Rays Cannot Detect Billboards

[magicaxis]

Hello all, I realize this is a common question, but I have read and attempted every response on the internet and have had no dice so far.

I have a billboard hovering over an item in space. I want to click on the billboard, and the camera zooms in on the item. The camera zoom and the item are fine, the problem lies in here:

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Ogre::Ray mouseRay = mCamera->getCameraToViewportRay(mousePos.d_x/float(arg.state.width), mousePos.d_y/float(arg.state.height));
	mRaySceneQuery = mCamera->getSceneManager()->createRayQuery(Ray());
	mRaySceneQuery->setSortByDistance(true);

	if (currSceneType == SCENE_SSVIEW) mRaySceneQuery->setQueryMask(SUN_MASK | SC_MASK | PLANET_MASK | PLANET_BTN_MASK | Ogre::SceneManager::FX_TYPE_MASK);
	//I have tried setQueryTypeMask, but that makes both the keyboard and the mouse become unresponsive.
	mRaySceneQuery->setRay(mouseRay);

	RaySceneQueryResult result = mRaySceneQuery->execute();
	rayHitData myHit = RaycastFromPoint(mRaySceneQuery, mouseRay);

No matter what I do, "result" never includes the billboard. I have tried making the billboard an SC_MASK, an FX_TYPE_MASK, everything i can think of. As a result, myHit never contains the billboard, and the click does not register. Can someone please help, this is driving me up the wall!

Also note: for some reason, Ogre::SceneManager::FX_TYPE_MASK; always comes back as about 536 billion. The other enums are all sensible uint32s, but that one is wild.

[areay]

Hi there,

I *think* that RaySceneQuery will only return objects that subclass 'Ogre::Movable' and billboards are not derived from that base. I see you've tried to force the rayquery to use FX as a query mask anyway

Maybe you could try another approach where you work out the screen coordinates of the billboard and compare that to the mouse's position when it's clicked.

[Kojack]

Billboards always face the camera, but ray scene queries don't know the camera direction so can't tell which direction the billboard is facing (plus if you have two cameras looking at the billboard from different directions, it would have two facing directions) and therefore can't test for collision.

I'd second the idea of working in screen space.

[magicaxis]

YES! It took a looooot of tinkering in the mouse controller, but i've got it registering! all i have to do now is make the clickable area scale to the size of the icon!

[areay]

Good stuff pal

[chaosavy]

You could also make a manual object - a "2d" rectangle - give it a material of your billboard and then ray scene queries should pick it up, though you'd be giving up a lot of neatness of billbaords (always facing camera, etc).

[FireSpy]

So, what was the secret?

[jacmoe]

I think the secret is to know the location of the billboard(s) and then cast a ray against a plane created from that point and the camera orientation.
That really depends on how the billboards are constructed.
Otherwise it would be easier to cast a ray against a bounding volume.

[magicaxis]

I basically compared the mouses position with the position of the icon on the screen. If the mouse was within x (x being the width of the billboard), then it was clicked. Here's my code <3

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CEGUI::Point absMouse = CEGUI::MouseCursor::getSingleton().getPosition();

	if (seperation > SCI->getAttachedObject("iconSet")->getRenderingDistance()){
		return false;
	}

	if (absMouse.d_x >= SCIx - 30 &&
		absMouse.d_x <= SCIx + 30 &&
		absMouse.d_y >= SCIy - 30 &&
		absMouse.d_y <= SCIy + 30)//change 30 if the icon is resized
	{
		return true;
	}
	else
	{
 		return false;
	}

Oh yeah, SCIx and SCIy are SpaceCraftIconXlocation. I used this to get the 2d coordinates of the icon on the screen:

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Vector3 eyeSpacePos = mCamera->getViewMatrix(true) * SCI->convertLocalToWorldPosition(SCI->getPosition());
	if (eyeSpacePos.z < 0) 
	{
		Vector3 screenSpacePos = mCamera->getProjectionMatrix() * eyeSpacePos;
        SCIx = screenSpacePos.x;
        SCIy = screenSpacePos.y;

[lordbeast]

Ouch... this is overdose!
Simplest way is to use RaySceneQueryType method

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mRayScnQuery = mSceneMgr->createRayQuery(Ogre::Ray());
mRayScnQuery->setQueryTypeMask(SceneManager::FX_TYPE_MASK);

There are 6 types of QueryTypeMask defined in the SceneManager class as static members:

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WORLD_GEOMETRY_TYPE_MASK //Returns world geometry.
ENTITY_TYPE_MASK         //Returns entities.
FX_TYPE_MASK             //Returns billboardsets / particle systems.
STATICGEOMETRY_TYPE_MASK //Returns static geometry.
LIGHT_TYPE_MASK          //Returns lights.
USER_TYPE_MASK_LIMIT     //User type mask limit.

Intermediate Tutorial 3

[areay]

Ouch... this is overdose!
Simplest way is to use RaySceneQueryType method

Did you not see the part where OP tried that and it didn't work? And that he wants to test against a billboard and not a billboardset?

[lordbeast]

i`m heedless. Sorry.