Add h5py/imageio deps, cmap completion, quick-start guide, simplify imports

- Add h5py, imageio, imageio-ffmpeg to required deps in pyproject.toml
- Remove optional h5py guard in silo_reader.py (now always installed)
- Import imageio.v2 at module level in renderer.py (hard dep, no fallback)
- Add --cmap tab completion with 17 colormaps to commands.py
- Add quick-start guide in viz.py when no action flags are specified

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: sbryngelson

toolchain/mfc/cli/commands.py

@@ -911,6 +911,12 @@
             type=str,
             default=None,
             metavar="CMAP",
+            completion=Completion(type=CompletionType.CHOICES, choices=[
+                "viridis", "plasma", "magma", "inferno", "cividis",
+                "hot", "cool", "jet", "rainbow", "turbo",
+                "RdBu", "seismic", "bwr", "coolwarm",
+                "gray", "bone", "pink",
+            ]),
         ),
         Argument(
             name="vmin",

toolchain/mfc/viz/renderer.py

@@ -10,6 +10,9 @@
 import tempfile
 
 import numpy as np
+
+import imageio.v2 as imageio
+
 import matplotlib
 matplotlib.use('Agg')
 import matplotlib.pyplot as plt  # pylint: disable=wrong-import-position
@@ -234,12 +237,6 @@ def render_mp4(varname, steps, output, fps=10,  # pylint: disable=too-many-argum
     frame_files = sorted(f for f in os.listdir(viz_dir) if f.endswith('.png'))
 
     success = False
-    try:
-        import imageio  # pylint: disable=import-outside-toplevel
-    except ImportError:
-        print("imageio is not installed. Install it with: pip install imageio imageio-ffmpeg")
-        return False
-
     try:
         imageio.mimwrite(
             output,

toolchain/mfc/viz/silo_reader.py

@@ -7,39 +7,22 @@
 Actual data lives in numbered datasets under the ``.silo/`` group.
 
 This reader uses h5py to navigate that structure.
-
-Requires: h5py (optional dependency).
 """
 
 import os
 import warnings
 from typing import Dict, List, Optional, Tuple
 
+import h5py
 import numpy as np
 
 from .reader import AssembledData, ProcessorData, assemble_from_proc_data
 
-try:
-    import h5py
-
-    HAS_H5PY = True
-except ImportError:
-    HAS_H5PY = False
-
 # Silo type constants (from silo.h)
 _DB_QUADMESH = 130
 _DB_QUADVAR = 501
 
 
-def _check_h5py():
-    if not HAS_H5PY:
-        raise ImportError(
-            "h5py is required to read Silo-HDF5 files.\n"
-            "Install it with: pip install h5py\n"
-            "Or re-run post_process with format=2 to produce binary output."
-        )
-
-
 
 def _resolve_path(h5file, path_bytes):
     """Resolve a silo internal path (e.g. b'/.silo/#000003') and return its data as a numpy array."""
@@ -60,7 +43,6 @@ def read_silo_file(  # pylint: disable=too-many-locals
     Returns:
         ProcessorData with grid coordinates and variable arrays.
     """
-    _check_h5py()
 
     with h5py.File(path, "r") as f:
         # --- locate the mesh ------------------------------------------------
@@ -146,7 +128,6 @@ def assemble_silo(
     """
     Read and assemble multi-processor Silo-HDF5 data for a given timestep.
     """
-    _check_h5py()
 
     base = os.path.join(case_dir, "silo_hdf5")
     if not os.path.isdir(base):

toolchain/mfc/viz/viz.py

@@ -70,6 +70,25 @@ def viz():  # pylint: disable=too-many-locals,too-many-statements,too-many-branc
 
     cons.print(f"[bold]Format:[/bold] {fmt}")
 
+    # Quick guide when no action is specified
+    if not ARG('list_steps') and not ARG('list_vars') and ARG('var') is None:
+        cons.print()
+        d = case_dir
+        cons.print("[bold]Quick start:[/bold]")
+        cons.print(f"  [green]./mfc.sh viz {d} --list-steps[/green]"
+                   "                   [dim]see available timesteps[/dim]")
+        cons.print(f"  [green]./mfc.sh viz {d} --list-vars --step 0[/green]"
+                   "            [dim]see available variables[/dim]")
+        cons.print(f"  [green]./mfc.sh viz {d} --var pres --step 0[/green]"
+                   "             [dim]render a PNG[/dim]")
+        cons.print(f"  [green]./mfc.sh viz {d} --var pres --step all --mp4[/green]"
+                   "     [dim]render an MP4[/dim]")
+        cons.print(f"  [green]./mfc.sh viz {d} --var pres --step 0 --slice-axis z[/green]"
+                   " [dim]3D midplane slice[/dim]")
+        cons.print()
+        cons.print("[dim]Run [bold]./mfc.sh viz --help[/bold] for all options.[/dim]")
+        return
+
     # Handle --list-steps
     if ARG('list_steps'):
         steps = discover_timesteps(case_dir, fmt)

toolchain/pyproject.toml

@@ -37,6 +37,11 @@ dependencies = [
     "seaborn",
     "matplotlib",
 
+    # Visualization
+    "h5py",
+    "imageio>=2.33",
+    "imageio-ffmpeg>=0.5.0",
+
     # Chemistry
     "cantera>=3.1.0",
     #"pyrometheus == 1.0.5",