Dangling changes and address boundary errors

1 files changed, 75 insertions, 0 deletions

diff --git a/vtk_to_png.py b/vtk_to_png.py
new file mode 100644
index 0000000..9c3f4f3
--- /dev/null
+++ b/vtk_to_png.py
@@ -0,0 +1,75 @@
+import vtk
+import glob
+import os
+
+vtk_files = sorted(glob.glob("*.vtk"))
+output_dir = "frames"
+os.makedirs(output_dir, exist_ok=True)
+
+renderer = vtk.vtkRenderer()
+render_window = vtk.vtkRenderWindow()
+render_window.SetOffScreenRendering(1)
+render_window.SetSize(1024, 512)
+render_window.AddRenderer(renderer)
+
+renderer.SetBackground(1, 1, 1)
+
+camera_initialized = False
+
+for i, vtk_file in enumerate(vtk_files):
+    reader = vtk.vtkStructuredPointsReader()
+    reader.SetFileName(vtk_file)
+    reader.Update()
+
+    image = reader.GetOutput()
+
+    mag = vtk.vtkImageMagnitude();
+    mag.SetInputData(image);
+    mag.Update();
+    image = mag.GetOutput();
+    scalar_name = "Velocity magnitude";
+
+    scalars = image.GetPointData().GetScalars()
+    if scalars is None:
+        raise RuntimeError("No scalar data found")
+
+    vmin, vmax = scalars.GetRange()
+
+    # Image slice mapper (2D!)
+    slice_mapper = vtk.vtkImageSliceMapper()
+    slice_mapper.SetInputData(image)
+
+    # Pick the only slice (or middle if dimension >1)
+    extent = image.GetExtent()
+    slice_mapper.SetSliceNumber(extent[4])  # Z slice
+
+    slice_actor = vtk.vtkImageSlice()
+    slice_actor.SetMapper(slice_mapper)
+
+    # Grayscale mapping
+    prop = slice_actor.GetProperty()
+    prop.SetColorWindow(vmax - vmin)
+    prop.SetColorLevel(0.5 * (vmax + vmin))
+
+    renderer.RemoveAllViewProps()
+    renderer.AddViewProp(slice_actor)
+
+    if not camera_initialized:
+        renderer.ResetCamera()
+        camera_initialized = True
+
+    render_window.Render()
+
+    # Capture to PNG
+    w2i = vtk.vtkWindowToImageFilter()
+    w2i.SetInput(render_window)
+    w2i.ReadFrontBufferOff()
+    w2i.Update()
+
+    writer = vtk.vtkPNGWriter()
+    writer.SetFileName(f"{output_dir}/frame_{i:04d}.png")
+    writer.SetInputConnection(w2i.GetOutputPort())
+    writer.Write()
+
+    print(f"Saved frame {i} range=({vmin},{vmax})")
+