scene node shakes when attached to fps camera

[thatdudeoverthere]

The title basically sums up the problem. If I move left or right the scene node attached to the fps camera jerks and shakes really bad at first and after a few seconds lessens, but is still visibly shaking. If I move forward or backwards or rotate the camera all is fine. It's just the strafing movements that causes a problem. I went so far as to open up the second example that comes with Irrlicht and attached a scene node there and the problem still persists, but I'm getting around ~100 fps. And I don't remember having this problem with older versions of the Irrlicht (or maybe I'm not remembering correctly)

This is for example how I'm attaching the scene node to the camera

Code: Select all

 
scene::ICameraSceneNode* PlayerCamera = smgr->addCameraSceneNodeFPS(...etc...);
 
scene::IAnimatedMesh* gun = smgr->getMesh("gun.x");
scene::IAnimatedMeshSceneNode* gunNode = smgr->addAnimatedMeshSceneNode(gun);
gunNode->setPosition(core::vector3df(10,5,20));
gunNode->setParent(PlayerCamera);
 
 

any help is appreciated.

[Mel]

the problem is the desynchronization between the camera and the gun. I think it can be solved by calling the updateAbsolutePosition() of the camera and the gun before the rendering. But i can't tell 100% for sure.

[thatdudeoverthere]

Alright I'll give that a try and give some feed back on how it goes.

[thatdudeoverthere]

Okay that didn't work exactly, but I did some experimenting and found that if I do...

Code: Select all

 
    while(device->run())
    {
        if (device->isWindowActive())
        {
            driver->beginScene(true, true, video::SColor(255,200,200,200));
            //first call to drawAll()
            smgr->drawAll();
 
            camera->updateAbsolutePosition();
            gunnode->updateAbsolutePosition();
 
             //second call to drawAll()
            smgr->drawAll();
            driver->endScene();
 
                            ........
 

and then proceed to move left/right with the camera it draws two instances of the node (from the two calls to 'smgr->drawAll()') but only one of the two nodes does the shaking the other one behaves like I want...

[chronologicaldot]

With respect to what Mel suggested, what did you try exactly?
This?:

Code: Select all

 
while(device->run())
    {
        if (device->isWindowActive())
        {
            camera->updateAbsolutePosition();
            gunnode->updateAbsolutePosition();
 
            driver->beginScene(true, true, video::SColor(255,200,200,200));
            smgr->drawAll();
            driver->endScene();
 

[thatdudeoverthere]

@chronologicaldot Yes I tried that code snippet, but it did not work.

[chronologicaldot]

Hmm.. It sounds like the position updating is the problem. How do you know that the node isn't shaking forward and backward when you move those directions? Is the camera positioned directly behind the node?
I'd try setting the position of the note to 0,0,0 and see if the problem persists.

Code: Select all

 
gunNode->setPosition(core::vector3df(0,0,0));
 

[thatdudeoverthere]

yep the problem still persists even with the position set to (0,0,0) and still no shaking from moving forwards or backwards...

[chronologicaldot]

Hm... It might be with IAnimatedMeshSceneNode because of post-rendering activity. Try a regular scene node and see if the problem persists.

[wing64]

Try call PlayerCamera->render( ) before drawall(). Maybe it help.