[dark physics] phy set rigid body rotation bug on Y axis

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Trowbee

21

Years of Service

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Joined: 12th Apr 2003

Location: United Kingdom

Posted: 16th Feb 2007 05:19 Edited at: 16th Feb 2007 20:17

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Using the latest version, and beta download, phy set rigid body rotation on the y axis does not work as expected.

X and Z work fine (although not in tandem, unless I'm using the command incorrectly).

However, along the Y axis, not only does it not rotate past -180 and +180, it doesn't always even rotate in the right direction!

sync on : sync rate 60

Make object Cube 1,5
phy start
phy set gravity 0,0,0
Phy Make rigid body dynamic box 1

KEY_UP=200 : KEY_DOWN=208 : KEY_LEFT=203 : KEY_RIGHT=205 : KEY_RIGHTCONTROL=157 : KEY_NUMZERO=82 : KEY_SPACE=57

Do

if keystate(KEY_UP)=1 Then phy set rigid body rotation 1, wrapvalue(object angle x(1)+5), object angle y(1), object angle z(1)
   if keystate(KEY_DOWN)=1 Then phy set rigid body rotation 1, wrapvalue(object angle x(1)-5), object angle y(1), object angle z(1)
   if keystate(KEY_LEFT)=1 Then phy set rigid body rotation 1, object angle x(1), wrapvalue(object angle y(1)-5), object angle z(1)
   if keystate(KEY_RIGHT)=1 Then phy set rigid body rotation 1, object angle x(1), wrapvalue(object angle y(1)+5), object angle z(1)

if keystate(KEY_RIGHTCONTROL)=1 Then phy set rigid body rotation 1, object angle x(1), object angle y(1), wrapvalue(object angle z(1)+5)
   if keystate(KEY_NUMZERO)=1 Then phy set rigid body rotation 1, object angle x(1), object angle y(1), wrapvalue(object angle z(1)-5)

if keystate(KEY_SPACE)=1 then phy set rigid body rotation 1,0,0,0

text 0,0,"X = "+str$(object angle x(1))
   text 0,20,"Y = "+str$(object angle y(1))
   text 0,40,"Z = "+str$(object angle z(1))

phy update
sync
Loop

+ Code Snippet

sync on : sync rate 60

Make object Cube 1,5
phy start
phy set gravity 0,0,0
Phy Make rigid body dynamic box 1

KEY_UP=200 : KEY_DOWN=208 : KEY_LEFT=203 : KEY_RIGHT=205 : KEY_RIGHTCONTROL=157 : KEY_NUMZERO=82 : KEY_SPACE=57

Do

   if keystate(KEY_UP)=1 Then phy set rigid body rotation 1, wrapvalue(object angle x(1)+5), object angle y(1), object angle z(1)
   if keystate(KEY_DOWN)=1 Then phy set rigid body rotation 1, wrapvalue(object angle x(1)-5), object angle y(1), object angle z(1)
   if keystate(KEY_LEFT)=1 Then phy set rigid body rotation 1, object angle x(1), wrapvalue(object angle y(1)-5), object angle z(1)
   if keystate(KEY_RIGHT)=1 Then phy set rigid body rotation 1, object angle x(1), wrapvalue(object angle y(1)+5), object angle z(1)

   if keystate(KEY_RIGHTCONTROL)=1 Then phy set rigid body rotation 1, object angle x(1), object angle y(1), wrapvalue(object angle z(1)+5)
   if keystate(KEY_NUMZERO)=1 Then phy set rigid body rotation 1, object angle x(1), object angle y(1), wrapvalue(object angle z(1)-5)

   if keystate(KEY_SPACE)=1 then phy set rigid body rotation 1,0,0,0

   text 0,0,"X = "+str$(object angle x(1))
   text 0,20,"Y = "+str$(object angle y(1))
   text 0,40,"Z = "+str$(object angle z(1))

   phy update
sync
Loop

EDIT:
So, the object not rotating along multiple dimensions at the same time is fixed when its one call over the multiple calls details above - and added a comparative object too.

Updated code to reflect this is:

sync on : sync rate 60

Make object Cube 1,5
Make object Cube 2,5

position object 1,-5,0,0
position object 2,5,0,0

position camera 0,0,-20
point camera 0,0,0

phy start
phy set gravity 0,0,0
Phy Make rigid body dynamic box 1

KEY_UP=200 : KEY_DOWN=208 : KEY_LEFT=203 : KEY_RIGHT=205 : KEY_RIGHTCONTROL=157 : KEY_NUMZERO=82 : KEY_SPACE=57

Do

xshift = (keystate(KEY_UP)-keystate(KEY_DOWN))*5
   yshift = (keystate(KEY_LEFT)-keystate(KEY_RIGHT))*5
   zshift = (keystate(KEY_RIGHTCONTROL)-keystate(KEY_NUMZERO))*5

phy set rigid body rotation 1,wrapvalue(object angle x(1)+xshift),wrapvalue(object angle y(1)+yshift),wrapvalue(object angle z(1)+zshift)
   rotate object 2,wrapvalue(object angle x(2)+xshift),wrapvalue(object angle y(2)+yshift),wrapvalue(object angle z(2)+zshift)

if keystate(KEY_SPACE)=1
      phy set rigid body rotation 1,0,0,0
      rotate object 2,0,0,0
   endif

if (object angle x(1)<0 OR object angle x(1)<>object angle x(1)) : ink rgb(255,0,0),0 : else : ink rgb(255,255,255),0 : endif
   text object screen x(1)-30,100,"X = "+str$(object angle x(1))
   if (object angle y(1)<0 OR object angle y(1)<>object angle y(1)) : ink rgb(255,0,0),0 : else : ink rgb(255,255,255),0 : endif
   text object screen x(1)-30,120,"Y = "+str$(object angle y(1))
   if (object angle z(1)<0 OR object angle z(1)<>object angle z(1)) : ink rgb(255,0,0),0 : else : ink rgb(255,255,255),0 : endif
   text object screen x(1)-30,140,"Z = "+str$(object angle z(1))

ink rgb(255,255,255),0
   text object screen x(2)-30,100,"X = "+str$(object angle x(2))
   text object screen x(2)-30,120,"Y = "+str$(object angle y(2))
   text object screen x(2)-30,140,"Z = "+str$(object angle z(2))

text 0,0,"UP/DOWN = xrotate"
   text 0,20,"LEFT/RIGHT = yrotate"
   text 0,40,"CTRL/NUM ZERO = zrotate"
   text 0,60,"SPACE = reset"

phy update
sync
Loop

+ Code Snippet

sync on : sync rate 60

Make object Cube 1,5
Make object Cube 2,5

position object 1,-5,0,0
position object 2,5,0,0

position camera 0,0,-20
point camera 0,0,0

phy start
phy set gravity 0,0,0
Phy Make rigid body dynamic box 1


KEY_UP=200 : KEY_DOWN=208 : KEY_LEFT=203 : KEY_RIGHT=205 : KEY_RIGHTCONTROL=157 : KEY_NUMZERO=82 : KEY_SPACE=57

Do

   xshift = (keystate(KEY_UP)-keystate(KEY_DOWN))*5
   yshift = (keystate(KEY_LEFT)-keystate(KEY_RIGHT))*5
   zshift = (keystate(KEY_RIGHTCONTROL)-keystate(KEY_NUMZERO))*5

   phy set rigid body rotation 1,wrapvalue(object angle x(1)+xshift),wrapvalue(object angle y(1)+yshift),wrapvalue(object angle z(1)+zshift)
   rotate object 2,wrapvalue(object angle x(2)+xshift),wrapvalue(object angle y(2)+yshift),wrapvalue(object angle z(2)+zshift)


   if keystate(KEY_SPACE)=1
      phy set rigid body rotation 1,0,0,0
      rotate object 2,0,0,0
   endif

   if (object angle x(1)<0 OR object angle x(1)<>object angle x(1)) : ink rgb(255,0,0),0 : else : ink rgb(255,255,255),0 : endif
   text object screen x(1)-30,100,"X = "+str$(object angle x(1))
   if (object angle y(1)<0 OR object angle y(1)<>object angle y(1)) : ink rgb(255,0,0),0 : else : ink rgb(255,255,255),0 : endif
   text object screen x(1)-30,120,"Y = "+str$(object angle y(1))
   if (object angle z(1)<0 OR object angle z(1)<>object angle z(1)) : ink rgb(255,0,0),0 : else : ink rgb(255,255,255),0 : endif
   text object screen x(1)-30,140,"Z = "+str$(object angle z(1))

   ink rgb(255,255,255),0
   text object screen x(2)-30,100,"X = "+str$(object angle x(2))
   text object screen x(2)-30,120,"Y = "+str$(object angle y(2))
   text object screen x(2)-30,140,"Z = "+str$(object angle z(2))

   text 0,0,"UP/DOWN = xrotate"
   text 0,20,"LEFT/RIGHT = yrotate"
   text 0,40,"CTRL/NUM ZERO = zrotate"
   text 0,60,"SPACE = reset"


   phy update
sync
Loop

But even so, the object encounters gimbal lock that easily? On a *virtual* object, it won't under the same conditions.

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Philip

20

Years of Service

User Offline

Joined: 15th Jun 2003

Location: United Kingdom

Posted: 18th Mar 2007 16:44

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I'm a little sceptical that there is a bug with this command. I think maybe you are getting a bit confused because of gimbal lock etc.

I say that because the command seems to work 100% correctly in conjunction with WOLF's EZrotate commands. Here is an example of using the left and right keys to rotate a rigid body around its local Y axis. You'll need to use the downkey to rotate the object away from being orthagonal to the worldspace axes in order to see what I mean. Also, if you don't have a PPU (like lucky old me), you'll need to adjust the phy start command's arguments.

phy start 1, 0, 1
autocam off
sync on
sync rate 60
color backdrop 0
position camera 0, 20, -100

phy set gravity 0, 0, 0

` a cube is created and positioned on top of the floor over to the left
make object cube 2, 10
position object 2, 0, 10, 0
color object 2, rgb(255, 0, 0)
set object light 2, 1
set object ambient 2, 1
phy make rigid body dynamic box 2
phy set rigid body gravity 2, 0

position camera 0, 180, 0
rotate camera 90, 0, 0

` now we get to our main program loop
repeat
   set cursor 0, 0
   print "Demonstration of controlling rigid bodies movement"
   print "Move the rigid body box around with the arrow keys"

` turn left
   if leftkey ( ) = 1
   	
   	EZro_SetEuler OBJECT ANGLE X(2), OBJECT ANGLE Y(2), OBJECT ANGLE Z(2)
     EZro_SetPos OBJECT POSITION X(2),OBJECT POSITION Y(2),OBJECT POSITION Z(2)
	EZro_lY -1
   	EZro_FindEuler
   	phy set rigid body rotation 2, ezro_geteulerx(), ezro_geteulery(), ezro_geteulerz()
   
   endif

` turn right
   if rightkey ( ) = 1
      
	EZro_SetEuler OBJECT ANGLE X(2), OBJECT ANGLE Y(2), OBJECT ANGLE Z(2)
     EZro_SetPos OBJECT POSITION X(2), OBJECT POSITION Y(2), OBJECT POSITION Z(2)
     EZro_lY 1
   	EZro_FindEuler
   	phy set rigid body rotation 2, ezro_geteulerx(), ezro_geteulery(), ezro_geteulerz()

endif

` apply force
   if upkey ( ) = 1
      
      phy add rigid body local force 2, 1000, 0, 0, 5
   
   endif

if downkey() > 0
		
		phy set rigid body angular velocity 2, 1, 0, 1
		
	endif

` stop linear momentum
   phy set rigid body linear momentum 2, 0.0, 0.0, 0.0

` now we update the physics simulation and the screen
   phy update

` reset angular velocity
   phy set rigid body angular velocity 2, 0.0, 0.0, 0.0

sync
until spacekey() > 0

flush video memory
end

+ Code Snippet

phy start 1, 0, 1
autocam off
sync on
sync rate 60
color backdrop 0
position camera 0, 20, -100

phy set gravity 0, 0, 0 


` a cube is created and positioned on top of the floor over to the left
make object cube 2, 10
position object 2, 0, 10, 0
color object 2, rgb(255, 0, 0)
set object light 2, 1
set object ambient 2, 1
phy make rigid body dynamic box 2
phy set rigid body gravity 2, 0



position camera 0, 180, 0
rotate camera 90, 0, 0

` now we get to our main program loop
repeat
   set cursor 0, 0
   print "Demonstration of controlling rigid bodies movement"
   print "Move the rigid body box around with the arrow keys"

   ` turn left
   if leftkey ( ) = 1
   	
   	EZro_SetEuler OBJECT ANGLE X(2), OBJECT ANGLE Y(2), OBJECT ANGLE Z(2)
     EZro_SetPos OBJECT POSITION X(2),OBJECT POSITION Y(2),OBJECT POSITION Z(2)
	EZro_lY -1
   	EZro_FindEuler
   	phy set rigid body rotation 2, ezro_geteulerx(), ezro_geteulery(), ezro_geteulerz()
   
   endif

   ` turn right
   if rightkey ( ) = 1
      
	EZro_SetEuler OBJECT ANGLE X(2), OBJECT ANGLE Y(2), OBJECT ANGLE Z(2)
     EZro_SetPos OBJECT POSITION X(2), OBJECT POSITION Y(2), OBJECT POSITION Z(2)
     EZro_lY 1
   	EZro_FindEuler
   	phy set rigid body rotation 2, ezro_geteulerx(), ezro_geteulery(), ezro_geteulerz()

   endif

   ` apply force
   if upkey ( ) = 1
      
      phy add rigid body local force 2, 1000, 0, 0, 5
   
   endif

	if downkey() > 0
		
		phy set rigid body angular velocity 2, 1, 0, 1
		
	endif

   ` stop linear momentum
   phy set rigid body linear momentum 2, 0.0, 0.0, 0.0

   ` now we update the physics simulation and the screen
   phy update

   ` reset angular velocity
   phy set rigid body angular velocity 2, 0.0, 0.0, 0.0

   sync
until spacekey() > 0

flush video memory
end

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Bug Reports / [dark physics] phy set rigid body rotation bug on Y axis