[Unity3D]Shader编程之贴图切换

本shader实现基于世界坐标的贴图置换效果。

效果如下：

设置面板如下：

可在面板上设置切换方向，与切换对象，及其切换速度。

shader实现如下：

Shader "XM/Effect/SwapTexture" {    Properties {        _Color ("Color", Color) = (1,1,1,1)        _MainTex ("Albedo (RGB)", 2D) = "white" {}        _TargetTex ("Target Tex", 2D) = "white" {}//目标贴图        [KeywordEnum(Up, Down, Left, Right, Forward, Back)] _mode ("Mode", Int) = 0//切换方向        _SwapBlend ("Blend", Range(0,1)) = 0//0-1混合值        _SwapMin("Min Value", Float) = 0//最小世界坐标        _SwapMax("Max Value", Float) = 0//最大世界坐标        _Glossiness ("Smoothness", Range(0,1)) = 0.5        _Metallic ("Metallic", Range(0,1)) = 0.0    }    SubShader {        Tags { "RenderType"="Opaque" }        LOD 200        CGPROGRAM        // Physically based Standard lighting model, and enable shadows on all light types        #pragma surface surf Standard fullforwardshadows vertex:vert        // Use shader model 3.0 target, to get nicer looking lighting        #pragma target 3.0        sampler2D _MainTex;        sampler2D _TargetTex;        struct Input {            float2 uv_MainTex;            float3 worldPos;        };        half _mode;        half _SwapBlend;        float _SwapMin;        float _SwapMax;        half _Glossiness;        half _Metallic;        fixed4 _Color;        void vert (inout appdata_full v, out Input o) {          UNITY_INITIALIZE_OUTPUT(Input,o);        }        void surf (Input IN, inout SurfaceOutputStandard o) {            half useTarget = 0;            float targetValue = 0;            switch(_mode)//模式选择            {                case 0://up                    targetValue = (_SwapMax - _SwapMin) * _SwapBlend + _SwapMin;                    useTarget = IN.worldPos.y > targetValue?0:1;                    break;                case 1://down                    targetValue = (_SwapMax - _SwapMin) * (1 - _SwapBlend) + _SwapMin;                    useTarget = IN.worldPos.y < targetValue?0:1;                    break;                case 2://left                    targetValue = (_SwapMax - _SwapMin) * (1 - _SwapBlend) + _SwapMin;                    useTarget = IN.worldPos.x < targetValue?0:1;                    break;                case 3://right                    targetValue = (_SwapMax - _SwapMin) * _SwapBlend + _SwapMin;                    useTarget = IN.worldPos.x > targetValue?0:1;                    break;                case 4://forward                    targetValue = (_SwapMax - _SwapMin) * _SwapBlend + _SwapMin;                    useTarget = IN.worldPos.z > targetValue?0:1;                    break;                case 5://back                    targetValue = (_SwapMax - _SwapMin) * (1 - _SwapBlend) + _SwapMin;                    useTarget = IN.worldPos.z < targetValue?0:1;                    break;            }            // Albedo comes from a texture tinted by color            fixed4 c;            if(useTarget == 1)            {                c = tex2D (_TargetTex, IN.uv_MainTex);            }            else            {                c = tex2D (_MainTex, IN.uv_MainTex);            }            c *= _Color;            o.Albedo = c.rgb;            // Metallic and smoothness come from slider variables            o.Metallic = _Metallic;            o.Smoothness = _Glossiness;            o.Alpha = c.a;        }        ENDCG    }    FallBack "Diffuse"}

配合使用的脚本如下：

using System;using System.Collections;using UnityEngine;namespace XM.Effect{    public class SwapTexture : MonoBehaviour    {        public enum SwapDirection        {            Up,            Down,            Left,            Right,            Forward,            Back        }        public Shader _shader;//"XM/Effect/SwapTexture” shader        public SwapDirection _swapDir;//切换方向        public Renderer _target;//目标对象        [Range(0, 1)]        public float _speed;//速度        private Material _matOld;        private Material _matNew;        public void Swap(Texture tex, Action<bool> onComplete)        {            if (_matOld != null)            {                StopAllCoroutines();                if (null != onComplete)                {                    onComplete(false);                }                _target.material = _matOld;            }            _matOld = _target.material;            _matNew = new Material(_shader);            _matNew.SetTexture("_MainTex", _target.material.GetTexture("_MainTex"));            _matNew.SetTexture("_TargetTex", tex);            _matNew.SetInt("_mode", (int)_swapDir);            _matNew.SetFloat("_SwapBlend", 0);            StartCoroutine("_StartChange", onComplete);        }        private IEnumerator _StartChange(Action<bool> onComplete)        {            float deltaVal = 0;            _target.material = _matNew;            Vector3 vtMin;            Vector3 vtMax;            float minVal = 0;            float maxVal = 0;            while (deltaVal != 1)            {                vtMin = _target.bounds.min;                vtMax = _target.bounds.max;                switch (_swapDir)                {                    case SwapDirection.Up:                    case SwapDirection.Down:                        minVal = vtMin.y;                        maxVal = vtMax.y;                        break;                    case SwapDirection.Left:                    case SwapDirection.Right:                        minVal = vtMin.x;                        maxVal = vtMax.x;                        break;                    case SwapDirection.Forward:                    case SwapDirection.Back:                        minVal = vtMin.z;                        maxVal = vtMax.z;                        break;                }                minVal -= 0.01f;                maxVal += 0.01f;                _matNew.SetFloat("_SwapMin", minVal);                _matNew.SetFloat("_SwapMax", maxVal);                deltaVal = Mathf.Clamp01(deltaVal + _speed * Time.deltaTime);                _matNew.SetFloat("_SwapBlend", deltaVal);                yield return null;            }            _matOld.SetTexture("_MainTex", _matNew.GetTexture("_TargetTex"));            _target.material = _matOld;            _matNew = null;            _matOld = null;            if (null != onComplete)            {                onComplete(true);            }        }        public void OnDrawGizmos()        {            if (_target != null)            {                Gizmos.DrawWireCube(_target.bounds.center, _target.bounds.size);                Gizmos.DrawWireSphere(_target.bounds.min, 0.1f);                Gizmos.DrawWireSphere(_target.bounds.max, 0.1f);            }        }        //test        public Texture testTex;        private void OnGUI()        {            if (GUILayout.Button("SwapTexture"))            {                Swap(testTex, (t) =>                {                    Debug.Log("Swap>" + t);                });            }        }        //    }}