Update subplot arrangement to support non-uniform grids

Summary: Previously, grids where the columns don't divide the number of plots evenly would error. Now, there'll just be a sparse last row.

Reviewed By: bottler

Differential Revision: D25069236

fbshipit-source-id: 9d2fd62f3d39bfebc07ce0a41718621fa69d6057

pytorch3d/vis/plotly_vis.py

@@ -692,10 +692,9 @@ def _gen_fig_with_subplots(batch_size: int, ncols: int, subplot_titles: List[str
     Returns:
         Plotly figure with ncols subplots per row, and batch_size subplots.
     """
-    if batch_size % ncols != 0:
-        msg = "ncols is invalid for the given mesh batch size."
-        warnings.warn(msg)
     fig_rows = batch_size // ncols
+    if batch_size % ncols != 0:
+        fig_rows += 1  # allow for non-uniform rows
     fig_cols = ncols
     fig_type = [{"type": "scene"}]
     specs = [fig_type * fig_cols] * fig_rows