LOD System (Tutorial Part 4)

grass-stalk-simple.mtl

@@ -0,0 +1,2 @@
+# Blender 4.4.3 MTL File: 'None'
+# www.blender.org

grass-stalk-simple.obj

@@ -0,0 +1,15 @@
+# Blender 4.4.3
+# www.blender.org
+mtllib grass-stalk-simple.mtl
+o Plane
+v -0.123385 -0.000477 0.000000
+v 0.128999 -0.000477 0.000000
+v -0.001473 1.039178 -0.000000
+vn 0.7726 0.0308 0.6342
+vn -0.0977 0.0030 0.9952
+vn -0.7726 0.0307 0.6342
+vt 0.121405 0.000035
+vt 0.056603 0.999965
+vt 0.000035 0.000035
+s 1
+f 2/1/1 3/2/2 1/3/3

grass-stalk-simple.obj.import

@@ -0,0 +1,25 @@
+[remap]
+
+importer="wavefront_obj"
+importer_version=1
+type="Mesh"
+uid="uid://c4c5i2vg0gdt"
+path="res://.godot/imported/grass-stalk-simple.obj-a57ffbc21d988749ddd9aebd794678af.mesh"
+
+[deps]
+
+files=["res://.godot/imported/grass-stalk-simple.obj-a57ffbc21d988749ddd9aebd794678af.mesh"]
+
+source_file="res://grass-stalk-simple.obj"
+dest_files=["res://.godot/imported/grass-stalk-simple.obj-a57ffbc21d988749ddd9aebd794678af.mesh", "res://.godot/imported/grass-stalk-simple.obj-a57ffbc21d988749ddd9aebd794678af.mesh"]
+
+[params]
+
+generate_tangents=true
+generate_lods=true
+generate_shadow_mesh=true
+generate_lightmap_uv2=false
+generate_lightmap_uv2_texel_size=0.2
+scale_mesh=Vector3(1, 1, 1)
+offset_mesh=Vector3(0, 0, 0)
+force_disable_mesh_compression=false

grass.gdshader

@@ -14,14 +14,16 @@ uniform float patch_scale = 5.0;
 varying float patch_factor;
 
 uniform sampler2D wind_noise;
-uniform float wind_strength = 0.1;
+uniform float wind_strength = 0.15;
 uniform vec2 wind_direction = vec2(1.0, 0.0);
 uniform float wind_bend_strength = 2.0;
-uniform float wind_ao_affect = 1.5;
+uniform float wind_ao_affect = 1.0;
 
 uniform float object_radius = 1.0;
 uniform vec3 object_position;
 
+instance uniform float alpha = 1.0;
+
 varying float bottom_to_top;
 varying float current_wind_bend;
 varying float cut_height;
@@ -29,7 +31,7 @@ varying float cut_height;
 void vertex() {
 	cut_height = 1.0;
 
-	// Cutting all grass on the right
+	//// Cutting all grass on the right
 	//if (NODE_POSITION_WORLD.x > 0.0) {
 		//cut_height = 0.5;
 //
@@ -53,14 +55,14 @@ void vertex() {
 
 	VERTEX.xz += current_wind_bend * local_direction * wind_bend_strength;
 
-	// Bend away from the object
+	//// Bend away from the object
-	float object_distance = distance(object_position, NODE_POSITION_WORLD);
+	//float object_distance = distance(object_position, NODE_POSITION_WORLD);
-	float bend_away_strength = max(object_radius - object_distance, 0.0) / object_radius;
+	//float bend_away_strength = max(object_radius - object_distance, 0.0) / object_radius;
-	vec2 bend_direction = normalize(object_position.xz - NODE_POSITION_WORLD.xz);
+	//vec2 bend_direction = normalize(object_position.xz - NODE_POSITION_WORLD.xz);
-
+//
-	VERTEX.xz -= (inv_model * vec4(bend_direction.x, 0.0, bend_direction.y, 0.0)).xz
+	//VERTEX.xz -= (inv_model * vec4(bend_direction.x, 0.0, bend_direction.y, 0.0)).xz
-			* bend_away_strength * bottom_to_top;
+			//* bend_away_strength * bottom_to_top;
-	VERTEX.y -= bend_away_strength * bottom_to_top * 0.5;
+	//VERTEX.y -= bend_away_strength * bottom_to_top * 0.5;
 
 	// General appearance
 	VERTEX.z += blade_bend * pow(bottom_to_top, 2.0);
@@ -68,19 +70,21 @@ void vertex() {
 	patch_factor = texture(patch_noise, NODE_POSITION_WORLD.xz / patch_scale).r;
 	VERTEX *= mix(size_small, size_large, patch_factor);
 
-	NORMAL = mix(NORMAL, vec3(0.0, 1.0, 0.0), bottom_to_top);
+	NORMAL = mix(NORMAL, vec3(0.0, 1.0, 0.0), mix(1.0, bottom_to_top, alpha + 0.2));
 }
 
 void fragment() {
-	// Correct normals on back-faces
 	if (!FRONT_FACING) NORMAL = -NORMAL;
-	
+
 	AO = bottom_to_top - current_wind_bend * wind_ao_affect;
-	AO_LIGHT_AFFECT = cut_height;
+	AO_LIGHT_AFFECT = mix(0.2, 1.0, alpha);
 
 	ALBEDO = mix(color_small, color_large, patch_factor);
 	BACKLIGHT = vec3(0.2);
 
 	ROUGHNESS = 0.4;
-	SPECULAR = 0.2;
+	SPECULAR = 0.12;
+	
+	ALPHA = alpha;
+	ALPHA_HASH_SCALE = 1.0;
 }

grass_chunk.gd

@@ -0,0 +1,34 @@
+@tool
+extends Node3D
+
+@export var lod_switch := 10.0
+@export var impostor_fade_in_start := 5.0
+@export var impostor_fade_in_end := 10.0
+@export var grass_fade_out_start := 10.0
+@export var grass_fade_out_end := 20.0
+
+
+func _process(delta: float) -> void:
+		var camera_pos
+
+		if Engine.is_editor_hint():
+				camera_pos = EditorInterface.get_editor_viewport_3d().get_camera_3d().global_position
+		else:
+				camera_pos = get_viewport().get_camera_3d().global_position
+
+		var camera_distance = global_position.distance_to(camera_pos)
+
+		if camera_distance < lod_switch:
+			$Grass.multimesh = preload("res://grass_multimesh_detailed.tres")
+		else:
+			$Grass.multimesh = preload("res://grass_multimesh_simple.tres")
+
+		var start_to_mid = smoothstep(impostor_fade_in_start, impostor_fade_in_end, camera_distance)
+		var mid_to_end = smoothstep(grass_fade_out_start, grass_fade_out_end, camera_distance)
+		
+		$Grass.visible = mid_to_end < 1.0
+		$Impostor.visible = start_to_mid >= 0.0
+
+		# Interpolate
+		$Impostor.set_instance_shader_parameter("alpha", start_to_mid)
+		$Grass.set_instance_shader_parameter("alpha", 1.0 - mid_to_end)

grass_chunk.gd.uid

@@ -0,0 +1 @@
+uid://bbnhmrtk1fxnl

grass_chunk.tscn

@@ -0,0 +1,106 @@
+[gd_scene load_steps=20 format=3 uid="uid://cnhjdcsr1e0ov"]
+
+[ext_resource type="Script" path="res://grass_chunk.gd" id="1_ofmm3"]
+[ext_resource type="Shader" uid="uid://db6rwrkgyosy0" path="res://grass.gdshader" id="2_0pvim"]
+[ext_resource type="MultiMesh" uid="uid://3l6gx28y48io" path="res://grass_multimesh_detailed.tres" id="3_ofmm3"]
+[ext_resource type="Script" uid="uid://bmx385ngdvuwt" path="res://grass.gd" id="4_sx5rw"]
+[ext_resource type="Shader" path="res://impostor_grass.gdshader" id="5_ry5bi"]
+[ext_resource type="Texture2D" uid="uid://bkm3w1ujws8d7" path="res://grass_normals.png" id="6_pxbre"]
+
+[sub_resource type="Gradient" id="Gradient_odt3n"]
+offsets = PackedFloat32Array(0)
+colors = PackedColorArray(0, 0, 0, 1)
+
+[sub_resource type="GradientTexture1D" id="GradientTexture1D_jugg6"]
+gradient = SubResource("Gradient_odt3n")
+
+[sub_resource type="StandardMaterial3D" id="StandardMaterial3D_301yx"]
+albedo_color = Color(0, 0, 0, 1)
+ao_enabled = true
+ao_light_affect = 1.0
+ao_texture = SubResource("GradientTexture1D_jugg6")
+
+[sub_resource type="PlaneMesh" id="PlaneMesh_n0l7m"]
+size = Vector2(5, 5)
+
+[sub_resource type="FastNoiseLite" id="FastNoiseLite_tid6t"]
+
+[sub_resource type="NoiseTexture2D" id="NoiseTexture2D_h2qfw"]
+seamless = true
+noise = SubResource("FastNoiseLite_tid6t")
+
+[sub_resource type="FastNoiseLite" id="FastNoiseLite_tlwt5"]
+frequency = 0.0043
+fractal_type = 2
+fractal_gain = 0.45
+
+[sub_resource type="NoiseTexture2D" id="NoiseTexture2D_aqk2v"]
+seamless = true
+noise = SubResource("FastNoiseLite_tlwt5")
+
+[sub_resource type="ShaderMaterial" id="ShaderMaterial_fj7yv"]
+render_priority = 0
+shader = ExtResource("2_0pvim")
+shader_parameter/size_small = 0.2
+shader_parameter/size_large = 0.6
+shader_parameter/blade_bend = 0.5
+shader_parameter/color_small = Color(0.3, 0.6, 0.1, 1)
+shader_parameter/color_large = Color(0.9, 0.9, 0.2, 1)
+shader_parameter/patch_noise = SubResource("NoiseTexture2D_h2qfw")
+shader_parameter/patch_scale = 5.0
+shader_parameter/wind_noise = SubResource("NoiseTexture2D_aqk2v")
+shader_parameter/wind_strength = 0.15
+shader_parameter/wind_direction = Vector2(1, 0)
+shader_parameter/wind_bend_strength = 2.0
+shader_parameter/wind_ao_affect = 1.0
+shader_parameter/object_radius = 1.0
+shader_parameter/object_position = Vector3(0, 0.3, 0)
+
+[sub_resource type="FastNoiseLite" id="FastNoiseLite_aqk2v"]
+frequency = 0.1
+
+[sub_resource type="NoiseTexture2D" id="NoiseTexture2D_036b0"]
+seamless_blend_skirt = 0.0
+noise = SubResource("FastNoiseLite_aqk2v")
+
+[sub_resource type="ShaderMaterial" id="ShaderMaterial_036b0"]
+render_priority = 0
+shader = ExtResource("5_ry5bi")
+shader_parameter/color_small = Color(0.3, 0.6, 0.1, 1)
+shader_parameter/color_large = Color(0.9, 0.9, 0.2, 1)
+shader_parameter/ground_color = Color(0, 0, 0, 1)
+shader_parameter/patch_noise = SubResource("NoiseTexture2D_h2qfw")
+shader_parameter/patch_scale = 5.0
+shader_parameter/high_frequency_noise = SubResource("NoiseTexture2D_036b0")
+shader_parameter/baked_normals = ExtResource("6_pxbre")
+shader_parameter/wind_noise = SubResource("NoiseTexture2D_aqk2v")
+shader_parameter/wind_strength = 0.1
+shader_parameter/wind_direction = Vector2(1, 0)
+shader_parameter/wind_bend_strength = 2.0
+shader_parameter/wind_ao_affect = 1.5
+
+[sub_resource type="PlaneMesh" id="PlaneMesh_dwbse"]
+size = Vector2(5, 5)
+
+[node name="GrassChunk" type="Node3D"]
+script = ExtResource("1_ofmm3")
+lod_switch = 7.0
+
+[node name="Ground" type="MeshInstance3D" parent="."]
+material_override = SubResource("StandardMaterial3D_301yx")
+mesh = SubResource("PlaneMesh_n0l7m")
+skeleton = NodePath("../..")
+
+[node name="Grass" type="MultiMeshInstance3D" parent="."]
+material_override = SubResource("ShaderMaterial_fj7yv")
+cast_shadow = 0
+instance_shader_parameters/alpha = 1.0
+multimesh = ExtResource("3_ofmm3")
+script = ExtResource("4_sx5rw")
+
+[node name="Impostor" type="MeshInstance3D" parent="."]
+transform = Transform3D(1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0.01, 0)
+material_override = SubResource("ShaderMaterial_036b0")
+instance_shader_parameters/alpha = 0.471145
+mesh = SubResource("PlaneMesh_dwbse")
+skeleton = NodePath("../..")

grass_grid.gd

@@ -0,0 +1,30 @@
+@tool
+extends Node3D
+
+
+@export var extent := 10:
+	set(new_extent):
+		extent = new_extent
+		reload()
+@export var chunk_size := 5.0
+
+
+func _ready():
+	reload()
+
+
+func reload():
+	for child in get_children():
+		child.queue_free()
+	
+	for x in range(-extent / 2, extent):
+		for y in range(-extent / 2, extent):
+			var chunk = preload("res://grass_chunk.tscn").instantiate()
+			
+			chunk.position = Vector3(
+				chunk_size * x,
+				0.0,
+				chunk_size * y
+			)
+			
+			add_child(chunk)

grass_grid.gd.uid

@@ -0,0 +1 @@
+uid://bi74il47aar6l

grass_normals.png.import

@@ -0,0 +1,35 @@
+[remap]
+
+importer="texture"
+type="CompressedTexture2D"
+uid="uid://bkm3w1ujws8d7"
+path.s3tc="res://.godot/imported/grass_normals.png-9b451e629acb5e2749c3e593a0ea92f5.s3tc.ctex"
+metadata={
+"imported_formats": ["s3tc_bptc"],
+"vram_texture": true
+}
+
+[deps]
+
+source_file="res://grass_normals.png"
+dest_files=["res://.godot/imported/grass_normals.png-9b451e629acb5e2749c3e593a0ea92f5.s3tc.ctex"]
+
+[params]
+
+compress/mode=2
+compress/high_quality=false
+compress/lossy_quality=0.7
+compress/hdr_compression=1
+compress/normal_map=1
+compress/channel_pack=0
+mipmaps/generate=true
+mipmaps/limit=-1
+roughness/mode=0
+roughness/src_normal=""
+process/fix_alpha_border=true
+process/premult_alpha=false
+process/normal_map_invert_y=false
+process/hdr_as_srgb=false
+process/hdr_clamp_exposure=false
+process/size_limit=0
+detect_3d/compress_to=0

impostor_grass.gdshader

@@ -0,0 +1,61 @@
+shader_type spatial;
+
+uniform vec3 color_small: source_color = vec3(0.3, 0.6, 0.1);
+uniform vec3 color_large: source_color = vec3(0.9, 0.9, 0.2);
+
+uniform vec3 ground_color: source_color = vec3(0.0, 0.0, 0.0);
+
+uniform sampler2D patch_noise;
+uniform float patch_scale = 5.0;
+
+uniform sampler2D high_frequency_noise: filter_linear_mipmap_anisotropic;
+uniform sampler2D baked_normals: hint_normal, filter_linear_mipmap_anisotropic;
+
+uniform sampler2D wind_noise;
+uniform float wind_strength = 0.1;
+uniform vec2 wind_direction = vec2(1.0, 0.0);
+uniform float wind_bend_strength = 2.0;
+uniform float wind_ao_affect = 1.5;
+
+instance uniform float alpha = 1.0;
+
+varying vec3 world_vertex;
+
+void vertex() {
+	world_vertex = (MODEL_MATRIX * vec4(VERTEX, 1.0)).xyz;
+}
+
+void fragment() {
+	float normal_to_view = 1.0 - dot(VIEW, NORMAL);
+
+	float patch_factor = texture(patch_noise, world_vertex.xz / patch_scale).r;
+	patch_factor = mix(patch_factor, 1.0, normal_to_view * 0.4);
+
+	ALBEDO = mix(color_small, color_large, patch_factor);
+
+	float high_frequency_sample = texture(high_frequency_noise, world_vertex.xz / patch_scale, -1.0).r;
+
+	float spottiness = (1.0 - normal_to_view) * 0.5 - patch_factor * 0.2;
+	float ground_factor = smoothstep(spottiness + 0.1, spottiness - 0.1, high_frequency_sample);
+
+	ALBEDO = mix(ALBEDO, ground_color, clamp(ground_factor + 1.0 - alpha, 0.0, 1.0));
+
+	// Wind
+	vec2 wind_position = world_vertex.xz / 10.0;
+	wind_position -= (TIME + 8.0) * wind_direction * wind_strength;
+
+	float current_wind_bend = texture(wind_noise, wind_position).x;
+	current_wind_bend *= wind_strength * 2.0;
+
+	float bottom_to_top_simulation = high_frequency_sample + smoothstep(0.6, 1.0, normal_to_view) * 0.4;
+	AO = mix(0.5, 1.0, bottom_to_top_simulation) - current_wind_bend * wind_ao_affect;
+	AO_LIGHT_AFFECT = 1.0;
+
+	// Normal Map
+	NORMAL_MAP = texture(baked_normals, world_vertex.xz / 5.0, -1.0).xyz;
+
+	// Lighting
+	BACKLIGHT = vec3(0.2);
+	ROUGHNESS = 0.4;
+	SPECULAR = 0.12;
+}

impostor_grass.gdshader.uid

@@ -0,0 +1 @@
+uid://dtufyv24svwrw