Dynamically relocate LoD vertices to enhance details

assets/voxygen/shaders/include/lod.glsl

@@ -21,23 +21,11 @@ vec2 splay(vec2 pos, float e) {
 }
 
 float splay_scale(vec2 pos, float e) {
-	return distance(splay(pos, e), splay(pos + 0.001, e)) * 5000000.0;
-}
-
-vec3 lod_pos(vec2 v_pos) {
-	vec2 hpos = focus_pos.xy + splay(v_pos, 8.0) * 1000000.0;
-	float splay = splay_scale(v_pos, 8.0) * 1.0;
-	return vec3(hpos, (
-		alt_at(hpos) +
-		alt_at(hpos + vec2(-1, 1) * splay) +
-		alt_at(hpos + vec2(1, 1) * splay) +
-		alt_at(hpos + vec2(1, -1) * splay) +
-		alt_at(hpos + vec2(-1, -1) * splay)
-	) / 5.0);
+	return distance(splay(pos, e), splay(pos + 0.001, e)) * 1000000.0;
 }
 
 vec3 lod_norm(vec2 pos) {
-	const float SAMPLE_W = 8;
+	const float SAMPLE_W = 16;
 
 	float altx0 = alt_at(pos + vec2(-1, 0) * SAMPLE_W);
 	float altx1 = alt_at(pos + vec2(1, 0) * SAMPLE_W);
@@ -52,10 +40,23 @@ vec3 lod_norm(vec2 pos) {
 	));
 }
 
+vec3 lod_pos(vec2 v_pos, vec2 focus_pos) {
+	vec2 hpos = focus_pos.xy + splay(v_pos, 4.0) * 1000000.0;
+
+	// Remove spiking by "pushing" vertices towards local optima
+	vec2 nhpos = hpos;
+	for (int i = 0; i < 5; i ++) {
+		nhpos -= lod_norm(hpos).xy * 5.0;
+	}
+	hpos = nhpos;
+
+	return vec3(hpos, alt_at(hpos));
+}
+
 vec3 lod_col(vec2 pos) {
-	//return vec3(1);
-	return texture(t_map, pos_to_uv(pos)).rgb
-		+ (texture(t_noise, pos * 0.04 + texture(t_noise, pos * 0.005).xy * 2.0 + texture(t_noise, pos * 0.06).xy * 0.6).x - 0.5) * 0.1;
+	//return vec3(0, 1, 0);
+	return texture(t_map, pos_to_uv(pos)).rgb;
+		//+ (texture(t_noise, pos * 0.04 + texture(t_noise, pos * 0.005).xy * 2.0 + texture(t_noise, pos * 0.06).xy * 0.6).x - 0.5) * 0.1;
 
 	vec3 warmth = mix(
 		vec3(0.05, 0.4, 0.1),

assets/voxygen/shaders/lod-terrain-vert.glsl

@@ -16,7 +16,7 @@ out vec3 f_norm;
 out float f_light;
 
 void main() {
-	f_pos = lod_pos(v_pos);
+	f_pos = lod_pos(v_pos, focus_pos.xy);
 
 	f_norm = lod_norm(f_pos.xy);