kpconv_pytorch_mix3d.patch

diff --git a/datasets/SemanticKitti.py b/datasets/SemanticKitti.py
index 7a781e9..7d77bd4 100644
--- a/datasets/SemanticKitti.py
+++ b/datasets/SemanticKitti.py
@@ -418,6 +418,10 @@ class SemanticKittiDataset(PointCloudDataset):
         # Concatenate batch
         ###################
 
+        # MOVE TO CENTER FOR MIX3D
+        for p_i in range(len(p_list)):
+            p_list[p_i] -= p_list[p_i].mean(axis=0)
+
         stacked_points = np.concatenate(p_list, axis=0)
         features = np.concatenate(f_list, axis=0)
         labels = np.concatenate(l_list, axis=0)
@@ -427,6 +431,15 @@ class SemanticKittiDataset(PointCloudDataset):
         scales = np.array(s_list, dtype=np.float32)
         rots = np.stack(R_list, axis=0)
 
+        # roughly 20% non-merged
+        remainder = (stack_lengths.shape[0] - 2) // 4
+
+        if (stack_lengths.shape[0] - remainder) % 2 == 1:
+            remainder += 1
+
+        combined_lengths = np.sum(np.reshape(stack_lengths[:-remainder], (-1, 2)), axis=1)
+        stack_lengths = np.concatenate([combined_lengths, stack_lengths[-remainder:]]).astype(np.int32)
+
         # Input features (Use reflectance, input height or all coordinates)
         stacked_features = np.ones_like(stacked_points[:, :1], dtype=np.float32)
         if self.config.in_features_dim == 1:
@@ -1453,3 +1466,4 @@ def debug_class_w(dataset, loader):
             print(s)
             i += 1
 
+