从半透明平面投射阴影

using UnityEngine;

public class TransparentShadowCaster : MonoBehaviour
{
    public Material transparentMaterial; // 半透明材质
    public bool castShadows = true; // 是否投射阴影

    void Start()
    {
        if (transparentMaterial != null)
        {
            transparentMaterial.SetFloat("_Opacity", 0.5f); // 设置透明度
            transparentMaterial.SetInt("_SrcBlend", (int)UnityEngine.Rendering.BlendMode.SrcAlpha);
            transparentMaterial.SetInt("_DstBlend", (int)UnityEngine.Rendering.BlendMode.OneMinusSrcAlpha);
        }
    }

    void Update()
    {
        Renderer rend = GetComponent<Renderer>();
        if (rend != null)
        {
            rend.shadowCastingMode = castShadows ? UnityEngine.Rendering.ShadowCastingMode.On : UnityEngine.Rendering.ShadowCastingMode.Off;
        }
    }
}