Unity相机捕获图像的透明度调整方法咨询

Hey there! Since you're diving into an AR project in Unity and looking to tweak the transparency of your live camera feed—while also building up your Unity skills—here are two practical, easy-to-implement methods you can try right away:

This is the simplest approach, especially if you're working with a UI overlay for your AR feed:

• First, make sure your AR camera's live feed is being rendered to a texture (for AR Foundation, this is usually ARCameraManager.currentCameraTexture; for other SDKs, check their docs for the camera texture reference).
• Add a Canvas to your scene, then create a child GameObject under it and attach a RawImage component to it.
• Assign your camera's live texture to the RawImage's Texture field in the Inspector.
• To adjust transparency in real-time, create a small script like this and attach it to the RawImage GameObject:

using UnityEngine;
using UnityEngine.UI;

public class CameraTransparencyController : MonoBehaviour
{
    public RawImage cameraRawImage;
    [Range(0f, 1f)] public float transparency = 1f;

    void Update()
    {
        Color currentColor = cameraRawImage.color;
        currentColor.a = transparency;
        cameraRawImage.color = currentColor;
    }
}

• Drag your RawImage into the script's cameraRawImage field, then use the transparency slider in the Inspector to adjust opacity live.

If you want to modify the camera's direct render output (no UI layer), use a custom shader and post-processing:

• Create a new Unlit Shader (right-click in Project window > Create > Shader > Unlit Shader) and replace its code with this:

Shader "Custom/CameraTransparent"
{
    Properties
    {
        _MainTex ("Camera Feed", 2D) = "white" {}
        _Transparency ("Opacity", Range(0,1)) = 1.0
    }
    SubShader
    {
        Tags { "Queue"="Transparent" "RenderType"="Transparent" }
        LOD 100
        Blend SrcAlpha OneMinusSrcAlpha

        Pass
        {
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            #include "UnityCG.cginc"

            struct appdata
            {
                float4 vertex : POSITION;
                float2 uv : TEXCOORD0;
            };

            struct v2f
            {
                float2 uv : TEXCOORD0;
                float4 vertex : SV_POSITION;
            };

            sampler2D _MainTex;
            float4 _MainTex_ST;
            float _Transparency;

            v2f vert (appdata v)
            {
                v2f o;
                o.vertex = UnityObjectToClipPos(v.vertex);
                o.uv = TRANSFORM_TEX(v.uv, _MainTex);
                return o;
            }

            fixed4 frag (v2f i) : SV_Target
            {
                fixed4 col = tex2D(_MainTex, i.uv);
                col.a = _Transparency;
                return col;
            }
            ENDCG
        }
    }
}

• Create a new Material (right-click > Create > Material), set its shader to Custom/CameraTransparent.
• Attach this script to your AR camera to apply the shader effect:

using UnityEngine;

public class CameraShaderTransparency : MonoBehaviour
{
    public Material transparentMaterial;
    [Range(0f, 1f)] public float transparency = 1f;

    void OnRenderImage(RenderTexture source, RenderTexture destination)
    {
        transparentMaterial.SetFloat("_Transparency", transparency);
        Graphics.Blit(source, destination, transparentMaterial);
    }
}

• Drag your custom material into the script's transparentMaterial field, then use the slider to adjust the camera feed's opacity in real-time.

• If you're using AR Foundation, double-check that you're accessing the correct camera texture (use ARCameraManager to get it reliably).
• The RawImage method is great if you need to overlay other UI elements on top of the AR feed; the shader method is better for full-screen, seamless AR rendering.
• Test on your target device—some AR SDKs have specific camera rendering settings that might need adjustment to play nice with transparency.

内容的提问来源于stack exchange，提问作者JsF