# BEVFusion Camera配置灵活性分析与方案

**分析时间**: 2025-11-06  
**当前配置**: 6 Cameras + LiDAR (nuScenes标准)  
**目标**: 支持灵活的camera配置 (1-N个cameras)

---

## 📊 当前架构分析

### 现有Camera处理流程

```python
数据流:
  img: (B, N, C, H, W)  # N=6 cameras
    ↓
  Backbone: (B*N, C', H', W')  # 6个相机共享权重
    ↓
  Neck: (B*N, 256, H'', W'')
    ↓
  VTransform: (B, N, 80, D, H, W)  # 转到BEV空间
    ↓
  BEV Pooling: (B, 80*D, H, W)  # 聚合N个相机
    ↓
  Fuser + Decoder: (B, 512, H, W)
    ↓
  Task Heads
```

### 关键发现

1. ✅ **Camera数量N是动态的**：代码中N可以是任意值
2. ✅ **共享权重**：所有cameras共享同一个backbone/neck
3. ✅ **BEV Pooling自动聚合**：无论多少cameras，最终都pool到同一个BEV空间
4. ⚠️ **固定配置**：nuScenes硬编码为6个特定cameras

---

## 🎯 支持灵活Camera配置的方案

### 方案1: 简单动态配置 (最简单) ⭐

**适用场景**: 3-8个相似类型的cameras

**实现方式**: 
- 只需修改数据加载，模型无需改动
- 所有cameras共享权重
- BEV pooling自动适配

```yaml
# configs/custom/flexible_cameras.yaml

# 配置camera数量
num_cameras: 4  # 可以是1-N

camera_names: 
  - CAM_FRONT
  - CAM_FRONT_LEFT  
  - CAM_FRONT_RIGHT
  - CAM_BACK
  # 可以增减

# 模型配置 - 无需修改！
model:
  type: BEVFusion
  encoders:
    camera:
      backbone:
        type: SwinTransformer  # 权重共享
      neck:
        type: GeneralizedLSSFPN
      vtransform:
        type: DepthLSSTransform
        # BEV pooling会自动处理N个cameras
```

**优点**:
- ✅ 实现简单，无需修改模型代码
- ✅ 可以任意增减cameras
- ✅ 训练稳定

**缺点**:
- ⚠️ 所有cameras必须共享权重
- ⚠️ 无法针对特定camera优化

---

### 方案2: Camera-specific Adapter (推荐) ⭐⭐⭐

**适用场景**: 不同类型的cameras (如广角+长焦)

**核心思想**: 
- Backbone共享
- 每个camera有独立的adapter
- 适合heterogeneous cameras

```python
# mmdet3d/models/vtransforms/camera_aware_lss.py

class CameraAwareLSS(BaseTransform):
    """
    Camera感知的LSS Transform
    每个camera有独立的adapter处理特征
    """
    
    def __init__(
        self,
        in_channels: int,
        out_channels: int,
        num_cameras: int = 6,  # 动态camera数量
        camera_types: list = None,  # ['wide', 'tele', 'wide', ...]
        **kwargs
    ):
        super().__init__(in_channels, out_channels, **kwargs)
        
        # 为每个camera创建lightweight adapter
        self.camera_adapters = nn.ModuleList([
            nn.Sequential(
                nn.Conv2d(in_channels, in_channels, 3, 1, 1),
                nn.BatchNorm2d(in_channels),
                nn.ReLU(inplace=True),
                nn.Conv2d(in_channels, in_channels, 1),
            ) for _ in range(num_cameras)
        ])
        
        # Camera类型embedding (可选)
        self.use_camera_embedding = camera_types is not None
        if self.use_camera_embedding:
            unique_types = list(set(camera_types))
            self.camera_type_embed = nn.Embedding(
                len(unique_types), 
                in_channels
            )
            self.type_to_id = {t: i for i, t in enumerate(unique_types)}
        
        # 参数量: num_cameras × (in_channels² × 9 + in_channels²)
        # 示例: 6 × (256² × 10) ≈ 4M参数
    
    def get_cam_feats(self, x, mats_dict):
        """
        Args:
            x: (B, N, C, fH, fW) - N个cameras的特征
            mats_dict: camera矩阵
        """
        B, N, C, fH, fW = x.shape
        
        # 为每个camera应用adapter
        adapted_features = []
        for i in range(N):
            cam_feat = x[:, i]  # (B, C, fH, fW)
            
            # Camera-specific adapter
            cam_feat = self.camera_adapters[i](cam_feat)
            
            # (可选) 添加camera类型embedding
            if self.use_camera_embedding:
                cam_type_id = self.type_to_id[self.camera_types[i]]
                type_embed = self.camera_type_embed(
                    torch.tensor(cam_type_id).to(cam_feat.device)
                )
                cam_feat = cam_feat + type_embed.view(1, -1, 1, 1)
            
            adapted_features.append(cam_feat)
        
        # 重新组合
        x = torch.stack(adapted_features, dim=1)  # (B, N, C, fH, fW)
        
        # 继续LSS处理
        return super().get_cam_feats(x, mats_dict)
```

**配置示例**:

```yaml
model:
  encoders:
    camera:
      vtransform:
        type: CameraAwareLSS
        num_cameras: 4
        camera_types: ['wide', 'tele', 'wide', 'wide']
        in_channels: 256
        out_channels: 80
```

**优点**:
- ✅ 每个camera有独立处理能力
- ✅ 参数增加不多 (~4M)
- ✅ 可以适配不同类型cameras
- ✅ 向后兼容

**缺点**:
- ⚠️ 需要修改vtransform代码
- ⚠️ 训练时间略增加 (~5%)

---

### 方案3: Mixture of Experts (MoE) ⭐⭐⭐⭐

**适用场景**: 多种camera类型，需要最优性能

**核心思想**:
- 为不同camera类型创建专家网络
- Router动态选择experts
- 可以根据camera属性自动路由

```python
# mmdet3d/models/modules/camera_moe.py

class CameraMoE(nn.Module):
    """
    Camera Mixture of Experts
    
    根据camera类型动态选择expert
    """
    
    def __init__(
        self,
        in_channels: int,
        num_experts: int = 3,  # 3种expert: wide, tele, fisheye
        expert_capacity: int = 256,
        **kwargs
    ):
        super().__init__()
        
        # 创建多个experts
        self.experts = nn.ModuleList([
            CameraExpert(in_channels, expert_capacity)
            for _ in range(num_experts)
        ])
        
        # Router: 决定使用哪个expert
        self.router = nn.Sequential(
            nn.AdaptiveAvgPool2d(1),  # Global pooling
            nn.Flatten(),
            nn.Linear(in_channels, num_experts),
            nn.Softmax(dim=-1)
        )
        
        # Camera属性encoder (FOV, focal length, etc.)
        self.camera_attr_encoder = nn.Sequential(
            nn.Linear(4, 64),  # [FOV, focal_x, focal_y, type_id]
            nn.ReLU(),
            nn.Linear(64, in_channels),
        )
    
    def forward(self, x, camera_attrs):
        """
        Args:
            x: (B, N, C, H, W) - N个cameras
            camera_attrs: (B, N, 4) - [FOV, focal_x, focal_y, type_id]
        
        Returns:
            (B, N, C, H, W) - processed features
        """
        B, N, C, H, W = x.shape
        
        outputs = []
        for i in range(N):
            cam_feat = x[:, i]  # (B, C, H, W)
            cam_attr = camera_attrs[:, i]  # (B, 4)
            
            # 1. 编码camera属性
            attr_embed = self.camera_attr_encoder(cam_attr)  # (B, C)
            attr_embed = attr_embed.unsqueeze(-1).unsqueeze(-1)  # (B, C, 1, 1)
            
            # 2. Router选择expert
            router_input = cam_feat + attr_embed
            expert_weights = self.router(router_input)  # (B, num_experts)
            
            # 3. 组合多个experts
            expert_outputs = []
            for expert in self.experts:
                expert_out = expert(cam_feat)
                expert_outputs.append(expert_out)
            
            # 加权组合: (B, num_experts, C, H, W)
            expert_outputs = torch.stack(expert_outputs, dim=1)
            
            # 应用router权重
            expert_weights = expert_weights.view(B, -1, 1, 1, 1)
            cam_output = (expert_outputs * expert_weights).sum(dim=1)
            
            outputs.append(cam_output)
        
        return torch.stack(outputs, dim=1)  # (B, N, C, H, W)


class CameraExpert(nn.Module):
    """单个Expert网络"""
    
    def __init__(self, in_channels, out_channels):
        super().__init__()
        self.conv = nn.Sequential(
            nn.Conv2d(in_channels, out_channels, 3, 1, 1),
            nn.BatchNorm2d(out_channels),
            nn.ReLU(inplace=True),
            nn.Conv2d(out_channels, in_channels, 3, 1, 1),
            nn.BatchNorm2d(in_channels),
        )
        self.shortcut = nn.Identity()
    
    def forward(self, x):
        return F.relu(self.conv(x) + self.shortcut(x))
```

**配置示例**:

```yaml
model:
  encoders:
    camera:
      backbone:
        type: SwinTransformer
        # 共享backbone
      
      neck:
        type: GeneralizedLSSFPN
        # 添加MoE
        use_camera_moe: true
        moe_config:
          num_experts: 3  # wide, tele, fisheye
          expert_capacity: 256
      
      vtransform:
        type: DepthLSSTransform

# 数据配置
camera_attributes:
  CAM_FRONT:
    type: 'wide'
    fov: 120.0
    focal_length: [1266.0, 1266.0]
  
  CAM_FRONT_TELE:
    type: 'tele'
    fov: 30.0
    focal_length: [2532.0, 2532.0]
  
  CAM_FRONT_LEFT:
    type: 'wide'
    fov: 120.0
    focal_length: [1266.0, 1266.0]
```

**优点**:
- ✅ 最强的表达能力
- ✅ 自动学习不同camera的最优处理
- ✅ 支持高度异质化的cameras
- ✅ 可以融合camera属性信息

**缺点**:
- ⚠️ 实现复杂度高
- ⚠️ 参数增加较多 (~10M)
- ⚠️ 训练时间增加 (~10-15%)
- ⚠️ 需要足够数据训练router

---

### 方案4: Per-Camera Attention (最灵活) ⭐⭐⭐⭐⭐

**适用场景**: 任意数量和类型的cameras

**核心思想**:
- 让模型学习每个camera的重要性
- Cross-camera attention
- 动态融合不同cameras

```python
# mmdet3d/models/modules/camera_attention.py

class MultiCameraAttentionFusion(nn.Module):
    """
    多相机注意力融合
    
    特点:
      - 支持任意数量cameras (1-N)
      - 自动学习camera间的关系
      - 位置感知的camera融合
    """
    
    def __init__(
        self,
        in_channels: int,
        num_cameras: int = 6,  # 可变
        use_camera_position: bool = True,  # 使用camera位置信息
        use_cross_attention: bool = True,  # camera间交互
    ):
        super().__init__()
        
        self.num_cameras = num_cameras
        self.use_camera_position = use_camera_position
        
        # Camera位置编码 (相对vehicle的位置)
        if use_camera_position:
            self.position_encoder = nn.Sequential(
                nn.Linear(6, 128),  # [x, y, z, roll, pitch, yaw]
                nn.ReLU(),
                nn.Linear(128, in_channels),
            )
        
        # Self-attention for each camera
        self.self_attention = nn.MultiheadAttention(
            embed_dim=in_channels,
            num_heads=8,
            dropout=0.1,
        )
        
        # Cross-camera attention
        if use_cross_attention:
            self.cross_attention = nn.MultiheadAttention(
                embed_dim=in_channels,
                num_heads=8,
                dropout=0.1,
            )
        
        # Camera importance weighting
        self.camera_weight_net = nn.Sequential(
            nn.Linear(in_channels, in_channels // 4),
            nn.ReLU(),
            nn.Linear(in_channels // 4, 1),
            nn.Sigmoid(),
        )
    
    def forward(self, x, camera_positions=None):
        """
        Args:
            x: (B, N, C, H, W) - N个cameras
            camera_positions: (B, N, 6) - 每个camera的位置[x,y,z,r,p,y]
        
        Returns:
            (B, N, C, H, W) - attention-enhanced features
        """
        B, N, C, H, W = x.shape
        
        # Reshape for attention: (N, B*H*W, C)
        x_flat = x.permute(1, 0, 3, 4, 2).reshape(N, B*H*W, C)
        
        # 1. 添加camera位置编码
        if self.use_camera_position and camera_positions is not None:
            pos_embed = self.position_encoder(camera_positions)  # (B, N, C)
            pos_embed = pos_embed.permute(1, 0, 2).unsqueeze(2)  # (N, B, 1, C)
            pos_embed = pos_embed.expand(-1, -1, H*W, -1).reshape(N, B*H*W, C)
            x_flat = x_flat + pos_embed
        
        # 2. Self-attention (within each camera)
        x_self, _ = self.self_attention(x_flat, x_flat, x_flat)
        
        # 3. Cross-camera attention (between cameras)
        if hasattr(self, 'cross_attention'):
            # Query from each camera, Key/Value from all cameras
            x_cross = []
            for i in range(N):
                query = x_self[i:i+1]  # (1, B*H*W, C)
                key_value = x_self     # (N, B*H*W, C)
                attended, attn_weights = self.cross_attention(
                    query, key_value, key_value
                )
                x_cross.append(attended)
            
            x_attended = torch.cat(x_cross, dim=0)  # (N, B*H*W, C)
        else:
            x_attended = x_self
        
        # 4. 计算每个camera的重要性权重
        # Global pooling for each camera
        x_pooled = x_attended.mean(dim=1)  # (N, C)
        camera_weights = self.camera_weight_net(x_pooled)  # (N, 1)
        
        # 应用权重
        camera_weights = camera_weights.view(N, 1, 1).expand(-1, B*H*W, C)
        x_weighted = x_attended * camera_weights
        
        # Reshape back: (N, B*H*W, C) -> (B, N, C, H, W)
        output = x_weighted.reshape(N, B, H, W, C).permute(1, 0, 4, 2, 3)
        
        return output
```

**集成到BEVFusion**:

```python
# mmdet3d/models/fusion_models/bevfusion.py (修改)

def extract_camera_features(self, img, ...):
    B, N, C, H, W = img.shape
    
    # Backbone (共享)
    x = img.view(B * N, C, H, W)
    x = self.encoders["camera"]["backbone"](x)
    x = self.encoders["camera"]["neck"](x)
    
    # Reshape: (B*N, C', H', W') -> (B, N, C', H', W')
    _, C_out, H_out, W_out = x.shape
    x = x.view(B, N, C_out, H_out, W_out)
    
    # ✨ Multi-camera attention fusion
    if hasattr(self, 'camera_attention'):
        x = self.camera_attention(x, camera_positions)
    
    # VTransform
    x = self.encoders["camera"]["vtransform"](x, ...)
    
    return x
```

**优点**:
- ✅ 最灵活，支持任意N个cameras
- ✅ 自动学习camera重要性
- ✅ camera间信息交互
- ✅ 位置感知融合
- ✅ 可以处理missing cameras (动态N)

**缺点**:
- ⚠️ 实现复杂
- ⚠️ 参数较多 (~8M)
- ⚠️ 计算开销 (+15-20ms)

---

### 方案5: Sparse MoE (高效版) ⭐⭐⭐⭐

**适用场景**: 大量cameras (>6)，需要效率

**核心思想**:
- 每次只激活top-K experts
- 降低计算开销
- 适合异构camera系统

```python
# mmdet3d/models/modules/sparse_camera_moe.py

class SparseCameraMoE(nn.Module):
    """
    稀疏Camera MoE
    
    对于每个sample，只使用top-K个experts
    大幅降低计算开销
    """
    
    def __init__(
        self,
        in_channels: int,
        num_experts: int = 8,  # 支持8种camera类型
        num_active_experts: int = 3,  # 每次只用3个
        expert_hidden_dim: int = 256,
    ):
        super().__init__()
        
        self.num_experts = num_experts
        self.num_active_experts = num_active_experts
        
        # 创建experts
        self.experts = nn.ModuleList([
            nn.Sequential(
                nn.Conv2d(in_channels, expert_hidden_dim, 3, 1, 1),
                nn.BatchNorm2d(expert_hidden_dim),
                nn.ReLU(),
                nn.Conv2d(expert_hidden_dim, in_channels, 3, 1, 1),
                nn.BatchNorm2d(in_channels),
            ) for _ in range(num_experts)
        ])
        
        # Gating network: 选择哪些experts
        self.gate = nn.Sequential(
            nn.AdaptiveAvgPool2d(1),
            nn.Flatten(),
            nn.Linear(in_channels, num_experts),
        )
        
        # Load balancing auxiliary loss
        self.load_balancing_loss_weight = 0.01
    
    def forward(self, x, camera_types=None):
        """
        Args:
            x: (B, N, C, H, W)
            camera_types: (B, N) - camera type IDs
        
        Returns:
            output: (B, N, C, H, W)
            aux_loss: load balancing loss
        """
        B, N, C, H, W = x.shape
        
        outputs = []
        gate_scores_all = []
        
        for i in range(N):
            cam_feat = x[:, i]  # (B, C, H, W)
            
            # Gate scores: 选择experts
            gate_scores = self.gate(cam_feat)  # (B, num_experts)
            gate_scores_all.append(gate_scores)
            
            # Top-K selection
            top_k_scores, top_k_indices = torch.topk(
                gate_scores, 
                self.num_active_experts, 
                dim=-1
            )  # (B, K)
            
            # Normalize top-K scores
            top_k_scores = F.softmax(top_k_scores, dim=-1)
            
            # 只计算top-K experts
            expert_outs = []
            for b in range(B):
                sample_out = torch.zeros_like(cam_feat[b:b+1])
                
                for k in range(self.num_active_experts):
                    expert_idx = top_k_indices[b, k]
                    expert_weight = top_k_scores[b, k]
                    
                    expert_result = self.experts[expert_idx](cam_feat[b:b+1])
                    sample_out += expert_result * expert_weight
                
                expert_outs.append(sample_out)
            
            cam_output = torch.cat(expert_outs, dim=0)
            outputs.append(cam_output)
        
        output = torch.stack(outputs, dim=1)  # (B, N, C, H, W)
        
        # Load balancing loss (鼓励均匀使用experts)
        gate_scores_all = torch.stack(gate_scores_all, dim=1)  # (B, N, num_experts)
        gate_mean = gate_scores_all.mean(dim=[0, 1])  # (num_experts,)
        load_balance_loss = (gate_mean.std() ** 2) * self.load_balancing_loss_weight
        
        return output, load_balance_loss
```

**配置示例**:

```yaml
model:
  encoders:
    camera:
      neck:
        type: GeneralizedLSSFPN
        use_sparse_moe: true
        moe_config:
          num_experts: 8
          num_active_experts: 3  # 每次只用3个
          expert_hidden_dim: 256

# 支持多种camera类型
camera_configs:
  - type: 'wide'        # expert 0
  - type: 'tele'        # expert 1
  - type: 'fisheye'     # expert 2
  - type: 'ultra_wide'  # expert 3
  # ... 可以定义更多
```

**优点**:
- ✅ 支持大量camera类型 (8+)
- ✅ 计算高效 (只用top-K)
- ✅ 自动学习expert选择
- ✅ Load balancing确保训练稳定

**缺点**:
- ⚠️ 实现最复杂
- ⚠️ 需要调试router training
- ⚠️ 需要足够多样的camera数据

---

## 🔍 方案对比

| 方案 | 灵活性 | 复杂度 | 参数量 | 计算开销 | 推荐场景 |
|------|--------|--------|--------|----------|---------|
| **简单动态** | ⭐⭐ | ⭐ | +0 | +0% | 3-6个相似cameras |
| **Camera Adapter** | ⭐⭐⭐ | ⭐⭐ | +4M | +5% | 不同类型cameras (4-6个) |
| **MoE** | ⭐⭐⭐⭐ | ⭐⭐⭐ | +10M | +20% | 多种camera类型 |
| **Per-Camera Attn** | ⭐⭐⭐⭐⭐ | ⭐⭐⭐ | +8M | +15% | 任意配置，最优性能 |
| **Sparse MoE** | ⭐⭐⭐⭐⭐ | ⭐⭐⭐⭐ | +12M | +10% | 大量cameras (>6) |

---

## 💡 针对您的BEVFusion项目建议

### 当前状态分析

您现在的配置:
- ✅ 6 cameras (nuScenes标准)
- ✅ 1 LiDAR
- ✅ Task-specific GCA已实现

### 建议方案

**短期 (当前训练完成后)**:

**推荐: 方案2 - Camera Adapter** 

理由:
1. ✅ 实现简单，风险低
2. ✅ 参数开销小 (~4M)
3. ✅ 与Task-GCA架构兼容
4. ✅ 可以先支持4-8个cameras
5. ✅ 2-3天即可实现

实施步骤:
```python
# Step 1: 创建CameraAwareLSS类
# Step 2: 在配置文件中启用
# Step 3: 从现有checkpoint fine-tune
# Step 4: 测试不同camera数量 (4, 5, 6, 8)
```

**中期 (如需更强性能)**:

**推荐: 方案4 - Per-Camera Attention**

理由:
1. ✅ 最佳性能
2. ✅ 灵活性最高
3. ✅ 可以与Task-GCA结合
4. ✅ 学术价值高

组合架构:
```
Camera Input (N个)
  ↓
Shared Backbone (Swin Transformer)
  ↓
Multi-Camera Attention Fusion  ← 新增
  ↓
VTransform (LSS)
  ↓
Fuser (Camera + LiDAR)
  ↓
Decoder
  ↓
Task-specific GCA  ← 已有
  ├─ Detection GCA
  └─ Segmentation GCA
  ↓
Task Heads
```

---

## 🚀 实施建议

### 阶段1: 基础灵活化 (1周)

```python
# 1. 修改数据加载支持动态camera数量
# mmdet3d/datasets/pipelines/loading.py

@PIPELINES.register_module()
class LoadMultiViewImageFromFiles:
    def __init__(self, to_float32=False, camera_names=None):
        self.to_float32 = to_float32
        self.camera_names = camera_names or [
            'CAM_FRONT', 'CAM_FRONT_RIGHT', 'CAM_FRONT_LEFT',
            'CAM_BACK', 'CAM_BACK_LEFT', 'CAM_BACK_RIGHT'
        ]
        self.num_cameras = len(self.camera_names)
    
    def __call__(self, results):
        # 只加载指定的cameras
        images = []
        for cam_name in self.camera_names:
            if cam_name in results['cams']:
                img_path = results['cams'][cam_name]['data_path']
                images.append(Image.open(img_path))
        
        results['img'] = images
        results['num_cameras'] = len(images)
        return results
```

### 阶段2: Camera Adapter (1周)

```bash
# 实现camera-specific adapter
vim mmdet3d/models/vtransforms/camera_aware_lss.py

# 配置文件
vim configs/nuscenes/det/transfusion/secfpn/camera+lidar/swint_v0p075/multitask_camera_aware.yaml

# 测试
python tools/train.py configs/.../multitask_camera_aware.yaml \
  --load_from runs/run-326653dc-2334d461/epoch_5.pth \
  --data.samples_per_gpu 1
```

### 阶段3: MoE/Attention (可选, 2周)

```bash
# 如果需要最强性能，实现attention或MoE
vim mmdet3d/models/modules/camera_attention.py
vim mmdet3d/models/modules/camera_moe.py
```

---

## 📊 预期效果

### 方案2 (Camera Adapter)

```
配置灵活性:
  ✅ 支持 1-8 个cameras
  ✅ 每个camera独立处理
  ✅ 自动适配不同FOV

性能影响:
  参数: +4M (110M → 114M)
  速度: +5% (2.66s → 2.79s/iter)
  精度: +1-2% (adapter优化)

训练:
  从epoch_5.pth开始: 需要3-5 epochs适应
  总时间: ~2天
```

### 方案4 (Per-Camera Attention)

```
配置灵活性:
  ✅ 支持任意数量cameras
  ✅ Camera间信息交互
  ✅ 动态camera权重

性能影响:
  参数: +8M (110M → 118M)
  速度: +15% (2.66s → 3.06s/iter)
  精度: +2-4% (attention优化)

训练:
  从epoch_5.pth开始: 需要5-8 epochs
  总时间: ~3-4天
```

---

## 🎯 具体实现roadmap

### 如果您现在就需要

**推荐路径: Camera Adapter方案**

```
Week 1: 实现 (等待当前训练完成期间)
  Day 1: 设计CameraAwareLSS接口
  Day 2-3: 实现camera adapter模块
  Day 4: 编写配置文件
  Day 5: 单元测试

Week 2: 训练 (Epoch 20完成后)
  Day 1: 从epoch_20.pth开始fine-tune
  Day 2-3: 训练Camera Adapter (5 epochs)
  Day 4: 评估不同camera配置
  Day 5: 性能对比和文档

Week 3: 优化 (可选)
  Day 1-3: 升级到Attention方案
  Day 4-5: 进一步调优
```

---

## 📝 代码模板

我可以立即为您创建:

1. **CameraAwareLSS实现** (`mmdet3d/models/vtransforms/camera_aware_lss.py`)
2. **配置文件模板** (`configs/.../multitask_camera_aware.yaml`)
3. **测试脚本** (`tools/test_camera_configs.py`)
4. **文档** (`docs/CAMERA_FLEXIBILITY_GUIDE.md`)

---

## ✅ 总结建议

### 对于您的项目

**立即可做**:
1. ✅ 简单修改：支持4-8个cameras（修改数据加载即可）
2. ✅ Camera Adapter：2周实现，性能提升1-2%
3. ✅ 与Task-GCA兼容：可以叠加使用

**进阶方案**:
1. 🎯 Per-Camera Attention：如需最优性能
2. 🎯 Sparse MoE：如果camera类型很多 (>8)

**我的建议**:
- 先完成当前Task-GCA训练 (Epoch 20)
- 评估性能后，如果需要进一步提升camera处理
- 实现Camera Adapter方案 (ROI最高)
- 如果效果好，再考虑升级到Attention

**需要我现在开始实现Camera Adapter代码吗？**