Function which converts 2D to 3D

[gogo]

Please image to let a character move to the place which is pointed by a mouse cursor in 3D RPG. So I am looking for a function of Irrlicht which converts 2D coordinate to 3D one.
Which func to use?

[Vsk]

Please image to let a character move to the place which is pointed by a mouse cursor in 3D RPG. So I am looking for a function of Irrlicht which converts 2D coordinate to 3D one.
Which func to use?

What you are looking for is call "picking"; search for that.
In a easy way (limited) picking is done by proyecting (x,y) coord from the screen + perpendicular vector (parallel to cam->getTarget vector).
The first object that this line intersect is the one which is picked.

You can easily use irrlicht collision detection for that, if there is not something already done by some user.

[huydotnet]

It mean mouse picking, i think so.
first, init some variable:

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irr::core::position2d<s32> mousePos; //This is mouse position (in 2D)
core::vector3df intersection; //Mouse position in 3d (after convert)
core::triangle3df tri; 
core::line3df ray;
scene::ITriangleSelector* selector;

then, put this in your init function

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selector = smgr->createTriangleSelector(smgr->getMesh("Data/terrain.b3d"),smgr->getSceneNodeFromId(100));
	smgr->getSceneNodeFromId(100)->setTriangleSelector(selector);
	
	selector->drop();

in this code, we will create TriangleSelector from mesh file from Data/terrain.b3d.
and put this in your mainloop

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pos = device->getCursorControl()->getPosition();
	ray = smgr->getSceneCollisionManager()->getRayFromScreenCoordinates(pos,smgr->getActiveCamera());
	smgr->getSceneCollisionManager()->getCollisionPoint(ray,selector,intersection,tri);

now, when you click mouse in terrain scene node, it will set the 3d position to intersection.

[Vsk]

It mean mouse picking, i think so.
first, init some variable:

Code: Select all

irr::core::position2d<s32> mousePos; //This is mouse position (in 2D)
core::vector3df intersection; //Mouse position in 3d (after convert)
core::triangle3df tri; 
core::line3df ray;
scene::ITriangleSelector* selector;

then, put this in your init function

Code: Select all

selector = smgr->createTriangleSelector(smgr->getMesh("Data/terrain.b3d"),smgr->getSceneNodeFromId(100));
	smgr->getSceneNodeFromId(100)->setTriangleSelector(selector);
	
	selector->drop();

in this code, we will create TriangleSelector from mesh file from Data/terrain.b3d.
and put this in your mainloop

Code: Select all

pos = device->getCursorControl()->getPosition();
	ray = smgr->getSceneCollisionManager()->getRayFromScreenCoordinates(pos,smgr->getActiveCamera());
	smgr->getSceneCollisionManager()->getCollisionPoint(ray,selector,intersection,tri);

now, when you click mouse in terrain scene node, it will set the 3d position to intersection.

Hey!, you should add that code into FAQ&& HOWTO&&etc, I think is very useful for newbies and not newbies.

[rogerborg]

Are you being sarcastic? I honestly can't tell.

Note: this is demonstrated in example 07, cunningly titled "Collision".

[Vsk]

Are you being sarcastic? I honestly can't tell.

Note: this is demonstrated in example 07, cunningly titled "Collision".

haha, that's right.
I just forgot it (I have never used).

[gogo]

[Sigutis]

gogo's file would make sense if it had any source included