update

Author: mmukta

render_frames.py

@@ -0,0 +1,117 @@
+#!/usr/bin/env python3
+"""
+Script to render LAMMPS dump files to PNG images using OVITO
+"""
+
+import sys
+import os
+from pathlib import Path
+from ovito.io import import_file
+from ovito.vis import Viewport, OSPRayRenderer
+
+
+def render_dump_to_images(dump_file, output_dir=None, width=1920, height=1080, frame_step=1):
+    """
+    Load a LAMMPS dump file and render frames to PNG images
+    
+    Parameters:
+    -----------
+    dump_file : str
+        Path to the dump file
+    output_dir : str, optional
+        Output directory for images. If None, creates 'frames' subdirectory
+    width : int
+        Image width in pixels
+    height : int
+        Image height in pixels
+    frame_step : int
+        Render every Nth frame (default: 1 = all frames)
+    """
+    
+    # Import the dump file
+    print(f"Loading dump file: {dump_file}")
+    pipeline = import_file(dump_file)
+    
+    # Add pipeline to scene so it will be rendered
+    pipeline.add_to_scene()
+    
+    # Generate output directory if not provided
+    if output_dir is None:
+        base_name = Path(dump_file).stem
+        output_dir = f"{base_name}_frames"
+    
+    # Create output directory
+    os.makedirs(output_dir, exist_ok=True)
+    
+    print(f"Output directory: {output_dir}")
+    print(f"Number of frames: {pipeline.source.num_frames}")
+    print(f"Rendering every {frame_step} frame(s)...")
+    
+    # Set up viewport for rendering - Left view (XZ plane)
+    vp = Viewport()
+    vp.type = Viewport.Type.Ortho  # Use orthographic projection
+    vp.camera_pos = (0, 100, 0)  # Position camera along Y-axis
+    vp.camera_dir = (0, -1, 0)   # Look towards the structure (negative Y)
+    vp.fov = 60.0
+    
+    # Zoom to fit the scene
+    vp.zoom_all()
+    
+    # Use OSPRay renderer (software-based, works without display)
+    renderer = OSPRayRenderer()
+    
+    # Render frames
+    frames_to_render = list(range(0, pipeline.source.num_frames, frame_step))
+    for i, frame_num in enumerate(frames_to_render):
+        output_file = os.path.join(output_dir, f"frame_{frame_num:05d}.png")
+        
+        try:
+            vp.render_image(
+                filename=output_file,
+                size=(width, height),
+                frame=frame_num,
+                renderer=renderer,
+                background=(1, 1, 1),  # White background
+                alpha=False
+            )
+            
+            if (i + 1) % 10 == 0 or i == len(frames_to_render) - 1:
+                print(f"  Rendered {i + 1}/{len(frames_to_render)} frames")
+                
+        except Exception as e:
+            print(f"  Error rendering frame {frame_num}: {e}")
+            continue
+    
+    print(f"\nDone! Images saved to: {output_dir}/")
+    return output_dir
+
+
+def main():
+    """Main function to handle command line arguments"""
+    
+    if len(sys.argv) < 2:
+        print("Usage: python render_frames.py <dump_file> [output_dir] [width] [height] [frame_step]")
+        print("\nExamples:")
+        print("  python render_frames.py bend-L10-s50-b3-l1.dump")
+        print("  python render_frames.py 10/bend-L10-s50-b3-l1.dump frames_output")
+        print("  python render_frames.py dump.dump frames_output 1280 720 5")
+        print("\nParameters:")
+        print("  frame_step: Render every Nth frame (e.g., 5 = every 5th frame)")
+        sys.exit(1)
+    
+    dump_file = sys.argv[1]
+    output_dir = sys.argv[2] if len(sys.argv) > 2 else None
+    width = int(sys.argv[3]) if len(sys.argv) > 3 else 1280
+    height = int(sys.argv[4]) if len(sys.argv) > 4 else 720
+    frame_step = int(sys.argv[5]) if len(sys.argv) > 5 else 1
+    
+    # Check if dump file exists
+    if not Path(dump_file).exists():
+        print(f"Error: Dump file not found: {dump_file}")
+        sys.exit(1)
+    
+    render_dump_to_images(dump_file, output_dir, width, height, frame_step)
+
+
+if __name__ == "__main__":
+    main()