投影贴花开发指南

using LCCCore;
using UnityEngine;

/// <summary>
/// Decal 贴花投影 —— 开发者最小使用示例。
///
/// 本脚本模拟"接入方脚本",只调用 LCCManager 的 public API,不触碰 SDK 内部。
/// 覆盖全部 7 个贴花 API:
///   基础投影(5)  SetDecalEnabled / SetDecalTexture / SetDecalProjection / SetDecalOpacity / SetDecalEdgeFade
///   遮挡剔除(2)  SetDecalOcclusion / SetDecalOcclusionSettings
///
/// 使用步骤:
///   1) 新建空 GameObject,挂上本脚本;
///   2) Inspector 里把场景中的 LCCManager 拖到 m_manager;
///   3) m_filePath 填一个有效 LCC 场景路径;
///   4) m_decalTexture 拖入要投影的图片(建议在导入设置里勾 Read/Write);
///   5) m_projector 拖入一个空物体当投影仪(留空则用本物体),它的 +Z 朝向即投影方向;
///   6) Play。场景加载完成后贴花自动开启,拖动投影仪即可实时看到贴花打在点云上。
///
/// 平台说明:贴花与遮挡剔除仅在 PC/Mac(URP)生效,移动端/VR 调用会被 SDK 忽略并打印 LogWarning。
/// </summary>
public class Decal : MonoBehaviour
{
    [Header("必填")]
    [Tooltip("场景中的 LCCManager 实例")]
    public LCCManager m_manager;
    [Tooltip("有效的 LCC 场景路径")]
    public string m_filePath;
    [Tooltip("要投影的贴花图片。RGB=颜色, A=贴花自身遮罩")]
    public Texture2D m_decalTexture;

    [Header("投影仪 (沿 +Z 方向投影)")]
    [Tooltip("投影仪位姿。留空则用本物体 transform")]
    public Transform m_projector;
    [Range(1f, 179f)] public float m_fov = 60f;
    [Tooltip("投影宽高比; <=0 时按贴花图片宽高比自动计算")]
    public float m_aspect = 0f;
    public float m_near = 0.1f;
    public float m_far = 100f;

    [Header("贴花外观")]
    [Range(0f, 1f)] public float m_opacity = 1.0f;
    [Range(0f, 0.5f)][Tooltip("边缘羽化宽度(UV 比例)。0 = 硬边")]
    public float m_edgeFade = 0.1f;
    [Tooltip("每帧刷新投影,便于运行时拖动投影仪 / 改参数看效果")]
    public bool m_updateEveryFrame = true;

    [Header("遮挡剔除 (仅 PC/Mac)")]
    [Tooltip("开启后被前方遮挡的背面/被挡点云不再被贴花染色(幻灯机效果),关闭则 X 光穿透")]
    public bool m_occlusion = false;
    [Range(0f, 1f)][Tooltip("opacity 阈值: 仅 opacity ≥ 此值的 splat 参与深度图,滤浮点/雾状点。0=全部参与")]
    public float m_occlusionCutoff = 0f;
    [Range(0f, 0.5f)][Tooltip("相对深度容差。过小→近面自遮挡; 过大→漏挡穿透。默认 0.05")]
    public float m_occlusionBias = 0.05f;
    [Range(0, 16)][Tooltip("方形足迹半径上限(px),去穿透漏染主旋钮。0=单纹素,默认 2")]
    public int m_occlusionFootprint = 2;
    [Tooltip("深度图分辨率(px, 2 的幂 256~4096)。调低补掠射面空洞,默认 1024")]
    public int m_occlusionResolution = 1024;

    // ── 运行时状态 ──
    private bool m_loaded;
    private bool m_lastOcclusion;
    private float m_lastCutoff = float.NaN;
    private float m_lastBias = float.NaN;
    private int m_lastFootprint = -1;
    private int m_lastResolution = -1;

    void Start()
    {
        if (m_manager == null || string.IsNullOrEmpty(m_filePath))
        {
            Debug.LogError("[DecalDemo] m_manager 或 m_filePath 未赋值。");
            enabled = false;
            return;
        }

        // 1) 初始化渲染管线为 PC 单场景编辑模式
        m_manager.SetPlatformType(PlatformType.PC);
        m_manager.SwitchRenderPass(ActiveRenderMode.SingleRender);
        m_manager.SetEditorMode(true);

        // 2) 加载点云场景,完成后再开启贴花(贴花是全局状态,场景就绪后设置最稳妥)
        var renderer = m_manager.GetRender(this.transform);
        Debug.Log($"[DecalDemo] 开始加载: {m_filePath}");
        renderer.Load(m_filePath,
            _ => { /* 进度回调,示例不使用 */ },
            OnSceneLoaded);
    }

    private void OnSceneLoaded()
    {
        Debug.Log("[DecalDemo] 加载完成,开启贴花投影。");

        // ── 基础投影:5 个 API ──
        m_manager.SetDecalTexture(m_decalTexture);   // 贴花内容
        m_manager.SetDecalOpacity(m_opacity);        // 整体不透明度
        m_manager.SetDecalEdgeFade(m_edgeFade);      // 边缘羽化
        ApplyProjection();                           // 投影仪位姿(内部 SetDecalProjection)
        m_manager.SetDecalEnabled(true);             // 开启贴花 (_DECAL keyword)

        // ── 遮挡剔除:2 个 API ── 必须在 ApplyProjection 之后(深度图需有效投影仪 VP)
        m_manager.SetDecalOcclusionSettings(BuildOcclusionSettings());
        m_manager.SetDecalOcclusion(m_occlusion);
        CacheOcclusionState();

        m_loaded = true;
    }

    /// <summary>
    /// 仅演示使用，实际项目中，为提高性能，不需要在 Update() 方法中每帧调用
    /// SetDecalProjection / SetDecalOpacity / SetDecalEdgeFade 等，仅在参数变化时调用相应 API 即可。
    /// </summary>
    void Update()
    {
        if (!m_loaded) return;

        // 遮挡开关运行时切换
        if (m_occlusion != m_lastOcclusion)
        {
            m_manager.SetDecalOcclusion(m_occlusion);
            m_lastOcclusion = m_occlusion;
        }

        // 遮挡质量参数任一变化 → 一次性下发结构体
        if (!Mathf.Approximately(m_occlusionCutoff, m_lastCutoff) ||
            !Mathf.Approximately(m_occlusionBias, m_lastBias) ||
            m_occlusionFootprint != m_lastFootprint ||
            m_occlusionResolution != m_lastResolution)
        {
            m_manager.SetDecalOcclusionSettings(BuildOcclusionSettings());
            CacheOcclusionState();
        }

        // 每帧刷新投影仪 / 外观,方便实时调试
        if (!m_updateEveryFrame) return;
        m_manager.SetDecalOpacity(m_opacity);
        m_manager.SetDecalEdgeFade(m_edgeFade);
        ApplyProjection();
    }

    /// <summary>用当前投影仪位姿与透视参数构建投影矩阵。</summary>
    private void ApplyProjection()
    {
        Transform p = m_projector != null ? m_projector : this.transform;
        float aspect = m_aspect > 0f
            ? m_aspect
            : (m_decalTexture != null ? (float)m_decalTexture.width / m_decalTexture.height : 1f);
        m_manager.SetDecalProjection(p.position, p.rotation, m_fov, aspect, m_near, m_far);
    }

    /// <summary>把 4 项遮挡参数汇集为结构体。</summary>
    private DecalOcclusionSettings BuildOcclusionSettings()
    {
        return new DecalOcclusionSettings
        {
            opacityCutoff  = m_occlusionCutoff,
            depthBias      = m_occlusionBias,
            footprintMaxPx = m_occlusionFootprint,
            resolution     = m_occlusionResolution,
        };
    }

    private void CacheOcclusionState()
    {
        m_lastOcclusion  = m_occlusion;
        m_lastCutoff     = m_occlusionCutoff;
        m_lastBias       = m_occlusionBias;
        m_lastFootprint  = m_occlusionFootprint;
        m_lastResolution = m_occlusionResolution;
    }

    // ── 便捷调试入口 (Inspector 右键) ──
    [ContextMenu("Decal On")]  private void DecalOn()  { m_manager?.SetDecalEnabled(true); }
    [ContextMenu("Decal Off")] private void DecalOff() { m_manager?.SetDecalEnabled(false); }
    [ContextMenu("Occlusion On")]  private void OcclusionOn()  { m_occlusion = true;  m_manager?.SetDecalOcclusion(true);  m_lastOcclusion = true; }
    [ContextMenu("Occlusion Off")] private void OcclusionOff() { m_occlusion = false; m_manager?.SetDecalOcclusion(false); m_lastOcclusion = false; }
}

// 返回值：void
public void SetDecalEnabled(bool enable)

m_manager.SetDecalEnabled(true);
m_manager.SetDecalTexture(decalTex);
m_manager.SetDecalProjection(projectorPos, projectorRot, 60f, 1.778f, 0.1f, 20f);

// 返回值：void
public void SetDecalTexture(Texture2D tex)

m_manager.SetDecalTexture(logoTex);

// 返回值：void
public void SetDecalProjection(Vector3 pos, Quaternion rot, float fov, float aspect, float near, float far)

m_manager.SetDecalProjection(new Vector3(0, 10, 0), Quaternion.Euler(90, 0, 0), 60f, 1.778f, 0.1f, 20f);

// 返回值：void
public void SetDecalOpacity(float opacity)

m_manager.SetDecalOpacity(0.8f);

// 返回值：void
public void SetDecalEdgeFade(float edgeFade)

m_manager.SetDecalEdgeFade(0.1f);

// 返回值：void
public void SetDecalOcclusion(bool enable)

m_manager.SetDecalOcclusion(true);

// 返回值：void
public void SetDecalOcclusionSettings(DecalOcclusionSettings settings)

m_manager.SetDecalOcclusionSettings(DecalOcclusionSettings.Default);
m_manager.SetDecalOcclusionSettings(new DecalOcclusionSettings {
    opacityCutoff = 0.1f,
    depthBias = 0.05f,
    footprintMaxPx = 2,
    resolution = 1024
});

public struct DecalOcclusionSettings {
    public float opacityCutoff;   // [0,1] splat 参与深度图的最低 opacity，默认 0（全部参与）
    public float depthBias;       // 相对深度容差比例，默认 0.05
    public int   footprintMaxPx;  // 方形足迹半径上限(px)，0~16，默认 2
    public int   resolution;      // 深度图分辨率(px，2 的幂，256~4096)，默认 1024

    public static DecalOcclusionSettings Default { get; } // cutoff=0, bias=0.05, footprint=2, resolution=1024
}