Add va_shader_example.txt

godot/effects/npc/wall_struggler/va_shader_example.txt

@@ -0,0 +1,42 @@
+
+uniform sampler2D offset_map;
+uniform sampler2D normal_map;
+
+uniform float start_frame = 0;
+uniform float end_frame = 70.0;
+uniform float time_scale = 0.5;
+
+void vertex(){
+	
+	float time_int = 1.0;
+	float time = modf(TIME * time_scale, time_int);
+	float num_frames = end_frame - start_frame;
+	float frame_offset = num_frames * INSTANCE_CUSTOM.a;
+	float current_frame = start_frame + mod((time * num_frames) + frame_offset, num_frames);
+	
+	ivec2 tex_size = textureSize(offset_map, 0);
+	float pixel_size = 1.0 / float(tex_size.y);
+	float frame_floor = clamp(floor(current_frame), start_frame, end_frame);
+	float frame_ceil = clamp(ceil(current_frame), start_frame, end_frame);
+	
+	vec2 frame_floor_uv_offset = vec2(0.0, -((frame_floor + 0.5) * pixel_size));
+	vec2 frame_ceil_uv_offset = vec2(0.0, -((frame_ceil + 0.5) * pixel_size));
+	
+	float lerp_factor = current_frame - frame_floor;
+	
+	vec3 offset_floor = texture(offset_map, UV2 + frame_floor_uv_offset).xyz;
+	vec3 offset_ceil = texture(offset_map, UV2 + frame_ceil_uv_offset).xyz;
+	vec3 offset_lerp = mix(offset_floor, offset_ceil, lerp_factor);
+	vec3 new_offset = vec3(offset_lerp.x, offset_lerp.z, offset_lerp.y);
+	
+	VERTEX += new_offset;
+	
+	vec3 normal_floor = texture(normal_map, UV2 + frame_floor_uv_offset).xyz;
+	vec3 normal_ceil = texture(normal_map, UV2 + frame_ceil_uv_offset).xyz;
+	vec3 normal_lerp = mix(normal_floor, normal_ceil, lerp_factor);
+	vec3 new_normal = vec3((normal_lerp.x * 2.0) - 1.0, (normal_lerp.z * 2.0) - 1.0, (normal_lerp.y * 2.0) - 1.0);
+	
+	NORMAL = new_normal;
+	
+	
+}