better handling of weight loading for spconv1 vs 2

pcdet/__init__.py

 import subprocess
 from pathlib import Path
 
-from packaging import version as p_version
-
 from .version import __version__
 
 __all__ = [
@@ -24,7 +22,3 @@ script_version = get_git_commit_number()
 
 if script_version not in __version__:
     __version__ = __version__ + '+py%s' % script_version
-
-
-def v1_is_lower_than_v2(version1: str, version2: str):
-    return p_version.parse(version1) < p_version.parse(version2)

pcdet/models/detectors/detector3d_template.py

@@ -3,7 +3,6 @@ import os
 import torch
 import torch.nn as nn
 
-from ... import v1_is_lower_than_v2
 from ...ops.iou3d_nms import iou3d_nms_utils
 from ...spconv_utils import find_all_spconv_keys
 from .. import backbones_2d, backbones_3d, dense_heads, roi_heads
@@ -327,17 +326,16 @@ class Detector3DTemplate(nn.Module):
             gt_iou = box_preds.new_zeros(box_preds.shape[0])
         return recall_dict
 
-    def _load_state_dict(self, model_state_disk, version, *, strict=True):
+    def _load_state_dict(self, model_state_disk, *, strict=True):
         state_dict = self.state_dict()  # local cache of state_dict
 
-        version = version.split("+")[1]
         spconv_keys = find_all_spconv_keys(self)
 
         update_model_state = {}
         for key, val in model_state_disk.items():
-            if version is None or v1_is_lower_than_v2(version, "0.4.0"):  # spconv change
-                if key in spconv_keys:
-                    val = val.transpose(-1, -2).contiguous()
+            if key in spconv_keys and key in state_dict and state_dict[key].shape != val.shape:
+                # with different spconv versions, we need to adapt weight shapes for spconv blocks
+                val = val.transpose(-1, -2).contiguous()
 
             if key in state_dict and state_dict[key].shape == val.shape:
                 update_model_state[key] = val
@@ -363,7 +361,7 @@ class Detector3DTemplate(nn.Module):
         if version is not None:
             logger.info('==> Checkpoint trained from version: %s' % version)
 
-        state_dict, update_model_state = self._load_state_dict(model_state_disk, version, strict=False)
+        state_dict, update_model_state = self._load_state_dict(model_state_disk, strict=False)
 
         for key in state_dict:
             if key not in update_model_state:
@@ -381,8 +379,7 @@ class Detector3DTemplate(nn.Module):
         epoch = checkpoint.get('epoch', -1)
         it = checkpoint.get('it', 0.0)
 
-        version = checkpoint.get("version", None)
-        self._load_state_dict(checkpoint['model_state'], version, strict=True)
+        self._load_state_dict(checkpoint['model_state'], strict=True)
 
         if optimizer is not None:
             if 'optimizer_state' in checkpoint and checkpoint['optimizer_state'] is not None: