calculate displacement offset directly in buffer

Author: Xtarsia

src/shaders/displacement.glsl

@@ -16,15 +16,12 @@ vec3 get_displacement(vec2 pos, float scale) {
 	vec2 d_uv = (pos - round(_target_pos.xz * _vertex_density * scale) / scale) / (_mesh_size * 2.0 / scale) + 0.5;
 	d_uv.x += s - 1.;
 	d_uv.x /= log2(_subdiv);
-	highp vec3 nrm_h = vec3(0.);
+	highp vec3 disp = vec3(0.);
 	if (all(greaterThanEqual(d_uv, vec2(0.0))) && all(lessThanEqual(d_uv, vec2(1.0)))) {
-		nrm_h = textureLod(_displacement_buffer, d_uv, 0.).rgb;
-		float height = nrm_h.z - 0.5;
-		nrm_h.xy = fma(nrm_h.xy, vec2(2.0), vec2(-1.0));
-		nrm_h.z = sqrt(clamp(1.0 - dot(nrm_h.xy, nrm_h.xy), 0.0, 1.0));
-		nrm_h = nrm_h.xzy * height * displacement_scale;
+		disp = textureLod(_displacement_buffer, d_uv, 0.).rgb * 2.0 - 1.0;
+		disp *= displacement_scale;
 	}
-	return nrm_h;
+	return disp;
 }
 
 //INSERT: DISPLACEMENT_VERTEX

src/shaders/displacement_buffer.glsl

@@ -62,8 +62,7 @@ uniform highp sampler2DArray _control_maps : repeat_disable;
 
 // Public uniforms
 //INSERT: AUTO_SHADER_UNIFORMS
-
-uniform float height_sharpness : hint_range(0.0, 1.0, 0.01) = 0.5;
+uniform float displacement_sharpness : hint_range(0.0, 1.0, 0.01) = 0.5;
 uniform bool vertical_projection = true;
 uniform float projection_threshold : hint_range(0.0, 0.99, 0.01) = 0.8;
 
@@ -168,7 +167,7 @@ void accumulate_material(const mat3 TNB, const float weight, const ivec3 index,
 	#define FAST_WORLD_NORMAL(n) fma(TNB[0], vec3(n.x), fma(TNB[2], vec3(n.z), TNB[1] * vec3(n.y)))
 
 	float blend = DECODE_BLEND(control); // only used for branching.
-	float sharpness = fma(11., height_sharpness, 1.);
+	float sharpness = fma(11., displacement_sharpness, 1.);
 
 	// 1st Texture Asset ID
 	if (blend < 1.0) {
@@ -370,10 +369,7 @@ void fragment() {
 	mat.albedo_height *= weight_inv;
 
 	// Output
-	// Displacement Direction Vector3 (reconstructed from XZ when used later)
-	COLOR.rg = fma(w_normal.xz, vec2(0.5), vec2(0.5));
-	// Displacement Ammount -0.5 to 0.5, stored in 0.0 - 1.0 Range
-	COLOR.b = mat.albedo_height.a;
+	COLOR.rgb = fma(w_normal * (mat.albedo_height.a - 0.5), vec3(0.5), vec3(0.5));
 
 }
 )"