Billboarding

glm::mat4 billboardMVMatrix(glm::mat4 mvmatrix, glm::vec3 scale) {
    // Column 0:
    mvmatrix[0][0] = scale[0];
    mvmatrix[0][1] = 0;
    mvmatrix[0][2] = 0;

    // Column 1:
    mvmatrix[1][0] = 0;
    mvmatrix[1][1] = scale[1];
    mvmatrix[1][2] = 0;

    // Column 2:
    mvmatrix[2][0] = 0;
    mvmatrix[2][1] = 0;
    mvmatrix[2][2] = scale[2];

    return mvmatrix;
}

glm::mat4 tmp = ss->m_activeCamera->getVM() * spark->m_modelMatrix;
uniform = glGetUniformLocation(ss->m_activeShader->m_programObject, "MVMatrix");
glUniformMatrix4fv(uniform, 1, GL_FALSE, (float*)&(this->billboardMVMatrix(tmp, spark->scale))[0]);

// Shader
#version 330 core //compatibility

layout(location = 0) in vec3 VertexPosition;
// layout(location = 1) in vec3 VertexNormal;
layout(location = 2) in vec2 VertexTex;

uniform mat4 PMatrix;       //Camera projection matrix
uniform mat4 MVMatrix;      //VMatrix * Model matrix

out vec2 textureCoords;

void main()
{
    gl_Position = PMatrix * MVMatrix * vec4(VertexPosition, 1.0);
    textureCoords = VertexTex.xy;

}