Help - Wheel Rotation

kaliber · Post by **kaliber** » Sat Dec 11, 2010 11:35 pm

I have a wheel and i want to rotate it like a wheel

im doing Y rotation then if im doing the Z rotation it's like the Z1, i want it like the Z2. Any Help ??

CodeDragon · Post by **CodeDragon** » Sun Dec 12, 2010 12:05 am

Hmm, Try to use the node->Rotate,
You can let it rotate with a simple loop.

kaliber · Post by **kaliber** » Sun Dec 12, 2010 12:25 am

CodeDragon wrote:Hmm, Try to use the node->Rotate,
You can let it rotate with a simple loop.

yes i did, but its not rotate right.

when the wheel straight, the Z rotation make the whell spin clockwise. but when its not staight(Y r0tation) the wheell spin awfully.

Radikalizm · Post by **Radikalizm** » Sun Dec 12, 2010 12:44 am

what you want is a local transformation

check out this thread http://irrlicht.sourceforge.net/phpBB2/ ... hp?t=42036

kaliber · Post by **kaliber** » Sun Dec 12, 2010 12:48 am

Radikalizm wrote:what you want is a local transformation

check out this thread http://irrlicht.sourceforge.net/phpBB2/ ... hp?t=42036

okay, finnaly

kaliber · Post by **kaliber** » Sun Dec 12, 2010 12:59 am

err, now the code : Node->setRotation(..) is ignored

lazerblade · Post by **lazerblade** » Sun Dec 12, 2010 2:45 am

Are you talking about the line in my function or are you talking about applying the rotation yourself? Keep in mind that calling "setRotation" on a scene node is NOT local and is NOT affected by the node's current rotation.

BTW, it's great to see other people using this code.

kaliber · Post by **kaliber** » Sun Dec 12, 2010 2:58 am

here's my code :

Code: Select all

if(rcv.IsKeyDown(KEY_KEY_D))
			rotateNode(MyNode,vector3df(0,0.1f,0));
		else
			rotateNode(MyNode,vector3df(0,0,1));

i want the wheel turn when i press the D key, but it turn in wrong.
the wheel spin well when im not press the D key.

lazerblade · Post by **lazerblade** » Sun Dec 12, 2010 3:06 am

Hmmm...

You could try increasing the amount that the wheel turns along the Y axis,
0.1 won't go very fast.

I would try something like:

Code: Select all

if(rcv.IsKeyDown(KEY_KEY_D)) 
         rotateNode(MyNode,vector3df(0,1,0)); 
      else 
         rotateNode(MyNode,vector3df(0,0,1));

kaliber · Post by **kaliber** » Sun Dec 12, 2010 3:20 am

it seem the Y Axis rotated by this code :

Code: Select all

rotateNode(MyNode,vector3df(0,0,1));

the speed is normal, i did change the 0.1f value to 1.

lazerblade · Post by **lazerblade** » Sun Dec 12, 2010 3:28 am

Uhm, actually the last parameter is the Z axis. But as long as you get the
effect you want, it doesn't matter.

I'm not sure I understand your problem perfectly, is the node rotating in the
wrong direction, wrong axis, or is it not rotating at all?
If it's rotating in the wrong direction, you could try negating the value like so:

Code: Select all

rotateNode(MyNode, vector3df(0,-0.1f,0))

kaliber · Post by **kaliber** » Sun Dec 12, 2010 3:46 am

its rotating

but when its rotate in Z axis, the Y Axis rotated

lazerblade · Post by **lazerblade** » Sun Dec 12, 2010 3:52 am

Okay, I think I understand the problem then.

You see the XYZ axis', are relative to the mesh. They are completely unaffected by the global axis. So whatever got exported from the 3d modeler as the Y axis, will be preserved in Irrlicht.
So in short, your XYZ axis' might be different for every mesh/sceneNode. Try rotating along a different axis and see what happens.

BTW I'm online right now in the #irrlicht channel on irc.freenode.net, so you might want to join it there so that we both won't have to go through this agonizing pain and mental anguish of checking the forum again and again.

kaliber · Post by **kaliber** » Sun Dec 12, 2010 4:01 am

hahaha

ok

kaliber · Post by **kaliber** » Sun Dec 12, 2010 7:04 am

any help ???
i want to make the wheel spin while turning
here my whole code :

Code: Select all

#include <irrlicht.h>
#include "eventreceiver.h"

using namespace irr;

using namespace core;
using namespace scene;
using namespace video;
using namespace io;
using namespace gui;

#ifdef _IRR_WINDOWS_
#pragma comment(lib, "Irrlicht.lib")
#pragma comment(linker, "/subsystem:windows /ENTRY:mainCRTStartup")
#endif

/*
  ==========
    rotateNode -- rotate a scene node locally
  ==========
*/
void rotateNode(irr::scene::ISceneNode *node, irr::core::vector3df rot)
{
    irr::core::matrix4 m;

    m = node->getAbsoluteTransformation();

    irr::core::matrix4 n;
    n.setRotationDegrees(rot);

    m *=n;

    node->setRotation(m.getRotationDegrees());
    node->updateAbsolutePosition();

} 


	
int main(){

	IrrlichtDevice* device = createDevice(video::EDT_DIRECT3D9,dimension2d<u32>(800,600),32);
	MyEventReceiver rcv;

	device->setEventReceiver(&rcv);
	
	ISceneManager* Mgr = device->getSceneManager();
	IVideoDriver* Video = device->getVideoDriver();

	IMeshSceneNode* Wheel= Mgr->addMeshSceneNode(Mgr->getMesh("ban.x"));
	
	ICameraSceneNode* kamera = Mgr->addCameraSceneNodeFPS();//,vector3df(70,20,5),vector3df(0,0,0));

	
	while(device->run()){
				
		rotateNode(Wheel,vector3df(0,0,1));
		rotateNode(Wheel,vector3df(0,1,0));

		Video->beginScene(true,true,SColor(255,255,255,255));
		Mgr->drawAll();
		Video->endScene();
		
	}
	
device->drop();
return 0;
}