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Codger

21

Years of Service

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Joined: 23rd Nov 2002

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Posted: 15th Dec 2007 05:56 Edited at: 15th Dec 2007 05:58

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I modified the force field demo to to reverse the direction of the effect (repel instead of attack)

` create a stack of boxes

` start the physics simulation
`phy enable debug
phy start

` set the sync on and sync rate to 0 so we control the updating of the screen and it is
` drawn to as fast as possible
sync on
sync rate 60

` make background
load image "stripe5.png",1000
make object sphere 1000,400,48,48
texture object 1000,1000
scale object texture 1000,6,6
set object cull 1000,0
rotate object 1000,0,0,90

load image "stripe6.png", 3
make object box 1, 100, 1, 100
phy make rigid body static box 1
texture object 1, 3

ID = 10000

xpos# = -2
ypos# = 1
cubes = 5
for z = 0 to cubes
   for x = 0 to cubes
      for y = 0 to cubes

make object cube ID, 1

color object ID, rgb ( rnd ( 255 ), rnd ( 255 ), rnd ( 255 ) )
            set object specular ID, rgb ( rnd ( 255 ), rnd ( 255 ), rnd ( 255 ) )
            set object specular power ID, 255
            set object ambient ID, 0

position object ID, xpos#, ypos#, zpos#

phy make rigid body dynamic box ID

phy sleep rigid body ID

xpos# = xpos# + 1

inc ID

next y
      xpos# = -2
      ypos# = ypos# + 1
   next x
xpos# = -2
ypos# = 1
   zpos# = zpos# + 1
next z

` turn autocam off
autocam off

` position the camera so we can view the whole scene
`position camera 0.5, 2, -4

position camera 3, 10, -20

` create a light
make light 1
set directional light 1, -5,-5,5

a# = 0.0
b# = 0.0
c# = 0.0

` display Dark Physics logo
load image "logo.png", 100000
sprite 1, 0, 600 - 60, 100000

make object sphere 500, 2
position object 500, -10, 6, 0
phy make rigid body dynamic sphere 500
phy set rigid body kinematic 500, 1

phy create force field 1
phy set force field coordinates 1, 1
phy set force field constant 1, 800.0, 2000.0, 0.0
phy set force field rigid body 1, 500
phy build force field 1
phy add force field sphere 1, 0, 0.0, 0.0, 0.0, 4

fX# = -10
fY# = 6

do
   set cursor 0, 0
   print "Use the arrow keys to move the sphere press shift key to reverse force"

phy set rigid body kinematic position 500, fX#, fY#, 0

if upkey ( )
      fY# = fY# + 0.1
   endif

if downkey ( )
      fY# = fY# - 0.1
   endif

if leftkey ( )
      fX# = fX# - 0.1
   endif

if rightkey ( )
      fX# = fX# + 0.1
   endif

if shiftkey()
         phy set force field constant 1, 800.0, 2000.0, 0.0
   else
         phy set force field constant 1, -800.0, 2000.0, 0.0
   endif

` update the physics
   phy update

` now update the screen
   sync
loop

+ Code Snippet


` create a stack of boxes

` start the physics simulation
`phy enable debug
phy start

` set the sync on and sync rate to 0 so we control the updating of the screen and it is
` drawn to as fast as possible
sync on
sync rate 60

` make background
load image "stripe5.png",1000
make object sphere 1000,400,48,48
texture object 1000,1000
scale object texture 1000,6,6
set object cull 1000,0
rotate object 1000,0,0,90

load image "stripe6.png", 3
make object box 1, 100, 1, 100
phy make rigid body static box 1
texture object 1, 3


ID = 10000

xpos# = -2
ypos# = 1
cubes = 5
for z = 0 to cubes
   for x = 0 to cubes
      for y = 0 to cubes

            make object cube ID, 1

            color object ID, rgb ( rnd ( 255 ), rnd ( 255 ), rnd ( 255 ) )
            set object specular ID, rgb ( rnd ( 255 ), rnd ( 255 ), rnd ( 255 ) )
            set object specular power ID, 255
            set object ambient ID, 0

            position object ID, xpos#, ypos#, zpos#

            phy make rigid body dynamic box ID

            phy sleep rigid body ID

            xpos# = xpos# + 1

            inc ID

      next y
      xpos# = -2
      ypos# = ypos# + 1
   next x
xpos# = -2
ypos# = 1
   zpos# = zpos# + 1
next z



` turn autocam off
autocam off

` position the camera so we can view the whole scene
`position camera 0.5, 2, -4

position camera 3, 10, -20

` create a light
make light 1
set directional light 1, -5,-5,5


a# = 0.0
b# = 0.0
c# = 0.0

` display Dark Physics logo
load image "logo.png", 100000
sprite 1, 0, 600 - 60, 100000

make object sphere 500, 2
position object 500, -10, 6, 0
phy make rigid body dynamic sphere 500
phy set rigid body kinematic 500, 1

phy create force field 1
phy set force field coordinates 1, 1
phy set force field constant 1, 800.0, 2000.0, 0.0
phy set force field rigid body 1, 500
phy build force field 1
phy add force field sphere 1, 0, 0.0, 0.0, 0.0, 4


fX# = -10
fY# = 6

do
   set cursor 0, 0
   print "Use the arrow keys to move the sphere press shift key to reverse force"

   phy set rigid body kinematic position 500, fX#, fY#, 0

   if upkey ( )
      fY# = fY# + 0.1
   endif

   if downkey ( )
      fY# = fY# - 0.1
   endif

   if leftkey ( )
      fX# = fX# - 0.1
   endif

   if rightkey ( )
      fX# = fX# + 0.1
   endif

   if shiftkey()
         phy set force field constant 1, 800.0, 2000.0, 0.0
   else
         phy set force field constant 1, -800.0, 2000.0, 0.0
   endif

   ` update the physics
   phy update

   ` now update the screen
   sync
loop

when I tried to change the effect on the fly nothing happens

+ Code Snippet

   if shiftkey()
         phy set force field constant 1, 800.0, 2000.0, 0.0
   else
         phy set force field constant 1, -800.0, 2000.0, 0.0
   endif

am I doing something wrong

Codger

System
PIV 2.8 MZ 512 Mem
FX 5600 256 mem

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david w

18

Years of Service

User Offline

Joined: 18th Dec 2005

Location: U.S.A. Michigan

Posted: 15th Dec 2007 08:18

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I may be wrong here but it seems like to me that once its applied its a constant, cant be changed.

What I think you need to do is have 2 forces the opposite of each other then swap and sleep the one that is not active.

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Kendor

21

Years of Service

User Offline

Joined: 31st Jan 2003

Location: Malta

Posted: 15th Dec 2007 10:22 Edited at: 15th Dec 2007 10:23

Link

Yeah, it seems that you cannot change the parameters of a force field once it was created.

Option 1 is to delete the force field and create a new one on the fly:

+ Code Snippet

if returnkey() = 1 and rkey = 0 
	`delete old force 
		phy delete force field 1 
	
	`create new force
		phy create force field 1
		phy set force field coordinates 1, 1
		phy set force field constant 1, 800.0, 2000.0, 0.0
		phy set force field rigid body 1, 500
		phy build force field 1
		phy add force field sphere 1, 0, 0.0, 0.0, 0.0, 4
	rkey = 1
	endif

Option 2 and possibly a bug, is to not delete the force field but recreate it with enough force to counter act the previous one:

+ Code Snippet

	if returnkey() = 1 and rkey = 0 
		phy create force field 1
		phy set force field coordinates 1, 1
	`double the force to counter-act the previous one
		phy set force field constant 1, 1600.0, 2000.0, 0.0
		phy set force field rigid body 1, 500
		phy build force field 1
		phy add force field sphere 1, 0, 0.0, 0.0, 0.0, 4
	rkey = 1
	endif

It seems that it does not check whether a force field already exists and so does not report an error. The same applies to phy delete force field.

I think a better way to implement force fields would be similar to how materials are handled. You create a force field independent of the object and then apply it to the object/s when the need arises.

Theory is when you know something, but it doesn't work. Practice is when something works, but you don't know why.
Programmers combine theory and practice: Nothing works and they don't know why.

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Codger

21

Years of Service

User Offline

Joined: 23rd Nov 2002

Location:

Posted: 15th Dec 2007 20:48

Link

Once I delete the field "by pressing the mouse buttons" the effect disappears

` create a stack of boxes

` start the physics simulation
`phy enable debug
phy start

` set the sync on and sync rate to 0 so we control the updating of the screen and it is
` drawn to as fast as possible
sync on
sync rate 60

` make background
load image "stripe5.png",1000
make object sphere 1000,400,48,48
texture object 1000,1000
scale object texture 1000,6,6
set object cull 1000,0
rotate object 1000,0,0,90

load image "stripe6.png", 3
make object box 1, 100, 1, 100
phy make rigid body static box 1
texture object 1, 3

ID = 10000

xpos# = -2
ypos# = 1
cubes = 5
for z = 0 to cubes
   for x = 0 to cubes
      for y = 0 to cubes

make object cube ID, 1

color object ID, rgb ( rnd ( 255 ), rnd ( 255 ), rnd ( 255 ) )
            set object specular ID, rgb ( rnd ( 255 ), rnd ( 255 ), rnd ( 255 ) )
            set object specular power ID, 255
            set object ambient ID, 0

position object ID, xpos#, ypos#, zpos#

phy make rigid body dynamic box ID

phy sleep rigid body ID

xpos# = xpos# + 1

inc ID

next y
      xpos# = -2
      ypos# = ypos# + 1
   next x
xpos# = -2
ypos# = 1
   zpos# = zpos# + 1
next z

` turn autocam off
autocam off

` position the camera so we can view the whole scene
`position camera 0.5, 2, -4

position camera 3, 10, -20

` create a light
make light 1
set directional light 1, -5,-5,5

a# = 0.0
b# = 0.0
c# = 0.0

` display Dark Physics logo
load image "logo.png", 100000
sprite 1, 0, 600 - 60, 100000

make object sphere 500, 2
position object 500, -10, 6, 0
phy make rigid body dynamic sphere 500
phy set rigid body kinematic 500, 1

phy create force field 1
phy set force field coordinates 1, 1
phy set force field constant 1, 800.0, 2000.0, 0.0
phy set force field rigid body 1, 500
phy build force field 1
phy add force field sphere 1, 0, 0.0, 0.0, 0.0, 4

fX# = -10
fY# = 6

do
   set cursor 0, 0
   print "Use the arrow keys to move the sphere click left or right mouse to reverse force"

if upkey ( )
      fY# = fY# + 0.1
   endif

if downkey ( )
      fY# = fY# - 0.1
   endif

if leftkey ( )
      fX# = fX# - 0.1
   endif

if rightkey ( )
      fX# = fX# + 0.1
   endif

if mouseclick()= 1
      phy delete force field 1
      phy create force field 1
      phy set force field coordinates 1,1
      phy set force field constant 1, 1200.0, 2000.0, 0.0
      phy set force field rigid body 1, 500
      phy build force field 1
      phy add force field sphere 1, 0,fX#, fY#,0.0, 4
   endif
   if mouseclick()= 2
      phy delete force field 1
      phy create force field 1
      phy set force field coordinates 1,1
      phy set force field constant 1, -1200.0, -2000.0, 0.0
      phy set force field rigid body 1, 500
      phy build force field 1
      phy add force field sphere 1, 0, fX#, fY#,0.0, 4
   endif

phy set rigid body kinematic position 500, fX#, fY#, 0
   ` update the physics
   phy update

` now update the screen
   sync
loop

+ Code Snippet


` create a stack of boxes

` start the physics simulation
`phy enable debug
phy start

` set the sync on and sync rate to 0 so we control the updating of the screen and it is
` drawn to as fast as possible
sync on
sync rate 60

` make background
load image "stripe5.png",1000
make object sphere 1000,400,48,48
texture object 1000,1000
scale object texture 1000,6,6
set object cull 1000,0
rotate object 1000,0,0,90

load image "stripe6.png", 3
make object box 1, 100, 1, 100
phy make rigid body static box 1
texture object 1, 3


ID = 10000

xpos# = -2
ypos# = 1
cubes = 5
for z = 0 to cubes
   for x = 0 to cubes
      for y = 0 to cubes

            make object cube ID, 1

            color object ID, rgb ( rnd ( 255 ), rnd ( 255 ), rnd ( 255 ) )
            set object specular ID, rgb ( rnd ( 255 ), rnd ( 255 ), rnd ( 255 ) )
            set object specular power ID, 255
            set object ambient ID, 0

            position object ID, xpos#, ypos#, zpos#

            phy make rigid body dynamic box ID

            phy sleep rigid body ID

            xpos# = xpos# + 1

            inc ID

      next y
      xpos# = -2
      ypos# = ypos# + 1
   next x
xpos# = -2
ypos# = 1
   zpos# = zpos# + 1
next z



` turn autocam off
autocam off

` position the camera so we can view the whole scene
`position camera 0.5, 2, -4

position camera 3, 10, -20

` create a light
make light 1
set directional light 1, -5,-5,5


a# = 0.0
b# = 0.0
c# = 0.0

` display Dark Physics logo
load image "logo.png", 100000
sprite 1, 0, 600 - 60, 100000

make object sphere 500, 2
position object 500, -10, 6, 0
phy make rigid body dynamic sphere 500
phy set rigid body kinematic 500, 1

phy create force field 1
phy set force field coordinates 1, 1
phy set force field constant 1, 800.0, 2000.0, 0.0
phy set force field rigid body 1, 500
phy build force field 1
phy add force field sphere 1, 0, 0.0, 0.0, 0.0, 4


fX# = -10
fY# = 6

do
   set cursor 0, 0
   print "Use the arrow keys to move the sphere click left or right mouse to reverse force"



   if upkey ( )
      fY# = fY# + 0.1
   endif

   if downkey ( )
      fY# = fY# - 0.1
   endif

   if leftkey ( )
      fX# = fX# - 0.1
   endif

   if rightkey ( )
      fX# = fX# + 0.1
   endif

   if mouseclick()= 1
      phy delete force field 1
      phy create force field 1
      phy set force field coordinates 1,1
      phy set force field constant 1, 1200.0, 2000.0, 0.0
      phy set force field rigid body 1, 500
      phy build force field 1
      phy add force field sphere 1, 0,fX#, fY#,0.0, 4
   endif
   if mouseclick()= 2
      phy delete force field 1
      phy create force field 1
      phy set force field coordinates 1,1
      phy set force field constant 1, -1200.0, -2000.0, 0.0
      phy set force field rigid body 1, 500
      phy build force field 1
      phy add force field sphere 1, 0, fX#, fY#,0.0, 4
   endif

   phy set rigid body kinematic position 500, fX#, fY#, 0
   ` update the physics
   phy update

   ` now update the screen
   sync
loop

It will help when a more detailed explanation of the parameters are forhcoming

Codger

System
PIV 2.8 MZ 512 Mem
FX 5600 256 mem

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