0
\$\begingroup\$

I am using modern OpenGL with glfw. I made a FPS camera with mouse and it works very well. But I want to move my mouse like Blender's model view mode. When I press the middle mouse button and move the mouse, it should move the camera. I tried it but I couldn't succeed it. I just want it like Blender.

That is my camera class (sorry for indentation):

#pragma once
#include <vector>
#include <GL/glew.h>
#include <glm/glm.hpp>
#include <glm/gtc/matrix_transform.hpp>

enum Camera_Movement {
    FORWARD,
    BACKWARD,
    LEFT,
    RIGHT
};

const GLfloat YAW        = -90.0f;
const GLfloat PITCH      =  0.0f;
const GLfloat SPEED      =  3.0f;
const GLfloat SENSITIVTY =  0.05f;
const GLfloat ZOOM       =  45.0f;



class Camera
{
public:

glm::vec3 Position;
glm::vec3 Front;
glm::vec3 Up;
glm::vec3 Right;
glm::vec3 WorldUp;

GLfloat Yaw;
GLfloat Pitch;

GLfloat MovementSpeed;
GLfloat MouseSensitivity;
GLfloat Zoom;

Camera(glm::vec3 position = glm::vec3(0.0f, 0.0f, 0.0f), glm::vec3 up =            glm::vec3(0.0f, 1.0f, 0.0f), GLfloat yaw = YAW, GLfloat pitch = PITCH) : Front(glm::vec3(0.0f, 0.0f, -1.0f)), MovementSpeed(SPEED), MouseSensitivity(SENSITIVTY), Zoom(ZOOM)
{
    this->Position = position;
    this->WorldUp = up;
    this->Yaw = yaw;
    this->Pitch = pitch;
    this->updateCameraVectors();
}
Camera(GLfloat posX, GLfloat posY, GLfloat posZ, GLfloat upX, GLfloat  upY, GLfloat upZ, GLfloat yaw, GLfloat pitch) : Front(glm::vec3(0.0f, 0.0f, -1.0f)), MovementSpeed(SPEED), MouseSensitivity(SENSITIVTY), Zoom(ZOOM)
{
    this->Position = glm::vec3(posX, posY, posZ);
    this->WorldUp = glm::vec3(upX, upY, upZ);
    this->Yaw = yaw;
    this->Pitch = pitch;
    this->updateCameraVectors();
}

glm::mat4 GetViewMatrix()
{
    return glm::lookAt(this->Position, this->Position + this->Front,  this->Up);
}

void ProcessKeyboard(Camera_Movement direction, GLfloat deltaTime)
{
    GLfloat velocity = this->MovementSpeed * deltaTime;
    if (direction == FORWARD)
        this->Position += this->Front * velocity;
    if (direction == BACKWARD)
        this->Position -= this->Front * velocity;
    if (direction == LEFT)
        this->Position -= this->Right * velocity;
    if (direction == RIGHT)
        this->Position += this->Right * velocity;
}

void ProcessMouseMovement(GLfloat xoffset, GLfloat yoffset, GLboolean  constrainPitch = true)
{
    xoffset *= this->MouseSensitivity;
    yoffset *= this->MouseSensitivity;

    this->Yaw   += xoffset;
    this->Pitch += yoffset;

    if (constrainPitch)
    {
        if (this->Pitch > 89.0f)
            this->Pitch = 89.0f;
        if (this->Pitch < -89.0f)
            this->Pitch = -89.0f;
    }

    this->updateCameraVectors();
}

void ProcessMouseScroll(GLfloat yoffset)
{
    if (this->Zoom >= 1.0f && this->Zoom <= 45.0f)
        this->Zoom -= yoffset;
    if (this->Zoom <= 1.0f)
        this->Zoom = 1.0f;
    if (this->Zoom >= 45.0f)
        this->Zoom = 45.0f;
}

private:
void updateCameraVectors()
{
    glm::vec3 front;
    front.x = cos(glm::radians(this->Yaw)) * cos(glm::radians(this-  >Pitch));
    front.y = sin(glm::radians(this->Pitch));
    front.z = sin(glm::radians(this->Yaw)) * cos(glm::radians(this->Pitch));
    this->Front = glm::normalize(front);
    this->Right = glm::normalize(glm::cross(this->Front, this->WorldUp));
    this->Up    = glm::normalize(glm::cross(this->Right, this->Front));
}
};

Thank you.

\$\endgroup\$
0
\$\begingroup\$

First check if the middle mouse button is down, then get the movement of the mouse and convert it to a vector (to a vec3, where x is the movement on the x axis, y is the movement on the y axis and z is 0.

With glm create a rotation matrix using your camera's angles:

glm::mat4 rotPitch = glm::rotate(this->Pitch, glm::vec3(1, 0, 0));
glm::mat4 rotYaw = glm::rotate(this->Yaw, glm::vec3(0, 1, 0));
glm::mat4 rot = rotPitch * rotYaw;

Then multiply your movement vector with this matrix (you need to convert it to a 4d vector):

glm::vec3 transform = vec3(rot * glm::vec4(movement, 0));

Add this vector to the position of the camera and done

\$\endgroup\$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.