diff --git a/nitransforms/resampling.py b/nitransforms/resampling.py
index e1ac1542..9de0d2d6 100644
--- a/nitransforms/resampling.py
+++ b/nitransforms/resampling.py
@@ -98,6 +98,7 @@ def apply(
     if data.ndim < transform.ndim:
         data = data[..., np.newaxis]
 
+    # For model-based nonlinear transforms, generate the corresponding dense field
     if hasattr(transform, "to_field") and callable(transform.to_field):
         targets = ImageGrid(spatialimage).index(
             _as_homogeneous(