#version 3.8;
global_settings {assumed_gamma 1.0}

#declare CameraLocation = <-50, 10, -40>;
#declare CameraLookAt = <0, 0, 0>;

camera {
	location CameraLocation
	right x*image_width/image_height
	up y
	look_at CameraLookAt
}

light_source {<50, 50, -100> rgb 1}

sky_sphere {pigment {rgb <0.3, 0.3, 0.75>}}

#macro Axes (Extent, Linewidth, BothSigns)
	sphere {0, Linewidth*2 texture {pigment {rgb 1} finish {emission 1}}}
	#local Cardinal = array [3] {x, y, z}
	#for (A, 0, 2)
		cylinder {-Cardinal[A]*Extent*BothSigns, Cardinal[A]*Extent Linewidth texture {pigment {rgb Cardinal[A]} finish {emission 1}} }
	#end
#end // end macro Axes


Axes (100, 0.125, no)

#macro FaceCamera (Object, CL)
	#local Min = min_extent (Object);
	#local Max = max_extent (Object);
	#local OL = Min + (Max-Min)/2;
	
	#declare CamL = CameraLocation;				// wherever you're putting it
	//#declare CamD = vnormalize(CameraLookAt-CamL);	// direction of camera view
	#declare CamD = vnormalize(OL-CamL);			// direction of camera view
	#declare CamR = vnormalize(vcross(y,CamD));		// to the right
	#declare CamU = vnormalize(vcross(CamD,CamR));	// camera up
	#declare Object_Transform =
	transform {
		matrix <
		CamR.x, CamR.y, CamR.z,
		CamU.x, CamU.y, CamU.z,
		CamD.x, CamD.y, CamD.z,
		    0,      0,      0
		>
	}
	
	object {
		Object
		transform {Object_Transform}
	}
#end // end macro FaceCamera

#declare MyObject = 
text { ttf "arial.ttf", "Text always faces the camera.", 0.05, 0.0
       texture {pigment {rgb z}}
       scale 1
       translate y*5
       translate x*3
       translate <0, 0, -20>
}



FaceCamera (MyObject, CameraLocation)