Why are my billboarded quads being rendered this way?

[kicknbritt]

So I am instancing a quad a bunch of times in an area in love, which seems to be going fine, but when I add some shader code to billboard them they render at an odd spot and look like they are all pivoting around (0, 0, 0) (the position of the mesh I am instancing many times).
They also rotate with the camera as well.
Do I maybe have to make a new matrix for each instance to get them all to face the camera from their position, or I am doing something else wrong?

Here is the vertex shader code for the regular, non-billboard version:

Code: Select all

mat4 ModelView = viewMatrix*modelMatrix;
            
relativeWorldPosition = projectionMatrix * ModelView * (vertexPosition + vec4(instancePositions[love_InstanceID].xyz, 0));          
            
return relativeWorldPosition;

Here is the vertex shader code for the billboard version:

Code: Select all

mat4 ModelView = viewMatrix*modelMatrix;
            
ModelView[0][0] = 1;
ModelView[0][1] = 0;
ModelView[0][2] = 0;

            // Column 1:
ModelView[1][0] = 0;
ModelView[1][1] = 1;
ModelView[1][2] = 0;

            // Column 2:
ModelView[2][0] = 0;
ModelView[2][1] = 0;
ModelView[2][2] = 1;

relativeWorldPosition = projectionMatrix * ModelView * (vertexPosition + vec4(instancePositions[love_InstanceID].xyz, 0));
            
            
return relativeWorldPosition;