Update default pi0 ckpt_path and documentation for the new weights

workflows/robotic_ultrasound/scripts/simulation/evaluation/README.md

@@ -67,6 +67,26 @@ If no prediction source arguments (`--method-name`, etc.) are provided via the c
 
 The script expects predicted trajectory files to be found at `data_root/file_pattern`.
 
+## Downloading Model Weights
+
+The four policy models discussed in the evaluation (Pi0-400, Pi0-800 w/ cosmos, GR00T-N1-400, and GR00T-N1-800 w/ cosmos) can be obtained using the `i4h_asset_helper` utility. This utility helps manage and download versioned assets.
+
+To integrate these models into your workflow, you would typically define an `Assets` class that inherits from `BaseI4HAssets`, specifying the asset identifiers. Below is an example demonstrating how these might be structured.
+
+```python
+from i4h_asset_helper import BaseI4HAssets
+
+class Assets(BaseI4HAssets):
+    Pi0_400 = "Policies/LiverScan/Pi0"
+    Pi0_800 = "Policies/LiverScan/Pi0_Cosmos"
+    GR00TN1_400 = "Policies/LiverScan/GR00TN1"
+    GR00TN1_800 = "Policies/LiverScan/GR00TN1_Cosmos"
+```
+
+You can then use these definitions in your scripts to get the local path to the downloaded model files, for example:
+`pi0_400_model = Assets.Pi0_400`
+`gr00t_800_model = Assets.GR00TN1_800`
+
 ## Understanding the Outputs & Experiment Results Comparison
 
 The `evaluate_trajectories.py` script generates several outputs to help you assess the performance of trajectory prediction methods. Below is a description of these outputs, along with an example showcasing a comparison between Pi0 and GR00T-N1 models.

workflows/robotic_ultrasound/scripts/simulation/examples/ultrasound_raytracing.py

@@ -232,13 +232,13 @@ def add_mesh(filename, material_name):
         default_curvilinear_probe_params = {
             "num_elements": 256,
             "sector_angle": 73.0,  # degrees
-            "radius": 45.0,         # mm
-            "frequency": 2.5,       # MHz
+            "radius": 45.0,  # mm
+            "frequency": 2.5,  # MHz
             "elevational_height": 7.0,  # mm
             "num_el_samples": 1,
-            "f_num": 1.0,          # unitless
-            "speed_of_sound": 1.54, # mm/us
-            "pulse_duration": 2.0   # cycles
+            "f_num": 1.0,  # unitless
+            "speed_of_sound": 1.54,  # mm/us
+            "pulse_duration": 2.0,  # cycles
         }
 
         default_sim_params = {
@@ -292,7 +292,7 @@ def add_mesh(filename, material_name):
             num_el_samples=probe_params["num_el_samples"],
             f_num=probe_params["f_num"],
             speed_of_sound=probe_params["speed_of_sound"],
-            pulse_duration=probe_params["pulse_duration"]
+            pulse_duration=probe_params["pulse_duration"],
         )
 
         # Create simulator

workflows/robotic_ultrasound/scripts/simulation/utils/assets.py

@@ -23,7 +23,7 @@ class Assets(BaseI4HAssets):
     panda = "Robots/Franka/Collected_panda_assembly/panda_assembly.usda"
     phantom = "Props/ABDPhantom/phantom.usda"
     table_with_cover = "Props/VentionTableWithBlackCover/table_with_cover.usd"
-    policy_ckpt = "Policies/LiverScan"
+    policy_ckpt = "Policies/LiverScan/Pi0"
     organs = "Props/ABDPhantom/Organs"