aggregate1166877 · November 27, 2024 21:32 · Jan 6, 2020 · Jan 6, 2020 · Dec 22, 2019 · Dec 22, 2019
diff --git a/GodotCleanFisheyeBarrelDistortion.shader b/GodotCleanFisheyeBarrelDistortion.shader
@@ -58,7 +58,6 @@ void fragment(){
 	}
 	else {
 		COLOR.a = 0.0;
-		xy = UV;
 	}
 
 	// Apply manual crop.

diff --git a/GodotCleanFisheyeBarrelDistortion.shader b/GodotCleanFisheyeBarrelDistortion.shader
@@ -22,10 +22,11 @@
 shader_type canvas_item;
 
 // Inspector params:
-uniform float effect = -1.1; // -1.0 is BARREL, 0.1 is PINCUSHION.
+uniform float effect = -1.1; // -1.0 is BARREL, 0.1 is PINCUSHION. For planets, ideally -1.1 to -4.
 uniform float effect_scale = 1.1; // Play with this to slightly vary the results.
-uniform bool apply_crop = false; // Cut out the junk outside the sphere.
-uniform float crop_multiplier = 1.2; // Higher value = more crop.
+uniform bool dynamic_crop = false; // Guesses the crop amount with an admittedly badly inaccurate formula.
+uniform bool manual_crop = false; // Cut out the junk outside the sphere.
+uniform float manual_amount = 0.95; // Higher value = more crop.
 
 vec2 distort(vec2 p) {
 	float d = length(p);
@@ -41,18 +42,27 @@ void fragment(){
 	xy.x = xy.x - 1.0;
 	xy.y = xy.y - 1.0;
 
+	// Dynamic crop adjustment. -0.5 is equavalent to 'none'.
+	float d_adjust = -0.5;
+	if (dynamic_crop) {
+		d_adjust = (effect/4.0) * -0.6;
+	}
+
+	// Perform distortion if needed.
+	vec4 tex;
 	float d = length(xy);
-	if (d < 1.5) {
+	if (d < 1.0 - d_adjust) {
 		xy = distort(xy);
+		tex = texture(TEXTURE, xy);
+		COLOR = tex;
 	}
-	else{
+	else {
+		COLOR.a = 0.0;
 		xy = UV;
 	}
-
-	vec4 tex = texture(TEXTURE, xy);
-	if (apply_crop && d > (effect_scale / crop_multiplier)) {
-		tex.a = 0.0;
-	}
 
-	COLOR = tex;
+	// Apply manual crop.
+	if (manual_crop && d > manual_amount) {
+		COLOR.a = 0.0;
+	}
 }
diff --git a/GodotCleanFisheyeBarrelDistortion.shader b/GodotCleanFisheyeBarrelDistortion.shader
@@ -14,6 +14,9 @@
  *
  * See the final result in the edited part of my SO question:
  * https://computergraphics.stackexchange.com/questions/9434/shader-or-formula-that-distorts-inward
+ *
+ * License: CC0
+ * https://creativecommons.org/publicdomain/zero/1.0/
  */
 
 shader_type canvas_item;

diff --git a/GodotCleanFisheyeBarrelDistortion.shader b/GodotCleanFisheyeBarrelDistortion.shader
@@ -25,31 +25,28 @@ uniform bool apply_crop = false; // Cut out the junk outside the sphere.
 uniform float crop_multiplier = 1.2; // Higher value = more crop.
 
 vec2 distort(vec2 p) {
-    float d = length(p);
-    float z = sqrt(1.0 + d * d * effect);
-    float r = atan(d, z) / 3.14159;
-    r *= effect_scale;
-    float phi = atan(p.y, p.x);
-
+	float d = length(p);
+	float z = sqrt(1.0 + d * d * effect);
+	float r = atan(d, z) / 3.14159;
+	r *= effect_scale;
+	float phi = atan(p.y, p.x);
 	return vec2(r*cos(phi)+.5,r*sin(phi)+.5);
 }
 
 void fragment(){
 	vec2 xy = (2.0 * UV);
-
 	xy.x = xy.x - 1.0;
 	xy.y = xy.y - 1.0;
 
 	float d = length(xy);
-	if (d < 1.5){
+	if (d < 1.5) {
 		xy = distort(xy);
 	}
 	else{
 		xy = UV;
 	}
 
 	vec4 tex = texture(TEXTURE, xy);
-
 	if (apply_crop && d > (effect_scale / crop_multiplier)) {
 		tex.a = 0.0;
 	}

diff --git a/CleanFisheyeBarrelDistortion.shader → GodotCleanFisheyeBarrelDistortion.shader b/CleanFisheyeBarrelDistortion.shader → GodotCleanFisheyeBarrelDistortion.shader
diff --git a/CleanFisheyeBarrelDistortion.shader b/CleanFisheyeBarrelDistortion.shader
@@ -0,0 +1,58 @@
+/**
+ * This shader creates fisheye or barrel distortion by sliding values in the
+ * desired direction. It aims to have a minimal amount of pixelation, and was
+ * originally conceived of to procedurally generate cartoon planets and bodies
+ * from easily generatable flat textures.
+ *
+ * Thanks to user Dan (6145) on Stack Overflow for providing the math. I also
+ * stole some code from here for the texture placement:
+ * https://gist.github.com/quiglemj/971f4cec1b128c58b4864c5200bfc579
+ * This shader differs from the above gist in that it does not stretch the
+ * center towards the edges, but rather crushes the edges in towards the
+ * center, and thus eliminates pixelation entirely while achieving a near
+ * identical effect.
+ *
+ * See the final result in the edited part of my SO question:
+ * https://computergraphics.stackexchange.com/questions/9434/shader-or-formula-that-distorts-inward
+ */
+
+shader_type canvas_item;
+
+// Inspector params:
+uniform float effect = -1.1; // -1.0 is BARREL, 0.1 is PINCUSHION.
+uniform float effect_scale = 1.1; // Play with this to slightly vary the results.
+uniform bool apply_crop = false; // Cut out the junk outside the sphere.
+uniform float crop_multiplier = 1.2; // Higher value = more crop.
+
+vec2 distort(vec2 p) {
+    float d = length(p);
+    float z = sqrt(1.0 + d * d * effect);
+    float r = atan(d, z) / 3.14159;
+    r *= effect_scale;
+    float phi = atan(p.y, p.x);
+
+	return vec2(r*cos(phi)+.5,r*sin(phi)+.5);
+}
+
+void fragment(){
+	vec2 xy = (2.0 * UV);
+
+	xy.x = xy.x - 1.0;
+	xy.y = xy.y - 1.0;
+
+	float d = length(xy);
+	if (d < 1.5){
+		xy = distort(xy);
+	}
+	else{
+		xy = UV;
+	}
+
+	vec4 tex = texture(TEXTURE, xy);
+
+	if (apply_crop && d > (effect_scale / crop_multiplier)) {
+		tex.a = 0.0;
+	}
+
+	COLOR = tex;
+}
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