Have separate notions of gloss and reflectiveness

manimlib/mobject/mobject.py

@@ -43,10 +43,13 @@ class Mobject(object):
         "opacity": 1,
         "dim": 3,  # TODO, get rid of this
         # Lighting parameters
-        # Positive gloss up to 1 makes it reflect the light.
-        "gloss": 0.0,
-        # Positive shadow up to 1 makes a side opposite the light darker
+        # ...
+        # Larger reflectiveness makes things brighter when facing the light
+        "reflectiveness": 0.0,
+        # Larger shadow makes faces opposite the light darker
         "shadow": 0.0,
+        # Makes parts bright where light gets reflected toward the camera
+        "gloss": 0.0,
         # For shaders
         "shader_folder": "",
         "render_primitive": moderngl.TRIANGLE_STRIP,
@@ -82,11 +85,11 @@ class Mobject(object):
     def __str__(self):
         return self.__class__.__name__
 
-    def __add__(self, other : 'Mobject') -> 'Mobject':
+    def __add__(self, other: 'Mobject') -> 'Mobject':
         assert(isinstance(other, Mobject))
         return self.get_group_class()(self, other)
 
-    def __mul__(self, other : 'int') -> 'Mobject':
+    def __mul__(self, other: 'int') -> 'Mobject':
         assert(isinstance(other, int))
         return self.replicate(other)
 
@@ -102,6 +105,7 @@ class Mobject(object):
             "is_fixed_in_frame": float(self.is_fixed_in_frame),
             "gloss": self.gloss,
             "shadow": self.shadow,
+            "reflectiveness": self.reflectiveness,
         }
 
     def init_colors(self):
@@ -394,6 +398,7 @@ class Mobject(object):
             self.submobjects.sort(key=submob_func)
         else:
             self.submobjects.sort(key=lambda m: point_to_num_func(m.get_center()))
+        self.assemble_family()
         return self
 
     def shuffle(self, recurse=False):
@@ -401,6 +406,7 @@ class Mobject(object):
             for submob in self.submobjects:
                 submob.shuffle(recurse=True)
         random.shuffle(self.submobjects)
+        self.assemble_family()
         return self
 
     # Copying
@@ -974,12 +980,12 @@ class Mobject(object):
     def fade(self, darkness=0.5, recurse=True):
         self.set_opacity(1.0 - darkness, recurse=recurse)
 
-    def get_gloss(self):
-        return self.uniforms["gloss"]
+    def get_reflectiveness(self):
+        return self.uniforms["reflectiveness"]
 
-    def set_gloss(self, gloss, recurse=True):
+    def set_reflectiveness(self, reflectiveness, recurse=True):
         for mob in self.get_family(recurse):
-            mob.uniforms["gloss"] = gloss
+            mob.uniforms["reflectiveness"] = reflectiveness
         return self
 
     def get_shadow(self):
@@ -990,6 +996,14 @@ class Mobject(object):
             mob.uniforms["shadow"] = shadow
         return self
 
+    def get_gloss(self):
+        return self.uniforms["gloss"]
+
+    def set_gloss(self, gloss, recurse=True):
+        for mob in self.get_family(recurse):
+            mob.uniforms["gloss"] = gloss
+        return self
+
     # Background rectangle
 
     def add_background_rectangle(self, color=None, opacity=0.75, **kwargs):
@@ -1617,8 +1631,8 @@ class Group(Mobject):
             raise Exception("All submobjects must be of type Mobject")
         Mobject.__init__(self, **kwargs)
         self.add(*mobjects)
-        
-    def __add__(self, other : 'Mobject' or 'Group'):
+
+    def __add__(self, other: 'Mobject' or 'Group'):
         assert(isinstance(other, Mobject))
         return self.add(other)
 

manimlib/shaders/inserts/camera_uniform_declarations.glsl

@@ -1,6 +1,6 @@
 uniform vec2 frame_shape;
 uniform float anti_alias_width;
-uniform vec3 camera_center;
+uniform vec3 camera_offset;
 uniform mat3 camera_rotation;
 uniform float is_fixed_in_frame;
 uniform float focal_distance;

manimlib/shaders/inserts/finalize_color.glsl

@@ -13,39 +13,56 @@ vec4 add_light(vec4 color,
                vec3 point,
                vec3 unit_normal,
                vec3 light_coords,
+               vec3 cam_coords,
+               float reflectiveness,
                float gloss,
                float shadow){
-    if(gloss == 0.0 && shadow == 0.0) return color;
+    if(reflectiveness == 0.0 && gloss == 0.0 && shadow == 0.0) return color;
 
-    float camera_distance = focal_distance;
+    vec4 result = color;
     // Assume everything has already been rotated such that camera is in the z-direction
-    vec3 to_camera = vec3(0, 0, camera_distance) - point;
-    vec3 to_light = light_coords - point;
+    // cam_coords = vec3(0, 0, focal_distance);
+    vec3 to_camera = normalize(cam_coords - point);
+    vec3 to_light = normalize(light_coords - point);
 
-    // TODO, do we actually want this?  It effectively treats surfaces as two-sided
-    if(dot(to_camera,unit_normal) < 0){
-            unit_normal *= -1;
-    }
+    // Note, this effectively treats surfaces as two-sided
+    // if(dot(to_camera, unit_normal) < 0) unit_normal *= -1;
 
+    float light_to_normal = dot(to_light, unit_normal);
+    // When unit normal points towards light, brighten
+    float bright_factor = max(light_to_normal, 0) * reflectiveness;
+    // For glossy surface, add extra shine if light beam go towards camera
     vec3 light_reflection = -to_light + 2 * unit_normal * dot(to_light, unit_normal);
-    float dot_prod = dot(normalize(light_reflection), normalize(to_camera));
-    float shine = gloss * exp(-3 * pow(1 - dot_prod, 2));
-    float dp2 = dot(normalize(to_light), unit_normal);
-    float darkening = mix(1, max(dp2, 0), shadow);
-    return vec4(
-            darkening * mix(color.rgb, vec3(1.0), shine),
-            color.a
-    );
+    float light_to_cam = dot(light_reflection, to_camera);
+    float shine = gloss * exp(-3 * pow(1 - light_to_cam, 2));
+    bright_factor += shine;
+
+    result.rgb = mix(result.rgb, vec3(1.0), bright_factor);
+    if (light_to_normal < 0){
+        // Darken
+        result.rgb = mix(result.rgb, vec3(0.0), -light_to_normal * shadow);
+    }
+    // float darkening = mix(1, max(light_to_normal, 0), shadow);
+    // return vec4(
+    //     darkening * mix(color.rgb, vec3(1.0), shine),
+    //     color.a
+    // );
+    return result;
 }
 
 vec4 finalize_color(vec4 color,
                     vec3 point,
                     vec3 unit_normal,
                     vec3 light_coords,
+                    vec3 cam_coords,
+                    float reflectiveness,
                     float gloss,
                     float shadow){
     ///// INSERT COLOR FUNCTION HERE /////
     // The line above may be replaced by arbitrary code snippets, as per
     // the method Mobject.set_color_by_code
-    return add_light(color, point, unit_normal, light_coords, gloss, shadow);
+    return add_light(
+        color, point, unit_normal, light_coords, cam_coords,
+        reflectiveness, gloss, shadow
+    );
 }

manimlib/shaders/inserts/get_rotated_surface_unit_normal_vector.glsl

@@ -1,5 +1,5 @@
 // Assumes the following uniforms exist in the surrounding context:
-// uniform vec3 camera_center;
+// uniform vec3 camera_offset;
 // uniform mat3 camera_rotation;
 
 vec3 get_rotated_surface_unit_normal_vector(vec3 point, vec3 du_point, vec3 dv_point){

manimlib/shaders/inserts/position_point_into_frame.glsl

@@ -1,6 +1,6 @@
 // Assumes the following uniforms exist in the surrounding context:
 // uniform float is_fixed_in_frame;
-// uniform vec3 camera_center;
+// uniform vec3 camera_offset;
 // uniform mat3 camera_rotation;
 
 vec3 rotate_point_into_frame(vec3 point){
@@ -15,5 +15,5 @@ vec3 position_point_into_frame(vec3 point){
     if(bool(is_fixed_in_frame)){
         return point;
     }
-    return rotate_point_into_frame(point - camera_center);
+    return rotate_point_into_frame(point - camera_offset);
 }

manimlib/shaders/mandelbrot_fractal/frag.glsl

@@ -1,6 +1,8 @@
 #version 330
 
 uniform vec3 light_source_position;
+uniform vec3 camera_position;
+uniform float reflectiveness;
 uniform float gloss;
 uniform float shadow;
 uniform float focal_distance;
@@ -71,6 +73,8 @@ void main() {
         xyz_coords,
         vec3(0.0, 0.0, 1.0),
         light_source_position,
+        camera_position,
+        reflectiveness,
         gloss,
         shadow
     );

manimlib/shaders/newton_fractal/frag.glsl

@@ -1,6 +1,8 @@
 #version 330
 
 uniform vec3 light_source_position;
+uniform vec3 camera_position;
+uniform float reflectiveness;
 uniform float gloss;
 uniform float shadow;
 uniform float focal_distance;
@@ -151,6 +153,8 @@ void main() {
         xyz_coords,
         vec3(0.0, 0.0, 1.0),
         light_source_position,
+        camera_position,
+        reflectiveness,
         gloss,
         shadow
     );

manimlib/shaders/quadratic_bezier_fill/geom.glsl

@@ -11,6 +11,8 @@ uniform float focal_distance;
 uniform float is_fixed_in_frame;
 // Needed for finalize_color
 uniform vec3 light_source_position;
+uniform vec3 camera_position;
+uniform float reflectiveness;
 uniform float gloss;
 uniform float shadow;
 
@@ -44,6 +46,8 @@ void emit_vertex_wrapper(vec3 point, int index){
         point,
         v_global_unit_normal[index],
         light_source_position,
+        camera_position,
+        reflectiveness,
         gloss,
         shadow
     );

manimlib/shaders/quadratic_bezier_stroke/geom.glsl

@@ -13,7 +13,9 @@ uniform float flat_stroke;
 
 //Needed for lighting
 uniform vec3 light_source_position;
+uniform vec3 camera_position;
 uniform float joint_type;
+uniform float reflectiveness;
 uniform float gloss;
 uniform float shadow;
 
@@ -259,6 +261,8 @@ void main() {
             xyz_coords,
             v_global_unit_normal[index_map[i]],
             light_source_position,
+            camera_position,
+            reflectiveness,
             gloss,
             shadow
         );

manimlib/shaders/surface/frag.glsl

@@ -1,6 +1,8 @@
 #version 330
 
 uniform vec3 light_source_position;
+uniform vec3 camera_position;
+uniform float reflectiveness;
 uniform float gloss;
 uniform float shadow;
 uniform float focal_distance;
@@ -19,6 +21,8 @@ void main() {
         xyz_coords,
         normalize(v_normal),
         light_source_position,
+        camera_position,
+        reflectiveness,
         gloss,
         shadow
     );

manimlib/shaders/textured_surface/frag.glsl

@@ -4,6 +4,8 @@ uniform sampler2D LightTexture;
 uniform sampler2D DarkTexture;
 uniform float num_textures;
 uniform vec3 light_source_position;
+uniform vec3 camera_position;
+uniform float reflectiveness;
 uniform float gloss;
 uniform float shadow;
 uniform float focal_distance;
@@ -36,6 +38,8 @@ void main() {
         xyz_coords,
         normalize(v_normal),
         light_source_position,
+        camera_position,
+        reflectiveness,
         gloss,
         shadow
     );

manimlib/shaders/true_dot/frag.glsl

@@ -1,10 +1,13 @@
 #version 330
 
 uniform vec3 light_source_position;
+uniform vec3 camera_position;
+uniform float reflectiveness;
 uniform float gloss;
 uniform float shadow;
 uniform float anti_alias_width;
 uniform float focal_distance;
+uniform float glow_factor;
 
 in vec4 color;
 in float radius;
@@ -22,14 +25,23 @@ void main() {
     if (signed_dist > 0.5 * anti_alias_width){
         discard;
     }
-    vec3 normal = vec3(diff / radius, sqrt(1 - (dist * dist) / (radius * radius)));
-    frag_color = finalize_color(
-        color,
-        vec3(point.xy, 0.0),
-        normal,
-        light_source_position,
-        gloss,
-        shadow
-    );
+    frag_color = color;
+    if(gloss > 0 || shadow > 0){
+        vec3 normal = vec3(diff / radius, sqrt(1 - (dist * dist) / (radius * radius)));
+        frag_color = finalize_color(
+            frag_color,
+            vec3(point.xy, 0.0),
+            normal,
+            light_source_position,
+            camera_position,
+            reflectiveness,
+            gloss,
+            shadow
+        );
+    }
+    if(glow_factor > 0){
+        frag_color.a *= pow(1 - dist / radius, glow_factor);
+    }
+
     frag_color.a *= smoothstep(0.5, -0.5, signed_dist / anti_alias_width);
 }