ScriptableRenderPipeline/ScriptableRenderPipeline/HDRenderPipeline/HDRP/Wind/ShaderWindSettings.cs

using UnityEngine;

namespace UnityEngine.Experimental.Rendering.HDPipeline
{
    [ExecuteInEditMode]
    public class ShaderWindSettings : MonoBehaviour
    {

        [Header("General Parameters")]
        [Tooltip("Wind Speed in Kilometers per hour")]
        public float WindSpeed = 30;
        [Range(0.0f, 2.0f)]
        [Tooltip("Wind Turbulence in percentage of wind Speed")]
        public float Turbulence  = 0.25f;


        [Header("Noise Parameters")]
        [Tooltip("Texture used for wind turbulence")]
        public Texture2D NoiseTexture;
        [Tooltip("Size of one world tiling patch of the Noise Texture, for bending trees")]
        public float FlexNoiseWorldSize = 175.0f;
        [Tooltip("Size of one world tiling patch of the Noise Texture, for leaf shivering")]
        public float ShiverNoiseWorldSize = 10.0f;

        [Header("Gust Parameters")]
        [Tooltip("Texture used for wind gusts")]
        public Texture2D GustMaskTexture;
        [Tooltip("Size of one world tiling patch of the Gust Texture, for leaf shivering")]
        public float GustWorldSize = 600.0f;

        [Tooltip("Wind Gust Speed in Kilometers per hour")]
        public float GustSpeed = 50;
        [Tooltip("Wind Gust Influence on trees")]
        public float GustScale = 1.0f;


        // Use this for initialization
        void Start()
        {
            ApplySettings();
        }

        // Update is called once per frame
        void Update()
        {
            ApplySettings();
        }

        void OnValidate()
        {
            ApplySettings();
        }

        void ApplySettings()
        {
            Shader.SetGlobalTexture("_WIND_SETTINGS_TexNoise", NoiseTexture);
            Shader.SetGlobalTexture("_WIND_SETTINGS_TexGust", GustMaskTexture);
            Shader.SetGlobalVector("WIND_SETTINGS_WorldDirectionAndSpeed", GetDirectionAndSpeed());
            Shader.SetGlobalFloat("WIND_SETTINGS_FlexNoiseScale", 1.0f / Mathf.Max(0.01f, FlexNoiseWorldSize));
            Shader.SetGlobalFloat("WIND_SETTINGS_ShiverNoiseScale", 1.0f / Mathf.Max(0.01f, ShiverNoiseWorldSize));
            Shader.SetGlobalFloat("WIND_SETTINGS_Turbulence", WindSpeed * Turbulence);
            Shader.SetGlobalFloat("WIND_SETTINGS_GustSpeed", GustSpeed);
            Shader.SetGlobalFloat("WIND_SETTINGS_GustScale", GustScale);
            Shader.SetGlobalFloat("WIND_SETTINGS_GustWorldScale", 1.0f / Mathf.Max(0.01f, GustWorldSize));
        }

        Vector4 GetDirectionAndSpeed()
        {
            Vector3 dir = transform.forward.normalized;
            return new Vector4(dir.x, dir.y, dir.z, WindSpeed * 0.2777f);
        }

        //void OnDrawGizmos()
        //{
        //    Vector3 dir = (transform.position + transform.forward).normalized;

        //    Gizmos.color = Color.green;
        //    Gizmos.DrawIcon(transform.position, "Wind.png", false);
        //    Vector3 up = transform.up;
        //    Vector3 side = transform.right;

        //    Vector3 end = transform.position + transform.forward * WindSpeed;
        //    Gizmos.DrawLine(transform.position, end);

        //    float s = WindSpeed * 0.05f;
        //    Vector3 front = transform.forward * WindSpeed * 0.1f;

        //    Gizmos.DrawLine(end, end - front + up * s);
        //    Gizmos.DrawLine(end, end - front - up * s);
        //    Gizmos.DrawLine(end, end - front + side * s);
        //    Gizmos.DrawLine(end, end - front - side * s);

        //    Gizmos.DrawLine(end - front - side * s, end - front + up * s);
        //    Gizmos.DrawLine(end - front + up * s, end - front + side * s);
        //    Gizmos.DrawLine(end - front + side * s, end - front - up * s);
        //    Gizmos.DrawLine(end - front - up * s, end - front - side * s);
        //}
    }
}