example of SetObjectRotationQuat

Author

Message

basjak

14

Years of Service

User Offline

Joined: 16th Apr 2010

Location: feel like signing up for mars

Posted: 17th May 2013 01:12 Edited at: 17th May 2013 01:23

Link

am trying to make rotation using euler (no problem at all) and quaternion (problem)

did anyone work on it? please correct my example:

(am ok in term of understanding the quaternion mathematic but it seems am not managing to apply it in here.)

+ Code Snippet

setdisplayaspect(320/480.0)
setvirtualresolution(320,480)

createlightdirectional(1,0,-20,1000,255,255,255)


loadimage(1,"kkk.png")

CreateObjectcone( 1, 3,3,3 )
setobjectcolor(1,0,125,0,255)
SetObjectposition( 1,3,0,0 )
`rotateobjectlocalx(1,45)

CreateObjectcone( 2, 3,3,3 )
setobjectcolor(2,0,125,0,255)
SetObjectposition( 2,-3,0,0 )
`rotateobjectlocalx(2,45)

do
   if getpointerstate()
   y#=y#+1
   SetObjectRotation( 1, 45, y#, 0 )
   SetObjectRotationQuat( 2, w#,x#,y#,z# )  ` don't know what to do with it.
   endif
    sync()
loop

Back to top

Profile PM Email Website

basjak

14

Years of Service

User Offline

Joined: 16th Apr 2010

Location: feel like signing up for mars

Posted: 17th May 2013 01:22 Edited at: 17th May 2013 01:24

Link

--
sorry the message seemed to be posted twice so I deleted this one.

Back to top

Profile PM Email Website

Markus

Valued Member

20

Years of Service

User Offline

Joined: 10th Apr 2004

Location: Germany

Posted: 17th May 2013 13:38 Edited at: 17th May 2013 13:40

Link

SetObjectRotation is ok for a start angle at all axis but there is a axis order. one axis can affect a other.

its better you rotate relativ and not absolute.
RotateObjectLocalX
RotateObjectLocalY
RotateObjectLocalZ
RotateObjectGlobalX
RotateObjectGlobalY
RotateObjectGlobalZ

Quaternion i can't explain
http://en.wikipedia.org/wiki/Quaternion

a little bit you can read in help file, F1 over command SetObjectRotationQuat

Back to top

Profile PM Email

Van B

Moderator

22

Years of Service

User Offline

Joined: 8th Oct 2002

Location: Sunnyvale

Posted: 17th May 2013 14:21

Link

One good example might be a rolling ball, like a pool ball for example. You might use the local rotation to set it as random, like a random orientation - but then use the global rotation on X and Z depending on the objects movement, to replicate the ball rolling around a table. I've actually made a pool table simulation using 3D pool balls controlled via sprites with Box2D, works remarkably well - just a shame that Box2D doesn't really cut it for a pool game (at least as far as I can tell).

The local rotations affect the object locally, so if you rotate an object locally on 2 or more axis, it can be difficult to predict the results, especially if Z rotation comes into play. Local rotation is good when you only need to rotate one axis, like turning a turret, you'd rotate on the Y axis - but if you needed to rotate the turret up and down, rotating on the X axis globally would work - but rotating on the X axis locally would probably not.

I got a fever, and the only prescription, is more memes.

Back to top

Profile PM Email

basjak

14

Years of Service

User Offline

Joined: 16th Apr 2010

Location: feel like signing up for mars

Posted: 17th May 2013 14:30

Link

thanks guys, I don't have a problem with local and global rotation.

the Quaternion system is better in solving real life cases where we need to make a smooth rotation from one point to another. however, it seems that am unable to apply it here.

Back to top

Profile PM Email Website

Brendy boy

19

Years of Service

User Offline

Joined: 17th Jul 2005

Location: Croatia

Posted: 18th May 2013 02:42 Edited at: 18th May 2013 02:43

Link

x#,y#,z# are directions of a rotation axis and w# is amount of rotation around that axis

For example:
-you want to rotate an object around y axis for 33 degrees:
x#=0, y#=1, z#=0, w#=33

BBB GUI Plugin
Landscape & Map Creator

Back to top

Profile PM Email

basjak

14

Years of Service

User Offline

Joined: 16th Apr 2010

Location: feel like signing up for mars

Posted: 19th May 2013 15:28

Link

still not working:

+ Code Snippet

setdisplayaspect(320/480.0)
setvirtualresolution(320,480)
setclearcolor(0,0,125)

createlightdirectional(1,0,-20,1000,255,255,255)

CreateObjectcone( 1, 3,3,3 )
setobjectcolor(1,125,125,0,255)
SetObjectposition( 1,3,0,0 )


do
   if getpointerstate()
   y#=y#+3
    SetObjectRotationQuat( 1, y#,0,1,0 )
   endif
    sync()
loop

Back to top

Profile PM Email Website

Brendy boy

19

Years of Service

User Offline

Joined: 17th Jul 2005

Location: Croatia

Posted: 19th May 2013 21:40

Link

are you sure that parameters are in that order - w#,x#,y#,z#?
I don't have AppGameKit so i can't check but maybe they're in different order - have you tried x#,y#,z#,w#?

BBB GUI Plugin
Landscape & Map Creator

Back to top

Profile PM Email

basjak

14

Years of Service

User Offline

Joined: 16th Apr 2010

Location: feel like signing up for mars

Posted: 19th May 2013 22:26

Link

yep the parameters are w#,x#,y#,z#. I already tried x#,y#,z#,w# as I thought there could be something wrong but didn't work.

Back to top

Profile PM Email Website

lilpissywilly

AGK Developer

14

Years of Service

User Offline

Joined: 10th Sep 2010

Location: Office Chair

Posted: 19th May 2013 22:30

Link

Quote: "y#=y#+3"

Aren't the quaternions supposed to be between 0.0-1.0?

My hovercraft is full of eels

Back to top

Profile PM Email Website

Marl

13

Years of Service

User Offline

Joined: 19th Nov 2011

Location: Bradford, UK

Posted: 19th May 2013 22:49 Edited at: 19th May 2013 23:05

Link

Indeed, I can't see anywhere that says the values are angles.
(but then I can't see anywhere that says they are not)

For the command GetObjectQuatY, it states "Returns the Y component of the object's current rotation converted to a quaternion."

The use of the word "converted", suggests it's a bit more complex.

You can add the following to show the current angle

+ Code Snippet

print( str( y#) + " : " + str(  GetObjectAngleY( 1 )) )

Sadly, none of this helped me find an answer and the wiki page just gave me a headache

So I think we need a maths expert or the guy who included this in AppGameKit

EDIT:

Limiting to 0.0 to 1.0 with the following;

+ Code Snippet

		y# = y# + (3.0/360.0)
		y# = y# - floor( y# )

Does give Y rotation - kind of - but it's not the full picture yet

Back to top

Profile PM Email

Markus

Valued Member

20

Years of Service

User Offline

Joined: 10th Apr 2004

Location: Germany

Posted: 19th May 2013 23:04 Edited at: 19th May 2013 23:07

Link

this turn around a axis.

+ Code Snippet

//MR

setdisplayaspect(320/480.0)
setvirtualresolution(320,480)
setclearcolor(0,0,125)

createlightdirectional(1,0,-1,1,255,255,255)

CreateObjectcone( 1, 3,3,3 )
setobjectcolor(1,125,125,0,255)
SetObjectposition( 1,0,0,5 )

setcameraposition(1,0,0,-5)
setcameralookat(1,0,0,5,0)

do

    //axis
    ax#=0.0
    ay#=1.0
    az#=0.0

    //angle in degree
    theta# = theta# + 1.0
    w#   =   cos(theta#)
    x#   =   ax# * sin(theta#)
    y#   =   ay# * sin(theta#)
    z#   =   az# * sin(theta#)

    SetObjectRotationQuat( 1, w#,x#,y#,z# )

    sync()
loop

Back to top

Profile PM Email

Marl

13

Years of Service

User Offline

Joined: 19th Nov 2011

Location: Bradford, UK

Posted: 19th May 2013 23:28

Link

Markus, you are the man

I got more out of 10 short lines of code than the pages upon pages of math gibberish and doublespeak in the Wiki.

Makes sense that it would be sines and cosines if the range is 0 to 1, though it wouldn't have hurt to mention that in the docs.

Back to top

Profile PM Email

Sorry your browser is not supported!

AppGameKit Classic Chat / example of SetObjectRotationQuat