Text Mesh Pro, world space mask

Hi!
I’ve the need to implement a world space mask on TextMeshPro component.
I saw the shader “Distance Field - Masking”, but it does that in object space with a clip rect. Is it possible to get the same behaviour in world space?

Thank you in advance

Hi,
Better late than never… in case someone still need this.
I didn’t remember where I found this Shader but it’s very usefull and I think must be included in TextMeshPro package.

// Upgrade NOTE: replaced 'mul(UNITY_MATRIX_MVP,*)' with 'UnityObjectToClipPos(*)'

// Copyright (C) 2014 - 2016 Stephan Schaem - All Rights Reserved
// This code can only be used under the standard Unity Asset Store End User License Agreement
// A Copy of the EULA APPENDIX 1 is available at http://unity3d.com/company/legal/as_terms

// Simplified SDF shader:
// - No Shading Option (bevel / bump / env map)
// - No Glow Option
// - Softness is applied on both side of the outline

Shader "TextMeshPro/Mobile/Distance Field - Worldspace Masking" {

Properties {
    _FaceColor            ("Face Color", Color) = (1,1,1,1)
    _FaceDilate            ("Face Dilate", Range(-1,1)) = 0

    _OutlineColor        ("Outline Color", Color) = (0,0,0,1)
    _OutlineWidth        ("Outline Thickness", Range(0,1)) = 0
    _OutlineSoftness    ("Outline Softness", Range(0,1)) = 0

    _UnderlayColor        ("Border Color", Color) = (0,0,0,.5)
    _UnderlayOffsetX     ("Border OffsetX", Range(-1,1)) = 0
    _UnderlayOffsetY     ("Border OffsetY", Range(-1,1)) = 0
    _UnderlayDilate        ("Border Dilate", Range(-1,1)) = 0
    _UnderlaySoftness     ("Border Softness", Range(0,1)) = 0

    _WeightNormal        ("Weight Normal", float) = 0
    _WeightBold            ("Weight Bold", float) = .5

    _ShaderFlags        ("Flags", float) = 0
    _ScaleRatioA        ("Scale RatioA", float) = 1
    _ScaleRatioB        ("Scale RatioB", float) = 1
    _ScaleRatioC        ("Scale RatioC", float) = 1

    _MainTex            ("Font Atlas", 2D) = "white" {}
    _TextureWidth        ("Texture Width", float) = 512
    _TextureHeight        ("Texture Height", float) = 512
    _GradientScale        ("Gradient Scale", float) = 5
    _ScaleX                ("Scale X", float) = 1
    _ScaleY                ("Scale Y", float) = 1
    _PerspectiveFilter    ("Perspective Correction", Range(0, 1)) = 0.875

    _VertexOffsetX        ("Vertex OffsetX", float) = 0
    _VertexOffsetY        ("Vertex OffsetY", float) = 0

    _ClipRect            ("Clip Rect", vector) = (-32767, -32767, 32767, 32767)
    _MaskSoftnessX        ("Mask SoftnessX", float) = 0
    _MaskSoftnessY        ("Mask SoftnessY", float) = 0
  
    _StencilComp        ("Stencil Comparison", Float) = 8
    _Stencil            ("Stencil ID", Float) = 0
    _StencilOp            ("Stencil Operation", Float) = 0
    _StencilWriteMask    ("Stencil Write Mask", Float) = 255
    _StencilReadMask    ("Stencil Read Mask", Float) = 255
  
    _ColorMask            ("Color Mask", Float) = 15
}

SubShader {
    Tags
    {
        "Queue"="Transparent"
        "IgnoreProjector"="True"
        "RenderType"="Transparent"
    }


    Stencil
    {
        Ref [_Stencil]
        Comp [_StencilComp]
        Pass [_StencilOp]
        ReadMask [_StencilReadMask]
        WriteMask [_StencilWriteMask]
    }

    Cull [_CullMode]
    ZWrite Off
    Lighting Off
    Fog { Mode Off }
    ZTest [unity_GUIZTestMode]
    Blend One OneMinusSrcAlpha
    ColorMask [_ColorMask]

    Pass {
        CGPROGRAM
        #pragma vertex VertShader
        #pragma fragment PixShader
        #pragma shader_feature __ OUTLINE_ON
        #pragma shader_feature __ UNDERLAY_ON UNDERLAY_INNER

        #include "UnityCG.cginc"
        #include "UnityUI.cginc"
        #include "TMPro_Properties.cginc"

        struct vertex_t {
            float4    vertex            : POSITION;
            float3    normal            : NORMAL;
            fixed4    color            : COLOR;
            float2    texcoord0        : TEXCOORD0;
            float2    texcoord1        : TEXCOORD1;
        };

        struct pixel_t {
            float4    vertex            : SV_POSITION;
            fixed4    faceColor        : COLOR;
            fixed4    outlineColor    : COLOR1;
            float4    texcoord0        : TEXCOORD0;            // Texture UV, Mask UV
            half4    param            : TEXCOORD1;            // Scale(x), BiasIn(y), BiasOut(z), Bias(w)
            half4    mask            : TEXCOORD2;            // Position in clip space(xy), Softness(zw)
        #if (UNDERLAY_ON | UNDERLAY_INNER)
            float4    texcoord1        : TEXCOORD3;            // Texture UV, alpha, reserved
            half2    underlayParam    : TEXCOORD4;            // Scale(x), Bias(y)
        #endif
        };


        pixel_t VertShader(vertex_t input)
        {
            float bold = step(input.texcoord1.y, 0);

            float4 vert = input.vertex;
            vert.x += _VertexOffsetX;
            vert.y += _VertexOffsetY;
            float4 vPosition = UnityObjectToClipPos(vert);

            float2 pixelSize = vPosition.w;
            pixelSize /= float2(_ScaleX, _ScaleY) * abs(mul((float2x2)UNITY_MATRIX_P, _ScreenParams.xy));
          
            float scale = rsqrt(dot(pixelSize, pixelSize));
            scale *= abs(input.texcoord1.y) * _GradientScale * 1.5;
            if(UNITY_MATRIX_P[3][3] == 0) scale = lerp(abs(scale) * (1 - _PerspectiveFilter), scale, abs(dot(UnityObjectToWorldNormal(input.normal.xyz), normalize(WorldSpaceViewDir(vert)))));

            float weight = lerp(_WeightNormal, _WeightBold, bold) / 4.0;
            weight = (weight + _FaceDilate) * _ScaleRatioA * 0.5;

            float layerScale = scale;

            scale /= 1 + (_OutlineSoftness * _ScaleRatioA * scale);
            float bias = (0.5 - weight) * scale - 0.5;
            float outline = _OutlineWidth * _ScaleRatioA * 0.5 * scale;

            float opacity = input.color.a;
        #if (UNDERLAY_ON | UNDERLAY_INNER)
                opacity = 1.0;
        #endif

            fixed4 faceColor = fixed4(input.color.rgb, opacity) * _FaceColor;
            faceColor.rgb *= faceColor.a;

            fixed4 outlineColor = _OutlineColor;
            outlineColor.a *= opacity;
            outlineColor.rgb *= outlineColor.a;
            outlineColor = lerp(faceColor, outlineColor, sqrt(min(1.0, (outline * 2))));

        #if (UNDERLAY_ON | UNDERLAY_INNER)

            layerScale /= 1 + ((_UnderlaySoftness * _ScaleRatioC) * layerScale);
            float layerBias = (.5 - weight) * layerScale - .5 - ((_UnderlayDilate * _ScaleRatioC) * .5 * layerScale);

            float x = -(_UnderlayOffsetX * _ScaleRatioC) * _GradientScale / _TextureWidth;
            float y = -(_UnderlayOffsetY * _ScaleRatioC) * _GradientScale / _TextureHeight;
            float2 layerOffset = float2(x, y);
        #endif

            // Generate UV for the Masking Texture
            float4 clampedRect = clamp(_ClipRect, -2e10, 2e10);
            float2 maskUV = (vert.xy - clampedRect.xy) / (clampedRect.zw - clampedRect.xy);

            // Convert vertex position to world space position
            vert = mul(unity_ObjectToWorld, vert);

            // Structure for pixel shader
            pixel_t output = {
                vPosition,
                faceColor,
                outlineColor,
                float4(input.texcoord0.x, input.texcoord0.y, maskUV.x, maskUV.y),
                half4(scale, bias - outline, bias + outline, bias),
                half4(vert.xy * 2 - clampedRect.xy - clampedRect.zw, 0.25 / (0.25 * half2(_MaskSoftnessX, _MaskSoftnessY) + pixelSize.xy)),
            #if (UNDERLAY_ON | UNDERLAY_INNER)
                float4(input.texcoord0 + layerOffset, input.color.a, 0),
                half2(layerScale, layerBias),
            #endif
            };

            return output;
        }


        // PIXEL SHADER
        fixed4 PixShader(pixel_t input) : SV_Target
        {
            half d = tex2D(_MainTex, input.texcoord0.xy).a * input.param.x;
            half4 c = input.faceColor * saturate(d - input.param.w);

        #ifdef OUTLINE_ON
            c = lerp(input.outlineColor, input.faceColor, saturate(d - input.param.z));
            c *= saturate(d - input.param.y);
        #endif

        #if UNDERLAY_ON
            d = tex2D(_MainTex, input.texcoord1.xy).a * input.underlayParam.x;
            c += float4(_UnderlayColor.rgb * _UnderlayColor.a, _UnderlayColor.a) * saturate(d - input.underlayParam.y) * (1 - c.a);
        #endif

        #if UNDERLAY_INNER
            half sd = saturate(d - input.param.z);
            d = tex2D(_MainTex, input.texcoord1.xy).a * input.underlayParam.x;
            c += float4(_UnderlayColor.rgb * _UnderlayColor.a, _UnderlayColor.a) * (1 - saturate(d - input.underlayParam.y)) * sd * (1 - c.a);
        #endif

       
        /*#if UNITY_VERSION < 530
            // Unity 5.2 2D Rect Mask Support
            if (_UseClipRect)
            {
                half2 m = saturate((_ClipRect.zw - _ClipRect.xy - abs(input.mask.xy)) * input.mask.zw);
                c *= m.x * m.y;
            }
        #else*/
            // Alternative implementation to UnityGet2DClipping with support for softness.
            half2 m = saturate((_ClipRect.zw - _ClipRect.xy - abs(input.mask.xy)) * input.mask.zw);
            c *= m.x * m.y;
        //#endif

        #if (UNDERLAY_ON | UNDERLAY_INNER)
            c *= input.texcoord1.z;
        #endif

            clip(c.a - 0.001);

            return c;
        }
        ENDCG
    }
}

CustomEditor "TMPro.EditorUtilities.TMP_SDFShaderGUI"
}

Still working with Unity 2021.1 and URP.