To fix VoxelNeXt training bugs in spconv 2.2 / 2.3 (#1313)

* VoxelNeXt

* Update .gitignore

* Update voxelnext_head.py

* Update spconv_utils.py

pcdet/models/dense_heads/voxelnext_head.py

@@ -5,7 +5,7 @@ from torch.nn.init import kaiming_normal_
 from ..model_utils import centernet_utils
 from ..model_utils import model_nms_utils
 from ...utils import loss_utils
-import spconv.pytorch as spconv
+from ...utils.spconv_utils import replace_feature, spconv
 import copy
 from easydict import EasyDict
 

pcdet/utils/spconv_utils.py

 from typing import Set
 
+import spconv
+if float(spconv.__version__[2:]) >= 2.2:
+    spconv.constants.SPCONV_USE_DIRECT_TABLE = False
+    
 try:
     import spconv.pytorch as spconv
 except: