Transparency in Camera RenderTexture

Question

In my Unity project, I'm working on rendering a view from a Camera to a Texture2D. I have created a RenderTexture to capture the Camera's output and then copied it to a Texture2D. However, I'm encountering an issue where I need the resulting image to have a transparent background. The only solution I have found so far is to set the Camera's background to transparent. However, I still have to specify a color, and this color becomes visible in all semi-transparent areas of the image.

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In the white frame, you can see the final result obtained in the RenderTexture

Do you happen to know of any alternative methods to obtain a camera image with proper transparency?

Updated

Thank @mrVentures for the suggestion; I tried implementing it. A RenderTexture accumulates the image without clearing, so before copying it, it needs to be cleared and rendered for a single frame. Here's my code if anyone needs it.

public void clearTexture(RenderTexture texture) {
    RenderTexture.active = texture;
    GL.Clear(true, true, Color.clear);
    RenderTexture.active = null;

    // texture.Release();  — another option
}

public Texture2D getTextureFromCamera(Camera camera) {
    RenderTexture rt = camera.targetTexture;
    clearTexture(rt);
    viewCamera.Render();
    
    Texture2D tex = new Texture2D(rt.width, rt.height, TextureFormat.RGBA32, false);
    RenderTexture.active = rt;
    tex.ReadPixels(new Rect(0, 0, rt.width, rt.height), 0, 0);
    tex.Apply();
    RenderTexture.active = null;

    return tex;
}

Unfortunately, the result turned out exactly the same as when I had CameraClearFlags.Color with a black transparent background. As a result, the black semi-transparent shadows become even darker, and bright colors acquire a dark halo. This is far from the desired outcome.

Do you have any other ideas I could try? I had the thought of obtaining the alpha channel separately and somehow baking the texture so that the semi-transparent areas of the image would be opaque. However, I have no idea how to accomplish that.

Answer 1

Clear flags docs: https://docs.unity3d.com/ScriptReference/Camera-

CameraClearFlags.Nothing seems like what you want.