Moving and zooming using an orthogonal camera [SOLVED]

[bilygates]

Hello,

I've created an orthogonal camera using the following code:

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    ICameraSceneNode * camera = smgr->addCameraSceneNode();
    matrix4 ortho;
    ortho.buildProjectionMatrixOrthoLH(800, 600, 1, 500);
    camera->setProjectionMatrix(ortho, true);
    camera->setPosition(vector3df(0, 0, 0));
    camera->updateAbsolutePosition();

I was wondering if it is possible to move the camera around the X and Y axis, maybe even zooming or rotating it? Basically, if I want to move around the world, I could move the camera instead of moving every Scene Node. Likewise for zooming and rotating.

I have tried this:

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camera->setPosition(vector3df(150, 0, 0));

But that just distorts the image in a way that I do not quite understand.

Thanks in advance.

[Bear_130278]

I'm using the ortho camera... look

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//Camera
		Core.Ortho.buildProjectionMatrixOrthoLH  (Core.ZoomX,Core.ZoomZ,0.0f,6000.0f);
		Core.cam->setProjectionMatrix(Core.Ortho,true);
		Core.cam->setTarget(vector3df((float)Core.X,0.0f,(float)Core.Z));
		Core.cam->setPosition(vector3df((float)Core.X+Core.d_RX,Core.Elevation/*1.75*/*2000.0f,Core.d_RZ+(float)Core.Z));
		Core.cam->updateAbsolutePosition() ;	

Some description
X,Z - Camera target;
ZoomX,ZoomZ - Distance from the camera to the target
ZoomX/ZoomZ=4/3;(in my case)
d_RX,d_RZ - Rotation vars (i calc the rotation, and get the new positions of the camera based on the rotations)
Rotation calc:

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	vector3df t_pos=Core.cam->getTarget();
	vector3df c_pos=Core.cam->getAbsolutePosition();
	c_pos.rotateXZBy(15, t_pos);
	c_pos-=t_pos;
	Core.d_RX=c_pos.X;
	Core.d_RZ=c_pos.Z;

Here i rotate the camera around the target for +15 degrees;

Elevation - represents the angle between Y and Z axis.....

Hope it helps a little ))

[bilygates]

Thank you! I've managed to move the camera and zoom in. Yay! I couldn't get the camera to rotate, though. I get a blank screen without any objects.

Just to be sure I've made myself clear, this is how I would like to rotate the camera:



I've also tried things like this but without any luck:

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currentPosition = camera->getPosition();
currentPosition.rotateXZBy(15);
camera->setPosition(currentPosition);

[Bear_130278]

Ah.... but here you just need to :

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ICameraSceneNode::setRotation  ( const core::vector3df &  rotation  ) 

rotation.X,Y,Z - rotations in degrees for each axis, you need something like this:

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setRotation  (vector3df(0,0,45))

.... i guess

[bilygates]

I have tried that but it doesn't do anything.

Here is my project so far:

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#include "irrlicht.h"
#include <math.h>

using namespace irr;
using namespace core;
using namespace scene;
using namespace video;

int main()
{
    SIrrlichtCreationParameters deviceParameter;
        deviceParameter.DriverType = EDT_OPENGL;
        deviceParameter.AntiAlias = 4;
        deviceParameter.Bits = 32;
        deviceParameter.Fullscreen = false;
        deviceParameter.Vsync = false;
        deviceParameter.WindowSize = dimension2d<s32>(800, 600);

    IrrlichtDevice *device = createDeviceEx(deviceParameter);
    ISceneManager* smgr  = device->getSceneManager();
    IVideoDriver* driver = device->getVideoDriver();

    ICameraSceneNode * camera = smgr->addCameraSceneNode();
    matrix4 ortho;
    ortho.buildProjectionMatrixOrthoLH(800, 600, -1, 500);
    camera->setProjectionMatrix(ortho, true);
    camera->setPosition(vector3df(0, 0, 0));
    camera->setTarget(vector3df(0, 0, 1));
    camera->setRotation(vector3df(0, 0, 45));
    camera->updateAbsolutePosition();


    video::S3DVertex Vertices[4];
    Vertices[0] = video::S3DVertex(-25,25,0, 0,0,1, video::SColor(255,255,0,0), 0, 0);
    Vertices[1] = video::S3DVertex(25,25,0, 0,1,1, video::SColor(255,0,255,0), 1, 0);
    Vertices[2] = video::S3DVertex(25,-25,0, 1,0,0, video::SColor(255,0,0,255), 1, 1);
    Vertices[3] = video::S3DVertex(-25,-25,0, 0,0,1, video::SColor(255,255,255,255),0, 1);

    u16 indices[] = {0,1,2, 2,3,0};

    SMaterial myMaterial;
    myMaterial.Lighting = false;

    SMeshBuffer *buffer = new SMeshBuffer();
    buffer->append(Vertices, 4, indices, 6);

    SMesh *cubeMesh = new SMesh();
    cubeMesh->addMeshBuffer(buffer);

    ISceneNode *cubeSceneNode = smgr->addMeshSceneNode(cubeMesh);
    cubeSceneNode->getMaterial(0) = myMaterial;

    while (device->run())
    {
        driver->beginScene(true, true, video::SColor(0,100,100,100));
        smgr->drawAll();
        driver->endScene();
    }
}

This doesn't change anything:

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camera->setRotation(vector3df(0, 0, 45));

The square should appear rotated by 45 degrees, but it doesn't. I bet the solution is something extremely simple but I just can't figure it out. I'm using Irrlicht 1.7.1, by the way.

[Bear_130278]

Just in case ))
Check if your image node IS NOT a child of the camera node ))
Because in this case the image rotates with the camera ))

[blAaarg]

Cameras are strange because rotating them doesn't do anything (except rotate their children, if they have any) unless you first call:

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ICameraSceneNode::bindTargetAndRotation  ( bool  bound   )

Also, I think rotation vectors are in radians by default so you might need to change your rotation to:

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camera->setRotation(vector3df(0, 0, core::DEGTORAD * 45)

If that doesn't work then you should look into:

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ICameraSceneNode::setUpVector (...)

[bilygates]

Finally, this worked:

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camera->setUpVector(vector3df(cos(DEGTORAD * angle), sin(DEGTORAD * angle), 0));

I knew it was something extremely simple. Thank you blAaarg and Bear_130278 for your help.

[hybrid]

setRotation takes degrees, otherwise Radians is explicitly mentioned in the function name. Only exception are quaternions IIRC, but the API should tell you which values to insert.