rotation through 3 vertexes problem( Gimbal Lock?)

Gamestudio Links

Zorro Links

What are you working on?
by rayp. 10/15/25 20:44

Help!
by VoroneTZ. 10/14/25 05:04

Zorro 2.70
by jcl. 10/13/25 09:01

ZorroGPT
by TipmyPip. 10/12/25 13:58

AUM Magazine

Latest Screens

2 registered members (TipmyPip, AndrewAMD), 7,000 guests, and 2 spiders.

Key: Admin, Global Mod, Mod

Newest Members

joenxxx, Jota, krishna, DrissB, James168
19170 Registered Users

Print Thread

Rate Thread

rotation through 3 vertexes problem( Gimbal Lock?) #392852 01/28/12 19:15 01/28/12 19:15
Joined: Sep 2007 Posts: 101 Luxembourg K krial057 OP Member
krial057 OP Member K Joined: Sep 2007 Posts: 101 Luxembourg	Hey, I tried to implement a new feature into my patheditor. It should give the possibilty to "export" paths from modeling programs into gamestudio. The idea is the following: - In the modeling software render a path with triangles: http://dl.dropbox.com/u/6859456/3dgs/Bild_2.bmp - Load it in gamestudio and run my script: Php Code: for(int i;i<vertexcount;i+=3) { you=nodeCreate(); vec_set(you.x, vec_for_vertex(ver1,ent,i+2)); vec_for_vertex(ver3,ent,i); vec_for_vertex(ver1,ent,i+1); vec_for_vertex(ver2,ent,i+2); vec_set(tmpVec,ver1.x); vec_add(tmpVec,ver2.x); vec_scale(tmpVec,0.5); vec_set(panDir,ver1.x); vec_sub(panDir,ver2.x); vec_to_angle(tmpAng,panDir); you.pan=tmpAng.pan; you.tilt=tmpAng.tilt; vec_sub(tmpVec,ver3); vec_cross(panDir,panDir,tmpVec); vec_to_angle(tmpAng,panDir); you.roll=tmpAng.tilt; } Everything works fine, but when the tilt value comes nearer to -90, the pan value plays crazy(it gets from 180 to 0) and the tilt value goes back instead of continuing (so it is in inverse roation). It is difficult to explain, but I think this guy here had the same problem: http://www.opserver.de/ubb7/ubbthreads.php?ubb=showflat&Number=166452 regards Alain Last edited by krial057; 01/29/12 12:42.

Re: rotation through 3 vertexes problem( Gimbal Lock?) [Re: krial057] #392854 01/28/12 21:09 01/28/12 21:09
Joined: Dec 2008 Posts: 1,218 Germany Rackscha Serious User
Rackscha Serious User Joined: Dec 2008 Posts: 1,218 Germany	Iam not shure about it, but maybe you do not handle the roll value correctly? For example why do you use you.rool = tmpAng.tilt int the last line? PS: iam totally bad at this rotation stuff, when it comes to reading it Last edited by Rackscha; 01/28/12 21:09. MY Website with news of my projects: (for example my current Muliplayer Bomberman, GenesisPrecompiler for LiteC and TileMaster, an easy to use Tile editor) Sparetime-Development

Re: rotation through 3 vertexes problem( Gimbal Lock?) [Re: Rackscha] #392896 01/29/12 12:41 01/29/12 12:41
Joined: Sep 2007 Posts: 101 Luxembourg K krial057 OP Member
krial057 OP Member K Joined: Sep 2007 Posts: 101 Luxembourg	It's difficult to explain my idea to rotate it... Here is a picture of a triangle with the vectors: before the second vec_to_angle, panDir gets crossed (the violet vector). Because of this, the roll and tilt values somehow get "switched". Further more, the vec_to_angle function does not modify the roll value. I'm not the best at rotation stuff too, but this was the only way I got it tow work... I believe there is a better way to do this. Last edited by krial057; 01/29/12 12:43.