Rotating when moving... - GameCreators Forum

Author

Message

Zotoaster

20

Years of Service

User Offline

Joined: 20th Dec 2004

Location: Scotland

Posted: 23rd Sep 2005 12:39 Edited at: 23rd Sep 2005 12:41

Link

I tried to pos this before, but then the thread turned into a convo about e-mails.. so I'll try again...

I can make my ball move around, and it slides around.. (I will post the code in a moment).. now, if you press the up key it will move along the z axis (for example). If you let go of the upkey, if will keep sliding in that direction, even if your facing another direction.. Now, what I want to do (and I need your help), it to make the ball always roll in the direction your going, not facing..

E.G.

if your moving along the z axis, and the ball if facing along the z axis, it shoul;d rotate round the X axis.
Say it keeps going in that direction, but you turn and face the X axis (moving along the z, facing x) the ball should then be x rotating....

I have no idea how to do this.. BUT, perhaps if I could get the angle between the direction im going, and direction im facing, maybe that would help, but I don't know...

Here's the imortant part of the code..

`Setup For Performance
Sync on
Sync rate 60
Hide mouse
set camera range 1,100000

`Create Game Elements
Gosub _Create_Elements

`--Main Loop--
Do

`Control Elements
Gosub _Control_Player

`--End Loop--
Sync
Loop

`---Subroutines---

_Create_Elements:

`Variables
fric#=0.95
speed#=3

`Arrays

`Player
make object sphere 1,100

Return

`Control PLayer
_Control_Player:

`Store old positions
oldx#=x#
oldy#=y#
oldz#=z#

`Check for keys pressed
if upkey()=1 then up=1 else up=0
if downkey()=1 then down=1 else down=0
if leftkey()=1 then left=1 else left=0
if rightkey()=1 then right=1 else right=0

`Physics
if up=1
xspeed#=xspeed#+newxvalue(0,ay#,speed#)
zspeed#=zspeed#+newzvalue(0,ay#,speed#)
endif
if left=1
ad#=wrapvalue(ad#-3.0)
endif
if right=1
ad#=wrapvalue(ad#+3.0)
endif
if up=1
last=1
endif
if down=1
last=2
endif
if up=0 and down=0 and last=1 then last=1
if up=0 and down=0 and last=2 then last=2
if last=1
move#=sqrt((oldx#-x#)^2+(oldy#-y#)^2+(oldz#-z#)^2)
endif
if last=2
move#=(sqrt((oldx#-x#)^2+(oldy#-y#)^2+(oldz#-z#)^2))*-1
endif
ay#=wrapvalue(curveangle(ad#,ay#,5.0))
xspeed#=xspeed#*fric#
zspeed#=zspeed#*fric#
x#=x#+xspeed#
z#=z#+zspeed#

`Update Player
position object 1,x#,y#,z#
yrotate object 1,ay#

`Tracking Camera
ca#=wrapvalue(curveangle(ay#,ca#,20.0))
cx#=newxvalue(x#,ca#,-600)
cz#=newzvalue(z#,ca#,-600)
cy#=curvevalue(y#+300,cy#,10.0)
position camera 0,cx#,cy#,cz#
yrotate camera 0,ca#
point camera 0,x#,y#,z#

`Return to Loop
Return

+ Code Snippet

`Setup For Performance
Sync on
Sync rate 60
Hide mouse
set camera range 1,100000

`Create Game Elements
Gosub _Create_Elements


`--Main Loop--
Do

`Control Elements
Gosub _Control_Player

`--End Loop--
Sync
Loop


`---Subroutines---

_Create_Elements:

`Variables
fric#=0.95
speed#=3

`Arrays

`Player
make object sphere 1,100

Return



`Control PLayer
_Control_Player:

`Store old positions
oldx#=x#
oldy#=y#
oldz#=z#

`Check for keys pressed
if upkey()=1 then up=1 else up=0
if downkey()=1 then down=1 else down=0
if leftkey()=1 then left=1 else left=0
if rightkey()=1 then right=1 else right=0

`Physics
if up=1
xspeed#=xspeed#+newxvalue(0,ay#,speed#)
zspeed#=zspeed#+newzvalue(0,ay#,speed#)
endif
if left=1
ad#=wrapvalue(ad#-3.0)
endif
if right=1
ad#=wrapvalue(ad#+3.0)
endif
if up=1
last=1
endif
if down=1
last=2
endif
if up=0 and down=0 and last=1 then last=1
if up=0 and down=0 and last=2 then last=2
if last=1
move#=sqrt((oldx#-x#)^2+(oldy#-y#)^2+(oldz#-z#)^2)
endif
if last=2
move#=(sqrt((oldx#-x#)^2+(oldy#-y#)^2+(oldz#-z#)^2))*-1
endif
ay#=wrapvalue(curveangle(ad#,ay#,5.0))
xspeed#=xspeed#*fric#
zspeed#=zspeed#*fric#
x#=x#+xspeed#
z#=z#+zspeed#

`Update Player
position object 1,x#,y#,z#
yrotate object 1,ay#

`Tracking Camera
ca#=wrapvalue(curveangle(ay#,ca#,20.0))
cx#=newxvalue(x#,ca#,-600)
cz#=newzvalue(z#,ca#,-600)
cy#=curvevalue(y#+300,cy#,10.0)
position camera 0,cx#,cy#,cz#
yrotate camera 0,ca#
point camera 0,x#,y#,z#

`Return to Loop
Return

And a bit of code to find out how fast you're going to determine the speed to roll (already in the main part of the code)

+ Code Snippet

move#=sqrt((oldx#-x#)^2+(oldy#-y#)^2+(oldz#-z#)^2)

Thanks to all those you can help (and I guess those who try)

Back to top

Profile PM Email

TDK

Retired Moderator

22

Years of Service

User Offline

Joined: 19th Nov 2002

Location: UK

Posted: 23rd Sep 2005 17:11 Edited at: 23rd Sep 2005 17:14

Link

Hmmm... I love a challenge - and I'd never tried this before.

The trick is to calculate the amount of movement for the ball along the X and Z axis. This way, the actual position of the ball is independent of the ball's rotation.

Rather than calculate this real-time every time you rotate the object on the Y axis, (which would be slow), a procedure at the start of the program pre-calculates all the values for each of the 360 degrees of rotation and places them in arrays. This is done in CalcDirection.

You can then alter the ball's position using these arrays with the current Y angle of the ball as the array's index.

By rotating the ball on one angle - increasing for forwards and decreasing for backwards, all you need to do is make sure that the camera is behind the ball at all times. This is done with Set Camera To Follow.

Job done - but definitely a tricky one!

Nice challenge.

Dim DirX#(359)
Dim DirZ#(359)
Sync On
Sync Rate 60
Make Matrix 1,5000,5000,30,30

Ballx#=2500
Bally#=0
Ballz#=2500

Load object "Ball.x",1
YRotate Object 1,91
SET OBJECT ROTATION ZYX 1
position object 1,Ballx#,Bally#,Ballz#
Gosub CalcDirection: Rem Direction Percentage For All Object Angles

do
  if rightkey()=1
    YRotate Object 1,WrapValue(Object Angle Y(1)+1)
    ObAngX# = DirX#(Object Angle Y(1))
    ObAngZ# = DirZ#(Object Angle Y(1))
  Endif
  if leftkey()=1
    YRotate Object 1,WrapValue(Object Angle Y(1)-1)
    ObAngX# = DirX#(Object Angle Y(1))
    ObAngZ# = DirZ#(Object Angle Y(1))
  Endif
  if upkey()=1
    Inc Ballx#,DirX#(Object Angle Y(1))*2
    Inc Ballz#,DirZ#(Object Angle Y(1))*2
    Position Object 1,Ballx#,Bally#,Ballz#
    XRotate Object 1,WrapValue(Object Angle X(1)+5)
  Endif
  if downkey()=1
    Dec Ballx#,DirX#(Object Angle Y(1))*2
    Dec Ballz#,DirZ#(Object Angle Y(1))*2
    Position Object 1,Ballx#,Bally#,Ballz#
    XRotate Object 1,WrapValue(Object Angle X(1)-5)
  Endif
  Set Camera To Follow Object Position X(1),Object Position Y(1),Object Position Z(1),Object Angle Y(1),50,20,1,0
  Sync
loop

CalcDirection:
  Rem This procedure pre-calculates all the amounts to increment the X and Z positions of an object for
  Rem each of the 360 possible angles you can rotate it on the Y axis.
  For Angle = 0 To 359
    If Angle = 0
      Rem Up
      DirX#(Angle) = 0.0
      DirZ#(Angle) = 90.0
    Endif
    If ANGLE = 90
      Rem Right   270
      DirX#(Angle) = 360.0-ANGLE 
      DirZ#(Angle) = 0.0
    Endif
    If ANGLE = 180
      Rem Down
      DirX#(Angle) = 0.0
      DirZ#(Angle) = 0 - (ANGLE-90.0)
    Endif
    If ANGLE = 270
      Rem left   90
      DirX#(Angle) = 0-90.0
      DirZ#(Angle) = 0.0
    Endif
    If ANGLE > 0 and ANGLE < 90
      Rem up right   1 to 89
      DirX#(Angle) = ANGLE
      DirZ#(Angle) = 90.0 - ANGLE
    Endif
    If ANGLE > 270 and ANGLE < 360
      Rem Up left 271 to 359
      DirX#(Angle) = ANGLE - 360.0
      DirZ#(Angle) = 90.0-(360.0 - ANGLE)
    Endif
    If ANGLE > 90 and ANGLE < 180
      Rem Down right - 91 to 179
      DirX#(Angle) = (180.0 - ANGLE)
      DirZ#(Angle) = 0 - (ANGLE - 90.0)
    Endif
    If ANGLE > 180 and ANGLE < 270
      Rem Down left  181 - 269
      DirX#(Angle) = 180.0 - ANGLE
      DirZ#(Angle) = 0 - (270.0-ANGLE)
    Endif
    DirX#(Angle) = DirX#(Angle)/100
    DirZ#(Angle) = DirZ#(Angle)/100
  Next Angle
Return

+ Code Snippet

Dim DirX#(359)
Dim DirZ#(359)
Sync On
Sync Rate 60
Make Matrix 1,5000,5000,30,30

Ballx#=2500
Bally#=0
Ballz#=2500

Load object "Ball.x",1
YRotate Object 1,91
SET OBJECT ROTATION ZYX 1
position object 1,Ballx#,Bally#,Ballz#
Gosub CalcDirection: Rem Direction Percentage For All Object Angles

do
  if rightkey()=1
    YRotate Object 1,WrapValue(Object Angle Y(1)+1)
    ObAngX# = DirX#(Object Angle Y(1))
    ObAngZ# = DirZ#(Object Angle Y(1))
  Endif
  if leftkey()=1
    YRotate Object 1,WrapValue(Object Angle Y(1)-1)
    ObAngX# = DirX#(Object Angle Y(1))
    ObAngZ# = DirZ#(Object Angle Y(1))
  Endif
  if upkey()=1
    Inc Ballx#,DirX#(Object Angle Y(1))*2
    Inc Ballz#,DirZ#(Object Angle Y(1))*2
    Position Object 1,Ballx#,Bally#,Ballz#
    XRotate Object 1,WrapValue(Object Angle X(1)+5)
  Endif
  if downkey()=1
    Dec Ballx#,DirX#(Object Angle Y(1))*2
    Dec Ballz#,DirZ#(Object Angle Y(1))*2
    Position Object 1,Ballx#,Bally#,Ballz#
    XRotate Object 1,WrapValue(Object Angle X(1)-5)
  Endif
  Set Camera To Follow Object Position X(1),Object Position Y(1),Object Position Z(1),Object Angle Y(1),50,20,1,0
  Sync
loop


CalcDirection:
  Rem This procedure pre-calculates all the amounts to increment the X and Z positions of an object for
  Rem each of the 360 possible angles you can rotate it on the Y axis.
  For Angle = 0 To 359
    If Angle = 0
      Rem Up
      DirX#(Angle) = 0.0
      DirZ#(Angle) = 90.0
    Endif
    If ANGLE = 90
      Rem Right   270
      DirX#(Angle) = 360.0-ANGLE 
      DirZ#(Angle) = 0.0
    Endif
    If ANGLE = 180
      Rem Down
      DirX#(Angle) = 0.0
      DirZ#(Angle) = 0 - (ANGLE-90.0)
    Endif
    If ANGLE = 270
      Rem left   90
      DirX#(Angle) = 0-90.0
      DirZ#(Angle) = 0.0
    Endif
    If ANGLE > 0 and ANGLE < 90
      Rem up right   1 to 89
      DirX#(Angle) = ANGLE
      DirZ#(Angle) = 90.0 - ANGLE
    Endif
    If ANGLE > 270 and ANGLE < 360
      Rem Up left 271 to 359
      DirX#(Angle) = ANGLE - 360.0
      DirZ#(Angle) = 90.0-(360.0 - ANGLE)
    Endif
    If ANGLE > 90 and ANGLE < 180
      Rem Down right - 91 to 179
      DirX#(Angle) = (180.0 - ANGLE)
      DirZ#(Angle) = 0 - (ANGLE - 90.0)
    Endif
    If ANGLE > 180 and ANGLE < 270
      Rem Down left  181 - 269
      DirX#(Angle) = 180.0 - ANGLE
      DirZ#(Angle) = 0 - (270.0-ANGLE)
    Endif
    DirX#(Angle) = DirX#(Angle)/100
    DirZ#(Angle) = DirZ#(Angle)/100
  Next Angle
Return

A New Alternative IDE For DB Classic!

Back to top

Profile PM Email Website

Zotoaster

20

Years of Service

User Offline

Joined: 20th Dec 2004

Location: Scotland

Posted: 23rd Sep 2005 17:19

Link

this looks good, but it doesn't really help.. my ball slides around, and the problem is that i wanted to spin in the direction that its going, even if you turn the ball...

Back to top

Profile PM Email

TDK

Retired Moderator

22

Years of Service

User Offline

Joined: 19th Nov 2002

Location: UK

Posted: 23rd Sep 2005 17:26

Link

That's what it does.

TDK_Man

A New Alternative IDE For DB Classic!

Back to top

Profile PM Email Website

Zotoaster

20

Years of Service

User Offline

Joined: 20th Dec 2004

Location: Scotland

Posted: 23rd Sep 2005 17:50

Link

not really.. cos whenm you move you dont keep liding the way you do in my code, which means that if you turn to the side you go in the direction your facing, not the way you were going earlier

Back to top

Profile PM Email

Leeorg

19

Years of Service

User Offline

Joined: 5th Jul 2005

Location:

Posted: 23rd Sep 2005 20:14

Link

Are you saying that the ball stays travelling in any said direction but camera can swivel round the ball? so you are facing another direction but not going in that direction?

Back to top

Profile PM Email

Zotoaster

20

Years of Service

User Offline

Joined: 20th Dec 2004

Location: Scotland

Posted: 23rd Sep 2005 22:06

Link

you can move, and it moves in that direction no matter which way you face.. but eventually the ball slows down. tyr the source code

Back to top

Profile PM Email

TDK

Retired Moderator

22

Years of Service

User Offline

Joined: 19th Nov 2002

Location: UK

Posted: 24th Sep 2005 01:04

Link

I didn't realise you'd posted working code - when you said:

Quote: "Here's the imortant part of the code.."

... I assumed it was only a section of the main program just for us to look at, so I didn't even try running it.

It wouldn't have mattered anyway - I just tried it and the code is DBP and doesn't run in classic. I tried it in DBP too but it didn't seem to be working in that either.

All I get is a white sphere on an empty blue backdrop. The sphere seems to rotate but doesn't do anything else.

TDK_Man

A New Alternative IDE For DB Classic!

Back to top

Profile PM Email Website

Zotoaster

20

Years of Service

User Offline

Joined: 20th Dec 2004

Location: Scotland

Posted: 24th Sep 2005 03:23

Link

aha, yeah. Just make a simple matrix so you can see yourself moving.. lol, and to make it work on dbc just take away the camera number

Back to top

Profile PM Email

Uncle Sam

19

Years of Service

User Offline

Joined: 23rd Jul 2005

Location: West Coast, USA

Posted: 24th Sep 2005 10:22

Link

I'm making basically the same thing meself.

Here's how:

+ Code Snippet

rem swivel camera with mouse
angley#=curveangle(angley#+mousemovex(),angley#,5)
yrotate camera angley#

rem code for direction
obja#=object angle y(object number of ball object)
if upkey()=1
  x#=newvalue(x#,obja#,10)
  z#=newvalue(x#,obja#,10)
endif
if downkey()=1
  x#=newvalue(x#,obja#-180,5)
  z#=newvalue(x#,obja#-180,5)
endif
if leftkey()=1
  obja#=wrapvalue(obja#-3)
endif
if rightkey()=1
  obja#=wrapvalue(obja#+3)
endif
y#=get ground height(matrix number,x#,z#)
yrotate object object numner of your ball object,obja#
position object object numner of your ball object,x#,y#,z#

Hope that's what you wanted.

--------------
Uncle Sam

Back to top

Profile PM Email

Zotoaster

20

Years of Service

User Offline

Joined: 20th Dec 2004

Location: Scotland

Posted: 24th Sep 2005 14:50

Link

well it rolls around, but if you turn to the side, thats the way you go, its different with mine..

Back to top

Profile PM Email

SimSmall

20

Years of Service

User Offline

Joined: 7th Aug 2004

Location: United Kingdom

Posted: 25th Sep 2005 00:57

Link

So you're after like an effect of a car (or in this case: ball) skidding - rather than just turning and moving perfectly in its new direction?

Well, I personally don't know how to do that, but perhaps others might (if that's even what you're after at all...)

...maybe one day I'll finish a project

Back to top

Profile PM Email

Zotoaster

20

Years of Service

User Offline

Joined: 20th Dec 2004

Location: Scotland

Posted: 25th Sep 2005 02:06

Link

No nonononono! I dont think anyone understands

Ok: have you ever went bowling? Well, say you drew a face on the bowling ball, and rolled it so its face would hit off the ground, it would rotate round the X axis.. but, turn it so the face is facing the arcade-section, it spins rounds its Z axis..

ok, so, say the bowling ball had a mind of its own.. it went towards the pins, but it didn't want to, it wanted to go into the gutter (which is what normally happens

), it will turn to face the side, but kepp rolling in the direction its going - towards the pins.. - now, say it starts to move forward.. it will move slightly on the x axis, and slightly on the Z axis.. so - which way does it roll? mostly round the X axis, and a little on the Z axis.. the faster it moves towards the gutter the faster it spins round the z axis (NOT the balls z axis)

This is what the ball does so far then -- moves fast towards the pins, and slowly towards the gutter.. how will it spin? - Alot round the Z axis (cos thats mainly the direction its going), and a little rouind the X axis. (cos thats also the way its going, just not as fast)

BUT, if the ball moves faster towards the gutter than it does the pins, then it will spin faster round its X axis rather than the Z axis - but it will still spin round the z axis a little 'cause its moving slightly in that direction

THIS is what I want to achieve, I hope I gave enough detail

thanks again

Back to top

Profile PM Email

Sorry your browser is not supported!

DarkBASIC Discussion / Rotating when moving...