Question

我在获取正确的屏幕坐标时遇到了麻烦，因此我做了一个小的MWE以复制我在主项目中看到的行为。我在Unity 3D中使用Single Pass Rendering和Windows Mixed Reality耳机。我有一个着色器，将其设置为新材料“ ppMaterial”，然后将其用于

void OnRenderImage(RenderTexture source, RenderTexture destination)
{
    Graphics.Blit(source, destination, ppMaterial);
}

在此MWE中，着色器仅应在屏幕边缘绘制圆形，因此我制作了一个简单的着色器：

Shader "Custom/ScreenShader" {
    Properties {
    }
    SubShader {
        Pass {
            CGPROGRAM
            #pragma fragment frag
            #pragma vertex vert
            #include "UnityCG.cginc"

            uniform sampler2D _MainTex;
            half4 _MainTex_ST;

            struct appdata
            {
                float4 vertex : POSITION;
                float2 uv : TEXCOORD0;
            };
            struct v2f
            {
                float4 vertex : SV_POSITION;
                float2 uv : TEXCOORD0;
                float4 screenPos : TEXCOORD1;
            };

            float getDist(float2 isIn, float2 pos2){
                return sqrt((isIn.x - pos2.x)*(isIn.x - pos2.x) + (isIn.y - pos2.y)*(isIn.y - pos2.y));
            }

            float4 NearBoundary(float2 isIn, v2f i)
            {
                float2 pos2 = float2(0.5,0.5);
                float2 pos3 = float2(0,0.5);
                float2 pos4 = float2(0.5,0.0);
                float dist2 = getDist(isIn, pos2);
                float dist3 = getDist(isIn, pos3);
                float dist4 = getDist(isIn, pos4);
                if(dist2<0.1){
                    return float4(0,0.5,0.5,1);
                }
                if(dist3.x<0.3){
                    return float4(0.5,0,0.5,1);
                }
                if(dist4.x<0.3){
                    return float4(0.5,0,0.5,1);
                }

                return tex2D(_MainTex, UnityStereoScreenSpaceUVAdjust(i.uv, _MainTex_ST));
            }

            v2f vert (appdata v)
            {
                v2f o;
                o.vertex = UnityObjectToClipPos(v.vertex);
                o.screenPos = ComputeScreenPos(o.vertex);
                o.uv = v.uv;
                return o;
            }

            half4 frag(v2f i) : SV_Target {
                float2 screenPos = i.screenPos;
                return NearBoundary(screenPos, i);
            }
            ENDCG
        }
    }
}

但这是行不通的，圆点不会分别在应有的中心和边界处绘制。如何获得每只眼睛在（0,1）范围内的正确屏幕坐标？

Answer 1

发现问题是提供坐标的相机设置了目标纹理，这似乎弄乱了坐标。然后，screenPos必须设置为

screenPos.x -= unity_StereoEyeIndex * 0.5;
screenPos.x *= 2;

还要插入

RenderTextureDescriptor d = XRSettings.eyeTextureDesc;
d.width = d.width / 2; // THIS DOES NOT MAKE SENSE
RenderTexture t = new RenderTexture(d);

在C＃代码以及设置中

uv.y = 1-uv.y

在着色器中，我终于摆脱了所有问题。

将其发布给其他有这些超级奇怪问题的人...

如何在Unity Shaders中为VR获取正确的屏幕坐标？

1 个答案: