EDIT amelioration du shader de terrain.

assets/decors/terrains/demo/terrain.shader

@@ -1,20 +1,29 @@
 shader_type spatial;
 render_mode blend_mix,depth_draw_opaque,cull_back,diffuse_burley,specular_schlick_ggx;
 uniform vec4 albedo : hint_color;
-uniform sampler2D texture_albedo : hint_albedo;
-uniform sampler2D texture_grass_2 : hint_albedo;
-uniform sampler2D texture_albedo_2 : hint_albedo;
-uniform sampler2D texture_albedo_hsv : hint_white;
+uniform sampler2D texture_grass : hint_albedo;
+uniform sampler2D texture_grass_height : hint_white;
+uniform sampler2D texture_dirt : hint_albedo;
+uniform sampler2D texture_dirt_height : hint_black;
+uniform sampler2D texture_hsv_mask : hint_white;
+uniform sampler2D texture_hsv2_mask : hint_white;
 uniform sampler2D texture_albedo_mix : hint_black;
+uniform sampler2D texture_mix_gradiant : hint_black;
+uniform sampler2D texture_mix_border : hint_black;
+
+uniform sampler2D texture_albedo_mix2 : hint_black;
 uniform float specular;
 uniform float metallic;
 uniform float roughness : hint_range(0,1);
 uniform float point_size : hint_range(0,128);
 uniform sampler2D texture_roughness : hint_white;
+uniform sampler2D texture_roughness_dirt : hint_white;
 uniform vec4 roughness_texture_channel;
 uniform sampler2D texture_normal : hint_normal;
+uniform sampler2D texture_normal_dirt : hint_normal;
 uniform float normal_scale : hint_range(-16,16);
 uniform sampler2D texture_ambient_occlusion : hint_white;
+uniform sampler2D texture_ambient_occlusion_dirt : hint_white;
 uniform vec4 ao_texture_channel;
 uniform float ao_light_affect;
 uniform vec3 uv1_scale;
@@ -24,13 +33,12 @@ uniform vec3 uv2_offset;
 
 uniform vec3 hsv;
 uniform float grass_level = 1.0;
+uniform float angle = 0.0;
 
 varying vec2 base_uv;
 varying vec2 rotated_uv;
 varying vec2 rotated_uv_mask;
 
-
-
 vec2 rotateUVmatrinx(vec2 uv, vec2 pivot, float rotation)
 {
     mat2 rotation_matrix=mat2(  vec2(sin(rotation),-cos(rotation)),
@@ -71,44 +79,91 @@ vec3 hsv2rgb(vec3 c)
     return c.z * mix(K.xxx, clamp(p - K.xxx, 0.0, 1.0), c.y);
 }
 
-void vertex() {
+
+
+void vertex() 
+{
 	base_uv=UV*uv1_scale.xy+uv1_offset.xy;
-    rotated_uv = rotateUVmatrinx(base_uv, vec2(0.5), (VERTEX.x));
-    rotated_uv = base_uv;
-    rotated_uv_mask = rotateUVmatrinx(UV, vec2(0.5), (VERTEX.x));
-    rotated_uv_mask = UV;
+    rotated_uv = rotateUVmatrinx(base_uv, vec2(0.5), (angle));
+//    rotated_uv = base_uv;
+    rotated_uv_mask = rotateUVmatrinx(UV, vec2(0.5), (angle));
+//    rotated_uv_mask = UV;
+    
     
 }
 
 
 
 
-void fragment() {
+void fragment() 
+{
 //	vec2 base_uv = UV;
-	vec4 albedo_tex = texture(texture_albedo,rotated_uv);
-	vec4 grass_2_tex = texture(texture_grass_2,rotated_uv);
-	vec4 albedo_2_tex = texture(texture_albedo_2,rotated_uv);
-	vec4 albedo_hsv_tex = texture(texture_albedo_hsv,rotated_uv_mask);
-	vec4 albedo_mix_tex = texture(texture_albedo_mix,rotated_uv_mask);
-	ALBEDO = albedo.rgb * albedo_tex.rgb;    
-    
-//    ALBEDO = mix( ALBEDO, grass_2_tex.rgb, 0.5 );
+	vec4 grass_tex = texture(texture_grass,base_uv);
+	vec4 grass_height_tex = texture(texture_grass_height,base_uv);
+	vec4 dirt_tex = texture(texture_dirt,base_uv);
+	vec4 dirt_height_tex = texture(texture_dirt_height,base_uv);
+	vec4 dirt_height_hsv_tex = texture(texture_dirt_height,rotated_uv_mask);
+	vec4 hsv_mask_tex = texture(texture_hsv_mask,UV);
+	vec4 hsv2_mask_tex = texture(texture_hsv2_mask,UV*vec2(5.0,5.0));
+	vec4 albedo_mix_tex = texture(texture_albedo_mix,UV);
+	vec4 mix_gradiant_tex = texture(texture_mix_gradiant,vec2( albedo_mix_tex.r, albedo_mix_tex.r ));
+	vec4 albedo_mix_tex_low = texture(texture_albedo_mix,UV*vec2(5.0,5.0));
+	vec4 mix_gradiant_low_tex = texture(texture_mix_gradiant,vec2( albedo_mix_tex_low.r, albedo_mix_tex_low.r ));
+	vec4 mix_gradiant_border = texture(texture_mix_border,vec2( albedo_mix_tex_low.r, albedo_mix_tex_low.r ));
+	vec4 albedo_mix_tex2 = texture(texture_albedo_mix2,base_uv);
+	vec4 mix_gradiant2_tex = texture(texture_mix_gradiant,vec2( albedo_mix_tex2.r, albedo_mix_tex2.r ));
+	ALBEDO = albedo.rgb * grass_tex.rgb;    
     
     vec3 hsv_albedo = rgb2hsv(ALBEDO);
-    vec3 hsv_mask = rgb2hsv( albedo_hsv_tex.rgb );
-    hsv_albedo.x = hsv_mask.x;
-    hsv_albedo.y = hsv_mask.y;
-    hsv_albedo.z *= hsv_mask.z;
+    vec3 hsv_mask = rgb2hsv( hsv_mask_tex.rgb );
+    vec3 hsv2_mask = rgb2hsv( hsv2_mask_tex.rgb );
+    hsv_albedo.x *= hsv.x;
+    hsv_albedo.y = hsv.y;
+    hsv_albedo.z *= hsv.z * (hsv_mask.z * hsv2_mask.z*2.0);
     ALBEDO = hsv2rgb( hsv_albedo );
 
-    ALBEDO = mix( ALBEDO, albedo_2_tex.rgb, min( 1.0, max(-1.0, albedo_mix_tex.r-grass_level)) );
+
+     vec4 mix_mix = mix( mix_gradiant_tex, mix_gradiant2_tex, 0.5 );
+    
+    float mix_level = clamp( mix_gradiant_tex.r*mix_gradiant_border.r-grass_level, 0.0, 1.0 );
+
+//    if ( grass_height_tex.r > 0.5 )
+//    {
+////        mix_level = 0.0;    
+//    }
+//    else
+//    {
+//        mix_level = 1.0;    
+//    }
+    if ( mix_level > 0.0 && mix_level < 1.0 )
+    {
+        if ( grass_height_tex.r < dirt_height_tex.r ) 
+        {
+            mix_level = 1.0;
+        }   
+        else
+        {
+            mix_level = 0.0;    
+        }
+    }
+    mix_level *= mix_level;
+    mix_level *= mix_level;
+    mix_level *= mix_level;
+    vec3 hsv_dirt = rgb2hsv(dirt_tex.rgb);
+    vec3 hsv_dirt_height = rgb2hsv(dirt_height_hsv_tex.rgb);
+    hsv_dirt.y = hsv.y*hsv_mask.z;
+    hsv_dirt.z *= hsv.z*hsv_mask.z;
+    dirt_tex.rgb = hsv2rgb( hsv_dirt );
+    ALBEDO = mix( ALBEDO, dirt_tex.rgb, mix_level );
 
 	METALLIC = metallic;
-	float roughness_tex = dot(texture(texture_roughness,rotated_uv),roughness_texture_channel);
-	ROUGHNESS = roughness_tex * roughness;
+    vec4 final_roughness = mix( texture(texture_roughness,base_uv),texture(texture_roughness_dirt,base_uv), mix_level );
+	ROUGHNESS = dot(final_roughness, roughness_texture_channel) * roughness;
 	SPECULAR = specular;
-	NORMALMAP = texture(texture_normal,rotated_uv).rgb;
+    vec4 final_normal = mix( texture(texture_normal,base_uv), texture(texture_normal_dirt,base_uv), mix_level );
+	NORMALMAP = final_normal.rgb;
 	NORMALMAP_DEPTH = normal_scale;
-	AO = dot(texture(texture_ambient_occlusion,rotated_uv),ao_texture_channel);
-	AO_LIGHT_AFFECT = ao_light_affect;
+    vec4 final_ao = mix( texture(texture_ambient_occlusion,base_uv), texture(texture_ambient_occlusion_dirt,base_uv), mix_level );
+	AO = dot(final_ao,ao_texture_channel);
+    AO_LIGHT_AFFECT = ao_light_affect;
 }

scenes/game/game.tscn

@@ -25,8 +25,8 @@ noise = SubResource( 1 )
 [sub_resource type="ShaderMaterial" id=3]
 resource_local_to_scene = true
 shader = ExtResource( 5 )
-shader_param/iTime = 92.0443
-shader_param/iFrame = 3942
+shader_param/iTime = 3.93876
+shader_param/iFrame = 307
 shader_param/COVERAGE = 0.5
 shader_param/THICKNESS = 25.0
 shader_param/ABSORPTION = 1.031