Question

首先，请允许我解释一下我所拥有的，然后再讨论下一个要解决的问题。

我所拥有的

我有一个带纹理的自定义网格物体，它的某些边缘与Unity中的整数世界坐标完全对齐。在网格中，我添加了自己的粗略有效的自定义表面着色器，如下所示：

    Shader "Custom/GridHighlightShader"
{
    Properties
    {
        [HideInInspector]_SelectionColor("SelectionColor", Color) = (0.1,0.1,0.1,1)
        [HideInInspector]_MovementColor("MovementColor", Color) = (0,0.205,1,1)
        [HideInInspector]_AttackColor("AttackColor", Color) = (1,0,0,1)
        [HideInInspector]_GlowInterval("_GlowInterval", float) = 1
        _MainTex("Albedo (RGB)", 2D) = "white" {}
        _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

            // Use shader model 3.0 target, to get nicer looking lighting
            #pragma target 3.0

            struct Input
            {
                float2 uv_MainTex;
                float3 worldNormal;
                float3 worldPos;
            };

            sampler2D _MainTex;
            half _Glossiness;
            half _Metallic;
            fixed4 _SelectionColor;
            fixed4 _MovementColor;
            fixed4 _AttackColor;
            half _GlowInterval;
            half _ColorizationArrayLength = 0;
            float4 _ColorizationArray[600];
            half _isPixelInColorizationArray = 0;

            // Add instancing support for this shader. You need to check 'Enable Instancing' on materials that use the shader.
            // See https://docs.unity3d.com/Manual/GPUInstancing.html for more information about instancing.
            // #pragma instancing_options assumeuniformscaling
            UNITY_INSTANCING_BUFFER_START(Props)
                // put more per-instance properties here
            UNITY_INSTANCING_BUFFER_END(Props)

                void surf(Input IN, inout SurfaceOutputStandard o)
                {
                fixed4 c = tex2D(_MainTex, IN.uv_MainTex);

                // Update only the normals facing up and down
                if (abs(IN.worldNormal.x) <= 0.5 && (abs(IN.worldNormal.z) <= 0.5))
                {
                    // If no colors were passed in, reset all of the colors
                    if (_ColorizationArray[0].w == 0)
                    {
                        _isPixelInColorizationArray = 0;
                    }
                    else
                    {
                        for (int i = 0; i < _ColorizationArrayLength; i++)
                        {
                            if (abs(IN.worldPos.x) >= _ColorizationArray[i].x && abs(IN.worldPos.x) < _ColorizationArray[i].x + 1
                                && abs(IN.worldPos.z) >= _ColorizationArray[i].z && abs(IN.worldPos.z) < _ColorizationArray[i].z + 1
                                )
                            {
                                _isPixelInColorizationArray = _ColorizationArray[i].w;
                            }
                        }
                    }

                    if (_isPixelInColorizationArray > 0)
                    {
                        if (_isPixelInColorizationArray == 1)
                        {
                            c = tex2D(_MainTex, IN.uv_MainTex) + (_SelectionColor * _GlowInterval) - 1;
                        }
                        else if (_isPixelInColorizationArray == 2)
                        {
                            c = tex2D(_MainTex, IN.uv_MainTex) + (_MovementColor * _GlowInterval);
                        }
                        else if (_isPixelInColorizationArray == 3)
                        {
                            c = tex2D(_MainTex, IN.uv_MainTex) + (_AttackColor * _GlowInterval);
                        }
                    }
                }
                o.Albedo = c.rgb;
                o.Metallic = _Metallic;
                o.Smoothness = _Glossiness;
                o.Alpha = c.a;

            }
            ENDCG
        }
            FallBack "Diffuse"
}

使用一些数学函数，将浮点数随时间推移在2和3之间波动，这是通过Unity中的一个简单更新函数完成的：

private void Update() 
{
    var t = (2 + ((Mathf.Sin(Time.time))));
    meshRenderer.material.SetFloat("_GlowInterval", t);
}

我还向着色器提供了一个名为_ColorizationArray的Vector4数组，该数组存储0到600个坐标，每个坐标表示在运行时要着色的图块。这些切片可能会或可能不会突出显示，具体取决于它们在运行时的selectionMode值。这是我用来执行此操作的方法：

    public void SetColorizationCollectionForShader()
    {
        var coloredTilesArray = Battlemap.Instance.tiles.Where(x => x.selectionMode != TileSelectionMode.None).ToArray();

        // https://docs.unity3d.com/ScriptReference/Material.SetVectorArray.html                
        // Set the tile count in the shader's own integer variable
        meshRenderer.material.SetInt("_ColorizationArrayLength", coloredTilesArray.Length);

        // Loop through the tiles to be colored only and grab their world coordinates
        for(int i = 0; i < coloredTilesArray.Length; i++)
        {
            // Also grab the selection mode as the w value of a float4
            colorizationArray[i] = new Vector4(coloredTilesArray[i].x - Battlemap.HALF_TILE_SIZE, coloredTilesArray[i].y, coloredTilesArray[i].z - Battlemap.HALF_TILE_SIZE, (float)coloredTilesArray[i].selectionMode);            
        }

        // Feed the overwritten array into the shader
        meshRenderer.material.SetVectorArray("_ColorizationArray", colorizationArray);
    }

结果是在运行时动态设置和更改的一组蓝色发光瓷砖：

我所有的目标是在网格上的战术游戏中突出显示网格上的正方形（或瓷砖，如果可以的话），其中单位可以移动到突出显示区域内的任何瓷砖。每个单位移动后，它可能会遭受攻击，其中瓷砖会突出显示为红色，然后下一个单位将其转身，依此类推。由于我希望AI，运动计算和粒子效果会占用大部分处理时间，因此我需要在运行时动态且非常高效地突出显示图块。

下一步我想做什么

哦，好的。现在，如果您对着色器一无所知（我当然不知道，我昨天才开始看cg代码），您可能会想：“哦，亲爱的上帝，这是一个低效的烂摊子。您在做什么？！如果声明？！在着色器？”而且我不会怪你。

我真正想做的几乎是同一件事，只是效率更高。使用特定的图块索引，我想告诉着色器“将这些图块内部的表面着色为蓝色，并且仅对这些图块进行着色”，并以对GPU和CPU都有效的方式进行着色。

我该如何实现？我已经在用C＃代码计算平铺世界的坐标并将坐标提供给着色器，但是除此之外，我很茫然。我意识到我可能应该切换到顶点/片段着色器，但我还要尽可能避免丢失网格上的任何默认动态光照。

还有，是否存在一种变量类型，该变量将允许着色器使用局部网格坐标而不是世界坐标将网格着色为蓝色？能够移动网格而不必担心着色器代码会很好。

编辑：自发布此问题以来的2周中，我通过传入一个Vector4s数组（其中一半代表实际要处理的数组_ColorizationArrayLength）来对着色器进行了编辑，效果很好，但效率几乎没有提高-这会产生GPU尖峰，在相当现代的图形卡上处理大约需要17ms。我已经更新了上面的着色器代码以及原始问题的一部分。

Answer 1

由于您的着色只关心在均等大小且均对准同一网格的正方形网格中的2d位置，因此我们可以传递2d纹理，其颜色表示地面应着色的方式。

在着色器中，添加一个2D _ColorizeMap和一个Vector _WorldSpaceRange。该地图将用于传递应该对世界的各个部分进行着色的范围，并且范围将告诉着色器如何在世界空间和UV（纹理）空间之间进行转换。由于游戏网格与世界x / y轴对齐，因此我们可以线性缩放从世界空间到UV空间的坐标。

然后，当法线朝上时（您可以检查法线的y是否足够高），获得世界位置的倒数，并从_ColorizeMap进行采样以获取应否彩色的。

Shader "Custom/GridHighlightShader"
{
    Properties
    {
        [HideInInspector]_GlowInterval("_GlowInterval", float) = 1
        _MainTex("Albedo (RGB)", 2D) = "white" {}
        _Glossiness("Smoothness", Range(0,1)) = 0.5
        _Metallic("Metallic", Range(0,1)) = 0.0
        [HideInInspector]_ColorizeMap("Colorize Map", 2D) = "black" {} 
        _WorldSpaceRange("World Space Range", Vector) = (0,0,100,100)
    }
        SubShader
        {
            Tags { "RenderType" = "Opaque" }
            LOD 200

            CGPROGRAM
            // Physically based Standard lighting model, 
            // and enable shadows on all light types
            #pragma surface surf Standard fullforwardshadows

            // Use shader model 3.0 target, to get nicer looking lighting
            #pragma target 3.0

            struct Input
            {
                float2 uv_MainTex;
                float3 worldNormal;
                float3 worldPos;
            };

            sampler2D _MainTex;
            half _Glossiness;
            half _Metallic;
            half _GlowInterval;

            sampler2D _ColorizeMap;
            fixed4 _WorldSpaceRange;


            // Add instancing support for this shader. 
            // You need to check 'Enable Instancing' on materials that use the shader.
            // See https://docs.unity3d.com/Manual/GPUInstancing.html 
            // for more information about instancing.
            // #pragma instancing_options assumeuniformscaling
            UNITY_INSTANCING_BUFFER_START(Props)
                // put more per-instance properties here
            UNITY_INSTANCING_BUFFER_END(Props)

            void surf(Input IN, inout SurfaceOutputStandard o)
            {
                fixed4 c = tex2D(_MainTex, IN.uv_MainTex);

                // Update only the normals facing up and down
                if (abs(IN.worldNormal.y) >= 0.866)) // abs(y) >= sin(60 degrees)
                {
                    fixed4 colorizedMapUV = (IN.worldPos.xz-_WorldSpaceRange.xy) 
                            / (_WorldSpaceRange.zw-_WorldSpaceRange.xy);

                    half4 colorType = tex2D(_ColorizeMap, colorizedMapUV);

                    c = c + (colorType * _GlowInterval); 
                }
                o.Albedo = c.rgb;
                o.Metallic = _Metallic;
                o.Smoothness = _Glossiness;
                o.Alpha = c.a;

            }
            ENDCG
        }
    FallBack "Diffuse"
}

并删除分支：

Shader "Custom/GridHighlightShader"
{
    Properties
    {
        [HideInInspector]_GlowInterval("_GlowInterval", float) = 1
        _MainTex("Albedo (RGB)", 2D) = "white" {}
        _Glossiness("Smoothness", Range(0,1)) = 0.5
        _Metallic("Metallic", Range(0,1)) = 0.0
        [HideInInspector]_ColorizeMap("Colorize Map", 2D) = "black" {}
        _WorldSpaceRange("World Space Range", Vector) = (0,0,100,100)
    }
        SubShader
        {
            Tags { "RenderType" = "Opaque" }
            LOD 200
            CGPROGRAM
            // Physically based Standard lighting model, 
            // and enable shadows on all light types
            #pragma surface surf Standard fullforwardshadows

            // Use shader model 3.0 target, to get nicer looking lighting
            #pragma target 3.0

            struct Input
            {
                float2 uv_MainTex;
                float3 worldNormal;
                float3 worldPos;
            };

            sampler2D _MainTex;
            half _Glossiness;
            half _Metallic;
            half _GlowInterval;

            sampler2D _ColorizeMap;
            fixed4 _WorldSpaceRange;

            // Add instancing support for this shader.
            // You need to check 'Enable Instancing' on materials that use the shader.
            // See https://docs.unity3d.com/Manual/GPUInstancing.html 
            // for more information about instancing.
            // #pragma instancing_options assumeuniformscaling
            UNITY_INSTANCING_BUFFER_START(Props)
                // put more per-instance properties here
            UNITY_INSTANCING_BUFFER_END(Props)

            void surf(Input IN, inout SurfaceOutputStandard o)
            {

                half4 c = tex2D(_MainTex, IN.uv_MainTex);
                float2 colorizedMapUV = (IN.worldPos.xz - _WorldSpaceRange.xy)
                        / (_WorldSpaceRange.zw - _WorldSpaceRange.xy);
                half4 colorType = tex2D(_ColorizeMap, colorizedMapUV);

                // abs(y) >= sin(60 degrees) = 0.866
                c = c + step(0.866, abs(IN.worldNormal.y)) * colorType * _GlowInterval;

                o.Albedo = c.rgb;
                o.Metallic = _Metallic;
                o.Smoothness = _Glossiness;
                o.Alpha = c.a;

            }
            ENDCG
        }
            FallBack "Diffuse"
}

然后在您的C＃代码中创建一个无需过滤的纹理。以全黑开始纹理，然后根据突出显示方式向纹理添加颜色。另外，告诉着色器颜色图所表示的世界空间中的范围（minX，minZ，maxX，maxZ）：

    public void SetColorizationCollectionForShader()
{   
    Color[] selectionColors = new Color[4] { Color.clear, new Color(0.5f, 0.5f, 0.5f, 0.5f), Color.blue, Color.red };
    float leftMostTileX = 0f + Battlemap.HALF_TILE_SIZE;
    float backMostTileZ = 0f + Battlemap.HALF_TILE_SIZE;

    float rightMostTileX = leftMostTileX + (Battlemap.Instance.GridMaxX - 1)
            * Battlemap.TILE_SIZE;
    float forwardMostTileZ = backMostTileZ + (Battlemap.Instance.GridMaxZ - 1)
            * Battlemap.TILE_SIZE;

    Texture2D colorTex = new Texture2D(Battlemap.Instance.GridMaxX, Battlemap.Instance.GridMaxZ);
    colorTex.filterMode = FilterMode.Point;

    Vector4 worldRange = new Vector4(
            leftMostTileX - Battlemap.HALF_TILE_SIZE,
            backMostTileZ - Battlemap.HALF_TILE_SIZE,
            rightMostTileX + Battlemap.HALF_TILE_SIZE,
            forwardMostTileZ + Battlemap.HALF_TILE_SIZE);

    meshRenderer.material.SetVector("_WorldSpaceRange", worldRange);        

    // Loop through the tiles to be colored only and grab their world coordinates
    for (int i = 0; i < Battlemap.Instance.tiles.Length; i++)
    {
        // determine pixel index from position
        float xT = Mathf.InverseLerp(leftMostTileX, rightMostTileX,
                Battlemap.Instance.tiles[i].x);
        int texXPos = Mathf.RoundToInt(Mathf.Lerp(0f, Battlemap.Instance.GridMaxX - 1.0f, xT));

        float yT = Mathf.InverseLerp(backMostTileZ, forwardMostTileZ,
                Battlemap.Instance.tiles[i].z);
        int texYPos = Mathf.RoundToInt(Mathf.Lerp(0f, Battlemap.Instance.GridMaxZ - 1.0f, yT));

        colorTex.SetPixel(texXPos, texYPos, selectionColors[(int)Battlemap.Instance.tiles[i].selectionMode]);
    }
    colorTex.Apply();

    // Feed the color map into the shader
    meshRenderer.material.SetTexture("_ColorizeMap", colorTex);
}

在图块的边界处可能有些晃动，并且纹理空间/世界空间之间可能存在对齐问题，但这应该可以帮助您入门。

Unity Shader-如何有效地重新着色特定坐标？

1 个答案: