A directional statue destruction effect created using procedural fracturing in Houdini and vertex animation as well as cinematic lighting, to achieve breakage without physical simulations.
Model Processing, Fracturing and Data Storage
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The original statue was reduced to a half-body bust. UV mapping was adjusted, and the model was remeshed using VDB conversion to ensure watertight geometry and improve topology for fracturing.
- Non-uniform fracturing was performed based on proximity to an explosion point, with smaller, denser fragments near the center.
- A PyroSource node was used to scatter points within the explosion sphere. Points outside the statue were removed, and the remaining points guided the RBD Material Fracture process.
- Centroid coordinates and distances from the explosion center were stored in UV channels: UV1 — X and Y centroid coordinates; UV2 — Z centroid coordinate and distance to the explosion center.
- Data Unpacking: Centroid coordinates and distances were unpacked from the UV channels in UE, with corrections for coordinate differences between Houdini and Unreal.
- Displacement: Fragments were animated with two types of displacement:
- Axial Displacement: Movement along the explosion axis, scaled by destruction progress and shaped with noise and sine waves to simulate gravity.
- Radial Displacement: Outward scattering from the explosion axis, scaled by noise and destruction progress.
- Rotation: Fragments rotated around their centroids, with random rotation axes and speeds tied to destruction progress. Smaller fragments rotated faster for a dynamic effect.
- Destruction Progress: A scalar parameter controlled the sequence, determining each fragment's position and rotation based on its distance from the explosion center.
- Volumetric fog and lighting were carefully adjusted to added depth and atmosphere, with several cubes placed to block directional light and create the desired god ray shape. Two rect lights were positioned to subtly highlight the statue from specific angles.
- Color grading was adjusted in post-processing to fine-tune the overall tone and mood.
- Sequencer: Destruction progress was keyframed in Unreal’s Sequencer using a Material Parameter Collection to synchronize animation timing.
- Rendering: The final animation was rendered with the Movie Render Queue for high-quality output.