I’m working on a simple billboard shader that always faces the camera but maintains pitch. If the camera rotates up around the x axis, the billboard will shrink as if looking down on an actual billboard. I can’t seem to get the latter to work.
Here is my vertex shader:
uniform mat4 mProjection;
uniform mat4 mView;
uniform mat4 mModel;
varying vec4 textureCoords;
void main(void)
{
gl_TexCoord[0] = gl_MultiTexCoord0;
mat4 temp = mView*mModel;
temp[0][0] = 1;
temp[0][1] = 0;
temp[0][2] = 0;
temp[1][0] = 0;
temp[1][1] = 1;
temp[1][2] = 0;
temp[2][0] = 0;
temp[2][1] = 0;
temp[2][2] = 1;
gl_Position = mProjection * temp * gl_Vertex;
textureCoords = vec4(gl_Vertex.x + 0.5, gl_Vertex.y + 0.5, 0.0, 0.0);
}
I tried importing the pitch (in radians) as a uniform in an attempt to rotate the object back along the x but could not get it to work.
Anyone have any suggestions?