Irrlicht Engine

Posted: **Thu Jun 07, 2007 4:32 pm**

Hi folks!

I've a very simple level setup at the moment. The player has an FPS style camera, is stood in a large room with a cube at the centre (the idea is the player throws rocks at the deformable cube, for a deformation project). I have recently noticed that all of the meshes are quivering slightly in the y-direction. It's only slight at first, but the more I move around the level the greater the quivering gets, and finally the player camera begins to hop up and down furiously before falling through the level.

I'm guessing it's something to do with the collision detection between the player and the level itself (causing the player to "quiver" his way through the base). My current collision code is as follows:

Code: Select all

IAnimatedMesh* mesh = smgr->getMesh("collisionplayroom.b3d");
ISceneNode* node = 0;

if (mesh)
    node = smgr->addOctTreeSceneNode(mesh->getMesh(0));

ITriangleSelector* selector = 0;

if (node)
{
        node->setPosition(vector3df(-16,0,0));
        selector = smgr->createOctTreeTriangleSelector(mesh->getMesh(0), node, 128);
        node->setTriangleSelector(selector);
        selector->drop();
}

m_cam = smgr->addCameraSceneNodeFPS(0,100,30);
m_cam->setPosition(vector3df(-20,7,0));
m_cam->setTarget(vector3df(50, 0, 0));

ISceneNodeAnimator* anim = smgr->createCollisionResponseAnimator(
    selector, m_cam, vector3df(2,3,2),
    vector3df(0,-10,0),
    vector3df(0,3,0));

m_cam->addAnimator(anim);
anim->drop();

Have I done something incorrect here, or does the problem seem to be coming from elsewhere? Thankyou for any help.. this one really is confusing me!

Posted: **Thu Jun 07, 2007 4:39 pm**

I seem to have found the source of the problem, but not a solution. As well as the selector mentioned below, I have a second to deal with cube collisions, setup as follows:

Code: Select all

selector2 = smgr->createOctTreeTriangleSelector(cubeMesh, cubeSceneNode, 128);
cubeSceneNode->setTriangleSelector(selector2);
selector2->drop();

ISceneNodeAnimator* anim = smgr->createCollisionResponseAnimator(
selector, m_cam, vector3df(2,3,2),vector3df(0,-10,0),vector3df(0,3,0));

ISceneNodeAnimator* anim2 = smgr->createCollisionResponseAnimator(
selector2, m_cam, vector3df(2,3,2),vector3df(0,-10,0),vector3df(0,3,0));

m_cam->addAnimator(anim);
m_cam->addAnimator(anim2);

anim->drop();
anim2->drop();

Removing the second animator, "anim2" removes the problem, but also disables collision detection with my cube. Will I have to mount a second node to my cam node for collision detection with the cubic mesh?

Posted: **Thu Jun 07, 2007 7:56 pm**

add both selectors into a metaSelector, then use that in the collision response animator. you shouldn't use two collision response animators on one node.

Posted: **Thu Jun 07, 2007 8:42 pm**

That worked perfectly, thanks bitplane!

I seem to only have one visual problem left now. If I form my deformable cube mesh from anymore than 27 vertices, looking upwards causes the bottom of the mesh to appear invisible. Looking back down again will cause the bottom of the mesh to pop back into view. This occurs in both windowed and full screen modes. Any idea what could be causing this one?

Posted: **Fri Jun 08, 2007 2:12 pm**

I seem to have fixed the last problem - I believe my mesh normals weren't quite correct.

Irrlicht Engine

Quivering Meshes and Falling Through the Level

Quivering Meshes and Falling Through the Level