Camera Terrain Collision in a wxWidgets Frame

[gbutcher]

Okay, I have a test application that paints the Irrlicht viewport in a wxWidgets frame. I'm animating the camera with the wxWidgets event routines, like this:

Code: Select all

void wxirrlichtFrm::wxirrlichtFrmKeyDown(wxKeyEvent& event)
{
	// insert your code here
	if (!cam) return;
	float sp = 10.0f;
	int k = event.GetKeyCode();
	core::vector3df whereat = cam->getPosition();
	core::vector3df lookat = cam->getTarget();
	core::vector3df delta = (whereat - lookat).normalize();
	if (event.GetModifiers() == wxMOD_SHIFT) sp = 1.0f;
	if (k == WXK_UP) {
        whereat.X -= delta.X*sp; whereat.Z -= delta.Z*sp;
        lookat.X -= delta.X*sp; lookat.Z -= delta.Z*sp;
    }
    if (k == WXK_DOWN) {
        whereat.X += delta.X*sp; whereat.Z += delta.Z*sp;
        lookat.X += delta.X*sp; lookat.Z += delta.Z*sp;
    }
    if (k == WXK_LEFT) {
        delta.rotateXZBy(90.0f,core::vector3df(0,0,0));
        whereat.X -= delta.X*sp; whereat.Z -= delta.Z*sp;
        lookat.X -= delta.X*sp; lookat.Z -= delta.Z*sp;
    }
    if (k == WXK_RIGHT) {
        delta.rotateXZBy(90.0f,core::vector3df(0,0,0));
        whereat.X += delta.X*sp; whereat.Z += delta.Z*sp;
        lookat.X += delta.X*sp; lookat.Z += delta.Z*sp;
    }

    if (k == WXK_PAGEUP) {
        whereat.Y += 10.0f;
        lookat.Y += 10.0f;
    }
    if (k == WXK_PAGEDOWN) {
        whereat.Y -= 10.0f;
        lookat.Y -= 10.0f;
    }
    cam->setPosition(whereat);
    cam->setTarget(lookat);
    cam->updateAbsolutePosition();
}

I've attached a collision response animator to the camera right after loading it from the .irr file:

Code: Select all

    ITerrainSceneNode* terrain = (ITerrainSceneNode*) smgr->getSceneNodeFromType(ESNT_TERRAIN);
    if (terrain) {
        ITriangleSelector* world = smgr->createTriangleSelector(terrain->getMesh(),terrain);
        terrain->setTriangleSelector(world);
        world->drop();
        if (world) {
            ISceneNodeAnimator* anim = smgr->createCollisionResponseAnimator(world, cam, core::vector3df(30.0f,60.0f,30.0f), core::vector3df(0.0f,0.0f,0.0f), core::vector3df(0.0f,0.0f,0.0f));
            if (anim) {
                cam->addAnimator(anim);
                anim->drop();
            }
            else Log("Camera collision response animator creation failed.");
        }
        else Log("Terrain triangle selector creation failed.");
    }
    else Log("No terrain with which to create collision.");

I know the collision animator is working because I've set the gravity Y to a negative number and the camera falls, but I'm driving right through the terrain. I've inspected the FPS camera and I can't determine what I need to do in the wxWidgets event handler that's being done over there. I've also implemented the equivalent animator in a non-wxWidgets version of the program, per the tutorial, and it works fine. Any insight offered would be appreciated...

[vitek]

I've never seen someone try to use a regular triangle selector with the terrain mesh. I don't think that mesh will have valid indices until after it has been rendered at least once. You might try to see if the returned mesh actually has any mesh buffers, vertices and indices in it. I doubt that it will.

You should probably use smgr->createTerrainTriangleSelector() instead.

Travis

[gbutcher]

Doh!

Works fine now... thanks, vitek.

[rogerborg]

I've never seen someone try to use a regular triangle selector with the terrain mesh. I don't think that mesh will have valid indices until after it has been rendered at least once. You might try to see if the returned mesh actually has any mesh buffers, vertices and indices in it. I doubt that it will.

Yup, it's bogus. I'm not sure why it even has a getMesh() method. You could create an SMesh from getMeshBufferForLOD() and then use that, but it'd be hugely inefficient compared to a terrain triangle selector.