OBJECT))*curve#
   z#=(fz#-object position z(CAM_OBJECT))*curve#
   NDB_SetVector x#, y#, z#
   NDB_NewtonBodySetVelocity CAM_BODY

rem position the camera
   position camera object position x(CAM_OBJECT),object position y(CAM_OBJECT),object position z(CAM_OBJECT)
   point camera object position x(player_num),object position y(player_num),object position z(player_num)

sync
loop

rem Destory the Physics world and all bodies in it.
NDB_NewtonDestroy

end

function make_box(obj_num,xs#,ys#,zs#,xp#,yp#,zp#,xr#,yr#,zr#,mass#,group_id,move,freeze)
   make object box obj_num, xs#,ys#,zs#
   position object obj_num, xp#,yp#,zp#
   col = NDB_NewtonCreateBox(xs#,ys#,zs#)
   body=NDB_NewtonCreateBody(col)
   NDB_BodySetDBProData body, obj_num
   NDB_SetVector xr#,yr#,zr#
   NDB_SetVectorToRadians
   NDB_NewtonSetEulerAngle
   NDB_SetVector xp#, yp#, zp#, 1.0
   NDB_SetMatrixPosRow
   NDB_NewtonBodySetMatrix body
   NDB_NewtonBodySetAutoFreeze body, freeze
   NDB_NewtonBodySetDestructorCallback body
   NDB_NewtonBodySetMaterialGroupID body, group_id
   NDB_NewtonBodySetTransformCallback body
   if move=1
      NDB_SetVector 0.0, 0.0, 0.0
      NDB_NewtonBodySetVelocity body
   NDB_NewtonBodySetForceAndTorqueCallback body
   NDB_CalculateMIBoxSolid mass#,xs#,ys#,zs#
   NDB_NewtonBodySetMassMatrix Body, mass#
endif
obj_move(body)=move
endfunction body

function make_sphere(obj_num,s#,xp#,yp#,zp#,mass#,group_id,move,freeze)
   make object sphere obj_num, s#
   position object obj_num, xp#,yp#,zp#
   col = NDB_NewtonCreateSphere(s#*0.5)
   body=NDB_NewtonCreateBody(col)
   NDB_BodySetDBProData body, obj_num
   NDB_SetMatrixIdentityMatrix
   NDB_SetVector xp#, yp#, zp#, 1.0
   NDB_SetMatrixPosRow
   NDB_NewtonBodySetMatrix body
   NDB_NewtonBodySetAutoFreeze body, freeze
   NDB_NewtonBodySetDestructorCallback body
   NDB_NewtonBodySetMaterialGroupID body, group_id
      NDB_NewtonBodySetTransformCallback body
   if move=1
      NDB_SetVector 0.0, 0.0, 0.0
      NDB_NewtonBodySetVelocity body
      NDB_NewtonBodySetForceAndTorqueCallback body
      NDB_CalculateMISphereHollow mass#,radius#
      NDB_NewtonBodySetMassMatrix Body, mass#
   endif
   obj_move(body)=move
endfunction body

+ Code Snippet

rem acceleration variables
global accz#=300.0
global accyt#=1.0


rem screen stuff
set display mode 800,600,32
sync on
sync rate 0
autocam off
hide mouse

rem forget about this array, it's only called in functions
dim obj_move(1000)
`Three D Point in space, used for positions, velocities, etc (NOT USED BY NEWTON)
TYPE ThreeD
x as float
y as float
z as float
ENDTYPE
rem make textures
ink rgb(0,255,0),0
box 0,0,100,100
ink 0,0
box 2,2,98,98
sync
get image 1,0,0,100,100
rem and texture 2
cls
ink 0,0
box 0,0,100,100
ink rgb(200,200,200),0
box 1,1,9,9
sync
get image 2,0,0,10,10

rem set the camera range
set camera range 0.5,200
`make object cube 10000,0
TOP:

rem INITIALIZE PHYSICS WORLD!
global CURRENT_OBJECT
CURRENT_OBJECT=0
NDB_NewtonCreate

rem Materials
GroundID = NDB_NewtonMaterialCreateGroupID()
WallID = NDB_NewtonMaterialCreateGroupID()
CamID = NDB_NewtonMaterialCreateGroupID()
BOXID = NDB_NewtonMaterialCreateGroupID()
NDB_NewtonMaterialSetDefaultFriction CAMID, WallID, 0,0
NDB_NewtonMaterialSetDefaultElasticity CAMID, WallID, 0.001
NDB_NewtonMaterialSetDefaultSoftness CAMID, WallID, 0.1
NDB_NewtonMaterialSetDefaultFriction BOXID, GroundID, 0.7,0.4
NDB_NewtonMaterialSetDefaultElasticity BOXID, GroundID, 0.001
NDB_NewtonMaterialSetDefaultSoftness BOXID, GroundID, 0.1
rem world:
rem floor
inc CURRENT_OBJECT : make_box(CURRENT_OBJECT,100,10,100,50,-5,50,0,0,0,1,GroundID,0,1)
texture object CURRENT_OBJECT, 1
rem walls
inc CURRENT_OBJECT : make_box(CURRENT_OBJECT,100,50,10,50,15,105,0,0,0,10,WallID,0,1)
texture object CURRENT_OBJECT, 2
inc CURRENT_OBJECT : make_box(CURRENT_OBJECT,100,50,10,50,15,-5,0,0,0,10,WallID,0,1)
texture object CURRENT_OBJECT, 2
inc CURRENT_OBJECT : make_box(CURRENT_OBJECT,10,50,100,105,15,50,0,0,0,10,WallID,0,1)
texture object CURRENT_OBJECT, 2
inc CURRENT_OBJECT : make_box(CURRENT_OBJECT,10,50,100,-5,15,50,0,0,0,10,WallID,0,1)
texture object CURRENT_OBJECT, 2
rem boxes
for n=1 to 30
inc CURRENT_OBJECT : make_box(CURRENT_OBJECT,2+rnd(8),4+rnd(6),2+rnd(8),rnd(80)+10,3,rnd(80)+10,0,rnd(359),0,10000,WallID,1,1)
texture object CURRENT_OBJECT, 2
next n

rem player
inc CURRENT_OBJECT
player_body=make_box(CURRENT_OBJECT,3,2,4,50,1,50,0,0,0,2,BOXID,1,0)
player_num=CURRENT_OBJECT
texture object CURRENT_OBJECT, 2


rem camera
inc CURRENT_OBJECT
CAM_BODY=make_sphere(CURRENT_OBJECT,10,50,20,50,0.01,CamID,1,0)
CAM_OBJECT=CURRENT_OBJECT
hide object CAM_OBJECT

global time#
repeat
   time# = NDB_GetElapsedTimeInSec()
until time# < 0.1

do

   time# = NDB_GetElapsedTimeInSec()

   NDB_NewtonUpdate time#
rem display
   ink rgb(0,255,0),0
   text 10,10,"-------------------------------------------------------------"
   text 10,20,"Newton Game Dynamics SDK DBPro Wrapper v"+str$(NDB_GetVersion())
   text 10,40,"Smart camera follow, camera avoids objects"
   text 10,50,"Control box with W/A/S/D"
   text 10,60,"Reset by using the r key."
   text 10,70,"FPS "+str$(screen fps())
   text 10,80,"-------------------------------------------------------------"
   set cursor 0,100

   if inkey$() = "r"
      NDB_NewtonDestroy
      goto TOP
   endif

   rem control the box
   zmove=keystate(17)-keystate(31)
   yturn=keystate(32)-keystate(30)
   `print scancode()
   point camera object position x(player_num),object position y(player_num),object position z(player_num)
   x1#=object position x(player_num)
   y1#=object position y(player_num)
   z1#=object position z(player_num)
   rem get relative z axis
   move object player_num,1
   zx#=object position x(player_num)-x1#
   zy#=object position y(player_num)-y1#
   zz#=object position z(player_num)-z1#
   move object player_num,-1
rem move forward
   NDB_NewtonBodyGetVelocity player_body
   x#=zmove*zx#*accz#*time#
   z#=zmove*zz#*accz#*time#
   NDB_SetVector NDB_GetVector_x(1)*0.7+x#,0, NDB_GetVector_z(1)*0.7+z#
   NDB_NewtonBodySetVelocity player_body

   yangle#=atanfull(zx#,zz#)
rem turn
NDB_NewtonBodyGetOmega player_body
NDB_SetVector NDB_GetVector_x(1), NDB_GetVector_Y(1)*0.7+yturn*accyt#,NDB_GetVector_z(1)
NDB_NewtonBodySetOmega player_body


rem control the camera:
   dist#=8
rem if the camera gets stuck, increase th height until it gets over the wall,
rem and hope there's no ceiling

   height#=SQRT((object position x(CAM_OBJECT)-fx#)^2+(object position z(CAM_OBJECT)-fz#)^2)
   oay#=yangle#
   opx#=object position x(player_num)
   opy#=object position y(player_num)
   opz#=object position z(player_num)
   fx#=opx#-dist#*sin(oay#)
   fy#=opy#+height#
   fz#=opz#-dist#*cos(oay#)
rem fx#,fy#,fz# is the place where the camera WANTS to be
   curve#=3
   cx#=camera position x()
   cy#=camera position y()
   cz#=camera position z()
rem slowly move the camera there

   x#=(fx#-object position x(CAM_OBJECT))*curve#
   y#=(fy#-object position y(CAM_OBJECT))*curve#
   z#=(fz#-object position z(CAM_OBJECT))*curve#
   NDB_SetVector x#, y#, z#
   NDB_NewtonBodySetVelocity CAM_BODY

rem position the camera
   position camera object position x(CAM_OBJECT),object position y(CAM_OBJECT),object position z(CAM_OBJECT)
   point camera object position x(player_num),object position y(player_num),object position z(player_num)

   sync
loop

rem Destory the Physics world and all bodies in it.
NDB_NewtonDestroy

end



function make_box(obj_num,xs#,ys#,zs#,xp#,yp#,zp#,xr#,yr#,zr#,mass#,group_id,move,freeze)
   make object box obj_num, xs#,ys#,zs#
   position object obj_num, xp#,yp#,zp#
   col = NDB_NewtonCreateBox(xs#,ys#,zs#)
   body=NDB_NewtonCreateBody(col)
   NDB_BodySetDBProData body, obj_num
   NDB_SetVector xr#,yr#,zr#
   NDB_SetVectorToRadians
   NDB_NewtonSetEulerAngle
   NDB_SetVector xp#, yp#, zp#, 1.0
   NDB_SetMatrixPosRow
   NDB_NewtonBodySetMatrix body
   NDB_NewtonBodySetAutoFreeze body, freeze
   NDB_NewtonBodySetDestructorCallback body
   NDB_NewtonBodySetMaterialGroupID body, group_id
   NDB_NewtonBodySetTransformCallback body
   if move=1
      NDB_SetVector 0.0, 0.0, 0.0
      NDB_NewtonBodySetVelocity body
   NDB_NewtonBodySetForceAndTorqueCallback body
   NDB_CalculateMIBoxSolid mass#,xs#,ys#,zs#
   NDB_NewtonBodySetMassMatrix Body, mass#
endif
obj_move(body)=move
endfunction body

function make_sphere(obj_num,s#,xp#,yp#,zp#,mass#,group_id,move,freeze)
   make object sphere obj_num, s#
   position object obj_num, xp#,yp#,zp#
   col = NDB_NewtonCreateSphere(s#*0.5)
   body=NDB_NewtonCreateBody(col)
   NDB_BodySetDBProData body, obj_num
   NDB_SetMatrixIdentityMatrix
   NDB_SetVector xp#, yp#, zp#, 1.0
   NDB_SetMatrixPosRow
   NDB_NewtonBodySetMatrix body
   NDB_NewtonBodySetAutoFreeze body, freeze
   NDB_NewtonBodySetDestructorCallback body
   NDB_NewtonBodySetMaterialGroupID body, group_id
      NDB_NewtonBodySetTransformCallback body
   if move=1
      NDB_SetVector 0.0, 0.0, 0.0
      NDB_NewtonBodySetVelocity body
      NDB_NewtonBodySetForceAndTorqueCallback body
      NDB_CalculateMISphereHollow mass#,radius#
      NDB_NewtonBodySetMassMatrix Body, mass#
   endif
   obj_move(body)=move
endfunction body

-----------------------------------
To delete the bug, delete the code.
Specs: Sony VAIO Laptop, Windows XP, P4 2.8Ghz, 512MB RAM, ATI Radeon 64MB video memory, DBP Upgrade 5.3.

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FXTC

20

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Joined: 3rd Jul 2004

Location: CzechRepublic

Posted: 30th Jul 2004 08:23

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very nice

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Juso

22

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Joined: 23rd Sep 2002

Location: Finland

Posted: 1st Aug 2004 01:30 Edited at: 1st Aug 2004 01:43

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Its so nice snippet that I made a mini game!
Here is screen

and exe in a zip (3 meg)

http://www.compopus.fi/towers.zip

(My record is 51 sec)

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Physics coder

20

Years of Service

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Joined: 25th May 2004

Location: United States

Posted: 2nd Aug 2004 08:41

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cool although the camera isn't stable when it colides with the ground, it jitters, this might be fixed by using curvevalue or something to smooth the camera a bit. There might be something wrong with the moments of inertia for the towers, it seems like they don't fall over right. Still nice mini-game!

-----------------------------------
To delete the bug, delete the code.
Specs: Sony VAIO Laptop, Windows XP, P4 2.8Ghz, 512MB RAM, ATI Radeon 64MB video memory, DBP Upgrade 5.3.

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Mr Underhill

21

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Joined: 23rd Apr 2003

Location: The Forgotten Worlds...

Posted: 2nd Aug 2004 10:53

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yeah...great mini-game, but Physics Coder is right, the camera is very jittery. My record is 43 seconds, btw

!

Keep up the good work!

"You don't need a reason to help people."-Zidane (FFIX)
Jade Phoenix Software is on the way! Get ready for the rebirth of gaming!

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Juso

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Joined: 23rd Sep 2002

Location: Finland

Posted: 3rd Aug 2004 02:01

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Yeah camera shakes all the time, but it took only 3 hours to change about 20 lines of Physics coder's code to make this mini game.

My record is now 44 secs, so look out Mr Underhill.

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Code Snippets / smart camera following, uses Newton physics wrapper to avoid collision with walls