[solved]Camera rotation and translation

Don’t understand, how to move camera parallel to world’s left, right, forward and backward vectors, but with camera’s y rotation component(blue arrow on the image):
Now I’m trying to multiply node rotation matrix with move vector and translate it in local space. But in result camera moves to north/south etc. regardless of it’s rotation:

if(input->GetMousePosition().y_ < BORDER_OFFSET) { Quaternion currentRot = _cameraNode->GetRotation(); Vector3 rotated = currentRot.Inverse().RotationMatrix() * Vector3(0,0,CAMERA_VELOCITY); _cameraNode->Translate(rotated); } if(input->GetMousePosition().y_ > graphics->GetHeight() - BORDER_OFFSET) { Quaternion currentRot = _cameraNode->GetRotation(); Vector3 rotated = currentRot.Inverse().RotationMatrix() * Vector3(0,0,-CAMERA_VELOCITY); _cameraNode->Translate(rotated); }

Update: now camera works as expected, but there are strange slow down when yaw angle is near +/90:

void LevelCamera::VerticalTranslate(float amount)
{
    Quaternion currentRot = _cameraNode->GetRotation();
    Matrix3 rotation = currentRot.Inverse().RotationMatrix();

    rotation.m00_ = 1;
    rotation.m10_ = 0;
    rotation.m20_ = 0;
    rotation.m01_ = 0;
    rotation.m02_ = 0;
    LOGINFO(String(currentRot.YawAngle()));
    if(currentRot.YawAngle() < -90 || currentRot.YawAngle() > 90)
            amount *= -1;
    Vector3 rotated = rotation * Vector3(0,0,amount);
    _cameraNode->Translate(rotated);
}

void LevelCamera::HorizontalTranslate(float amount)
{
    Quaternion currentRot = _cameraNode->GetRotation();
    Matrix3 rotation = currentRot.Inverse().RotationMatrix();
    rotation.m00_ = 1;
    rotation.m10_ = 0;
    rotation.m20_ = 0;
    rotation.m01_ = 0;
    rotation.m02_ = 0;
    Vector3 rotated = rotation * Vector3(amount,0,0);
    _cameraNode->Translate(rotated);
}

void LevelCamera::Update()
{
    UI* ui = GetSubsystem<UI>();
    Input* input = GetSubsystem<Input>();
    Graphics *graphics = GetSubsystem<Graphics>();

    if (ui->GetFocusElement())
        return;

    if(input->GetMousePosition().y_ < BORDER_OFFSET)
        VerticalTranslate(CAMERA_VELOCITY);
    if(input->GetMousePosition().y_ >  graphics->GetHeight() - BORDER_OFFSET)
        VerticalTranslate(-CAMERA_VELOCITY);
    if(input->GetMousePosition().x_ < BORDER_OFFSET)
        HorizontalTranslate(-CAMERA_VELOCITY);
    if(input->GetMousePosition().x_ >  graphics->GetWidth() - BORDER_OFFSET)
        HorizontalTranslate(CAMERA_VELOCITY);
    if (input->GetMouseButtonDown(MOUSEB_RIGHT))
    {
        IntVector2 mouseMove = input->GetMouseMove();
        _yaw += MOUSE_SENSITIVITY * mouseMove.x_;
        _pitch += MOUSE_SENSITIVITY * mouseMove.y_;
        Vector3 hitPos;
        Drawable* hitDrawable;
        if(Raycast(250.0f, hitPos, hitDrawable, true))
        {
            _cameraNode->RotateAround(hitPos, Quaternion(_yaw, Vector3(0,1,0)), TS_WORLD);
            if(abs((int)_pitch) < 20 )
            {
                if(_cameraNode->GetRotation().PitchAngle() < 45 &&  _pitch < 0)
                    _cameraNode->RotateAround(hitPos, Quaternion(_pitch, _cameraNode->GetDirection().CrossProduct(Vector3(0,1,0))), TS_WORLD);
                if(_cameraNode->GetRotation().PitchAngle() > 10 && _pitch > 0)
                    _cameraNode->RotateAround(hitPos, Quaternion(_pitch, _cameraNode->GetDirection().CrossProduct(Vector3(0,1,0))), TS_WORLD);
            }
        }

        _yaw = 0;
        _pitch = 0;
    }
    int wheelMove = input->GetMouseMoveWheel();
    if( wheelMove != 0 && abs((int)wheelMove) < 2)
    {
        Camera *camera = _cameraNode->GetComponent<Camera>();
        float oldZoom = camera->GetZoom();
        if(oldZoom > 0.5f && wheelMove < 0)
            camera->SetZoom(oldZoom + wheelMove*WHEEL_SENSITIVITY);
        if(oldZoom < 4 && wheelMove > 0)
            camera->SetZoom(oldZoom + wheelMove*WHEEL_SENSITIVITY);
    }
}

If I have to change matrixes itself, I’m doing something wrong:(

mb it helps

  1. in editor setup

  2. runtime setup

//application public:
	SharedPtr<Node> playerNode;
	RigidBody* playerRigidbody;

	struct
	{
		SharedPtr<Node> node;
		Camera* component;
		Viewport* viewport;
		float yaw_;
		float pitch_;
		float roll_;

	} camera;
//app:Start()
		playerNode = scene_->GetChild("player", true);
		playerRigidbody = playerNode->GetComponent<RigidBody>();
		camera.node = scene_->GetChild("camera", true);
		camera.component = camera.node->GetComponent<Camera>();
  1. updates
	void HandleUpdate(StringHash eventType, VariantMap& eventData)
	{
		using namespace Update;
		float timeStep = eventData[P_TIMESTEP].GetFloat();
		MoveCamera(timeStep);


		if (playerRigidbody) 
		{
			Input* input = GetSubsystem<Input>();
			Quaternion worldRotation = camera.node->GetWorldRotation();
			worldRotation.z_ = 0;

			Vector3 dir = Vector3::ZERO;

			if (input->GetKeyDown('W')) 
			{
				dir += Vector3::FORWARD;
			}

			if (input->GetKeyDown('S'))
			{
				dir += Vector3::BACK;
			}

			if (input->GetKeyDown('D'))
			{
				dir += Vector3::RIGHT;
			}

			if (input->GetKeyDown('A'))
			{
				dir += Vector3::LEFT;
			}

			if (input->GetKeyDown(KEY_SPACE))
			{
				dir += Vector3::UP;
			}


			const float speed = 1800.0f;

			if (dir.Length() > 0)
				playerRigidbody->SetLinearVelocity(speed * (worldRotation * dir) * timeStep);
		}
	}
	void MoveCamera(float timeStep)
	{
		Input* input = GetSubsystem<Input>();
		const float MOUSE_SENSITIVITY = 0.1f;
		IntVector2 mouseMove = input->GetMouseMove();

		camera.yaw_ += MOUSE_SENSITIVITY * mouseMove.x_;
		camera.pitch_ += MOUSE_SENSITIVITY * mouseMove.y_;
		camera.pitch_ = Clamp(camera.pitch_, -90.0f, 90.0f);
		camera.node->SetWorldRotation(Quaternion(camera.pitch_, camera.yaw_, 0.0f));

	}

I can confirm that the previous approach works. I use it for my isometric like view.

[quote=“codingmonkey”]mb it helps
…[/quote]
Thanks, now I found a right way to move camera:

[code]void LevelCamera::VerticalTranslate(float amount)
{
float currentRot = _cameraNode->GetRotation().YawAngle();
Quaternion distilledRot;
distilledRot.FromAngleAxis(currentRot, Vector3(0,1,0));
Vector3 rotated = distilledRot.RotationMatrix() * Vector3(0,0,amount);
_cameraNode->Translate(rotated, TS_WORLD);
}

void LevelCamera::HorizontalTranslate(float amount)
{
float currentRot = _cameraNode->GetRotation().YawAngle();
Quaternion distilledRot;
distilledRot.FromAngleAxis(currentRot, Vector3(0,1,0));
Vector3 rotated = distilledRot.RotationMatrix() * Vector3(amount,0,0);
_cameraNode->Translate(rotated, TS_WORLD);
}
[/code]
But your rotation code is about rotating camera itself, not around current screen center. I still can not understand, how to rotate camera around current viewport center projection, if camera ray can not intersect anything:

if(Raycast(hitPos, hitDrawable))//need some fallback
        {
            _cameraNode->RotateAround(hitPos, Quaternion(_yaw, Vector3(0,1,0)), TS_WORLD);
            if(abs((int)_pitch) < 20 )
            {
                if(_cameraNode->GetRotation().PitchAngle() < 45 &&  _pitch < 0)
                    _cameraNode->RotateAround(hitPos, Quaternion(_pitch, _cameraNode->GetDirection().CrossProduct(Vector3(0,1,0))), TS_WORLD);
                if(_cameraNode->GetRotation().PitchAngle() > 10 && _pitch > 0)
                    _cameraNode->RotateAround(hitPos, Quaternion(_pitch, _cameraNode->GetDirection().CrossProduct(Vector3(0,1,0))), TS_WORLD);
            }
        }

...

bool LevelCamera::Raycast(Vector3 &hitPos, Drawable *&hitDrawable)
{
    hitDrawable = 0;

    UI* ui = GetSubsystem<UI>();

    Graphics* graphics = GetSubsystem<Graphics>();
    Camera *camera = _cameraNode->GetComponent<Camera>();
    Ray cameraRay = camera->GetScreenRay(0.5f, 0.5f);
    // Pick only geometry objects, not eg. zones or lights, only get the first (closest) hit
    PODVector<RayQueryResult> results;
    RayOctreeQuery query(results, cameraRay, RAY_TRIANGLE, 1000, DRAWABLE_GEOMETRY);
    _sceneNode->GetComponent<Octree>()->RaycastSingle(query);
    if (results.Size())
    {
        RayQueryResult& result = results[0];
        hitPos = result.position_;
        hitDrawable = result.drawable_;
        return true;
    }

    return false;

}

Dont know if this helps: I use a dual node system: one node is the target, it is the one that gets rotations and displacements. The second is a child node with the camera, every time I update the first node, I use LookAt to keep the camera facing the target node. Perhaps the target node it is not exactly at the center of the screen, but it is almost there. I see you have better math knowledge than I, maybe you can refine my method and find the correct center point.

I still can not understand, how to rotate camera around current viewport center

  1. setup in editor with adding rollNode

roll node has idenity transforms!

  1. setup code
		playerNode = scene_->GetChild("player", true);
		playerRigidbody = playerNode->GetComponent<RigidBody>();
		camera.node = playerNode->GetChild("camera", true);
		camera.rollNode = playerNode->GetChild("roll", true);
		camera.component = camera.rollNode->GetComponent<Camera>();
		camera.viewport = new Viewport(context_, scene_, camera.component);
  1. mouse update fix (roll camera by middle mouse)
	void MoveCamera(float timeStep)
	{
		Input* input = GetSubsystem<Input>();
		const float MOUSE_SENSITIVITY = 0.1f;
		IntVector2 mouseMove = input->GetMouseMove();

		if (input->GetMouseButtonDown(2)) {
			Quaternion q = camera.rollNode->GetRotation(); // get local rotation in space of parent camera node

			// q_new = q_old * q_delta // quaternion angle add by multiply 
			camera.rollNode->SetRotation(q * Quaternion(0, 0, MOUSE_SENSITIVITY * mouseMove.x_));
		}
		else 
		{
			camera.yaw_ += MOUSE_SENSITIVITY * mouseMove.x_;
			camera.pitch_ += MOUSE_SENSITIVITY * mouseMove.y_;
			camera.pitch_ = Clamp(camera.pitch_, -90.0f, 90.0f);
		}

		camera.node->SetWorldRotation(Quaternion(camera.pitch_, camera.yaw_, 0.0f));

	}

I have created node with camera coordinates(0,20,-30) and its child roll node with coordinates (0,0,0). And added camera component to roll node.

But when I activated yaw and pitch related code, camera just shakes at same place. When I disabled it and retain only roll related, camera was rotated around local Z axis.

try to add in Start() proc

But you are not using roll_ variable in your code. I have removed _yaw and _pitch nullification at the end of any update cycle, camera stops shake, but simply don’t move

Yes. i’m calculate new roll and put it directly in method, but other variables also need to setup with zero.

but simply don’t move
you mean don’t move like - walk or run, or you mean rotation move ?
if you want somekind of walk-move you need to move or translate playerNode in case of my example.
i’m move playerNode by set velocity for rigidbody on keys.

[quote=“codingmonkey”]Yes. i’m calculate new roll and put it directly in method, but other variables also need to setup with zero.

but simply don’t move
you mean don’t move like - walk or run, or you mean rotation move ?
if you want somekind of walk-move you need to move or translate playerNode in case of my example.
i’m move playerNode by set velocity for rigidbody on keys.[/quote]

No rotation applied to camera. In the evening I will post my complete code. But previous version (with raycast) works well if ray can intersect some geometry. Maybe I have to just create default point on this ray if raycast fails.

Now it works well: I have created camera node with (0, 20, -30) position with camera component, and child node with reverse position: (0,20,-30) - this is local center node.

[code]#include “LevelCamera.h”

#include “UI.h”
#include “Input.h”
#include “Ray.h”
#include “Graphics.h”
#include “OctreeQuery.h”
#include “Octree.h”
#include “Scene.h”
#include “Log.h”

LevelCamera::LevelCamera(Context *context) :Object(context)
{

}

void LevelCamera::VerticalTranslate(float amount)
{
float currentRot = _cameraNode->GetRotation().YawAngle();
Quaternion distilledRot;
distilledRot.FromAngleAxis(currentRot, Vector3(0,1,0));
Vector3 rotated = distilledRot.RotationMatrix() * Vector3(0,0,amount);
_cameraNode->Translate(rotated, TS_WORLD);
_centerPosition->Translate(rotated);
}

void LevelCamera::HorizontalTranslate(float amount)
{
float currentRot = _cameraNode->GetRotation().YawAngle();
Quaternion distilledRot;
distilledRot.FromAngleAxis(currentRot, Vector3(0,1,0));
Vector3 rotated = distilledRot.RotationMatrix() * Vector3(amount,0,0);
_cameraNode->Translate(rotated, TS_WORLD);
_centerPosition->Translate(rotated);
}

void LevelCamera::Update()
{
UI* ui = GetSubsystem();
Input* input = GetSubsystem();
Graphics *graphics = GetSubsystem();

if (ui->GetFocusElement())
    return;

if(input->GetMousePosition().y_ < BORDER_OFFSET)
    VerticalTranslate(CAMERA_VELOCITY);
if(input->GetMousePosition().y_ >  graphics->GetHeight() - BORDER_OFFSET)
    VerticalTranslate(-CAMERA_VELOCITY);
if(input->GetMousePosition().x_ < BORDER_OFFSET)
    HorizontalTranslate(-CAMERA_VELOCITY);
if(input->GetMousePosition().x_ >  graphics->GetWidth() - BORDER_OFFSET)
    HorizontalTranslate(CAMERA_VELOCITY);
if (input->GetMouseButtonDown(MOUSEB_RIGHT))
{
    IntVector2 mouseMove = input->GetMouseMove();
    _yaw += MOUSE_SENSITIVITY * mouseMove.x_;
    _pitch += MOUSE_SENSITIVITY * mouseMove.y_;

    Vector3 centerPos = _centerPosition->GetPosition();
    _cameraNode->RotateAround(centerPos, Quaternion(_yaw, Vector3(0,1,0)), TS_WORLD);
    if(abs((int)_pitch) < 20 )
    {
        if(_cameraNode->GetRotation().PitchAngle() < 65 &&  _pitch < 0)
            _cameraNode->RotateAround(centerPos, Quaternion(_pitch, _cameraNode->GetDirection().CrossProduct(Vector3(0,1,0))), TS_WORLD);
        if(_cameraNode->GetRotation().PitchAngle() > 30 && _pitch > 0)
            _cameraNode->RotateAround(centerPos, Quaternion(_pitch, _cameraNode->GetDirection().CrossProduct(Vector3(0,1,0))), TS_WORLD);
    }

    _yaw = 0;
    _pitch = 0;
}
int wheelMove = input->GetMouseMoveWheel();
if( wheelMove != 0 && abs((int)wheelMove) < 2)
{
    Camera *camera = _cameraNode->GetComponent<Camera>();
    float oldZoom = camera->GetZoom();
    if(oldZoom > 0.5f && wheelMove < 0)
        camera->SetZoom(oldZoom + wheelMove*WHEEL_SENSITIVITY);
    if(oldZoom < 4 && wheelMove > 0)
        camera->SetZoom(oldZoom + wheelMove*WHEEL_SENSITIVITY);
}

}

void LevelCamera::Setup(Node *cameraNode, Node *centerNode, Scene *scene)
{
_sceneNode = scene;
_cameraNode = cameraNode;
_centerPosition = centerNode;

cameraNode->LookAt(_centerPosition->GetPosition());

}
[/code]