shivaduke28

# BPM Detector プロトタイピング実装レポート

## 概要
RectorプロジェクトにおけるリアルタイムBPM検出機能のプロトタイプ実装を行った。当初は単純な低周波数レベル検出を使用していたが、スペクトラムフラックスベースのアプローチに移行し、より正確なBPM検出を実現した。

## 実装の経緯

### 1. 初期実装の問題点
- `audioInput.LevelLow`（時間領域の低周波数フィルタ）を使用
- BPMが150付近で張り付く問題が発生

shivaduke28

using System.Collections.Generic;
using UnityEditor;
using UnityEngine;
using VYaml.Annotations;
using VYaml.Serialization;

namespace Rector.Editor
{
    public static class VfxPropertyInfoReader
    {

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// This code is released under CC0 1.0 Universal (Public Domain Dedication).
// https://creativecommons.org/publicdomain/zero/1.0/

using UnityEngine;
using UnityEngine.UI;

namespace Rector.UI.Components
{
    public sealed class FrameView : Graphic
    {

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/*
MIT License

Copyright (c) 2024 shivaduke28

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is

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const cid = () => Math.floor(Math.random() * 1e4);

const delay = (t, f, a) => {
    let i = cid();
    let l = $.state.l ?? [];
    l.push([i, t, f.name, a]);
    $.state.l = l;
    return i;
};

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float3 SolidAngle(float3 p0, float3 p1, float3 p2)
{
    // edges
    float cos01 = dot(p0, p1);
    float cos12 = dot(p1, p2);
    float cos20 = dot(p2, p0);

    float sin01Inv = 1 / sqrt(1 - cos01 * cos01);
    float sin12Inv = 1 / sqrt(1 - cos12 * cos12);
    float sin20Inv = 1 / sqrt(1 - cos20 * cos20);

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#include "AutoLight.cginc"
#if defined(POINT)
// 1/range*range for Unity's PointLight
float UnityPointLightRangeInvSqr()
{
    float3 unitLS = float3(unity_WorldToLight._m00, unity_WorldToLight._m01, unity_WorldToLight._m02);
    return dot(unitLS, unitLS);
}

// https://forum.unity.com/threads/light-dist ance-in-shader.509306/#post-3326818

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using System;
using System.IO;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using UnityEditor;
using UnityEngine;

public static class LightingDataAssetReplacer
{

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Shader "Snell"
{
    Properties
    {
        _WaterColor ("Water Color", Color) = (0.2, 0.8, 1, 1)
        _Absorption("Absorption (sigma_a)", Color) = (0.3, 0.04, 0.01)
    }
    SubShader
    {
        Tags

shivaduke28

using System;
using UdonSharp;
using UnityEngine;
using VRC.SDKBase;
using VRC.Udon;

namespace TKMNY
{
    [UdonBehaviourSyncMode(BehaviourSyncMode.Manual)]
    public class GlobalMaterialChanger : UdonSharpBehaviour