[Fix] #448 Clamp 3D votes projections to image boundaries (#463)

* Clamp 2D Projection of 3D Votes to Image Boundaries

* 'lint'

* 'lint;

* lint
Co-authored-by: Yezhen Cong <52420115+THU17cyz@users.noreply.github.com>

mmdet3d/models/fusion_layers/vote_fusion.py

@@ -196,6 +196,10 @@ class VoteFusion(nn.Module):
             img_flatten /= 255.
 
             # take the normalized pixel value as texture cue
+            uv_rescaled[:, 0] = torch.clamp(uv_rescaled[:, 0].round(), 0,
+                                            img_shape[1] - 1)
+            uv_rescaled[:, 1] = torch.clamp(uv_rescaled[:, 1].round(), 0,
+                                            img_shape[0] - 1)
             uv_flatten = uv_rescaled[:, 1].round() * \
                 img_shape[1] + uv_rescaled[:, 0].round()
             uv_expanded = uv_flatten.unsqueeze(0).expand(3, -1).long()