Volumetric Long Expousures
Splatting
For this project, we explored a unique fusion of traditional photography and modern VFX: volumetric long exposure. Inspired by the motion trails and light painting effects found in long-exposure photography, we aimed to bring this aesthetic into a fully 3D space, creating fluid, sculptural forms that captured movement over time in a way that conventional photography could not.
The design process began with analyzing real-world long-exposure photography—examining light trails, motion blur, and persistence of vision. Our goal was to translate these principles into volumetric data, allowing us to generate a sculpted representation of movement rather than a simple 2D streak.
To achieve this, we needed a method that would allow us to "trap" motion into a volume over time. Traditional motion blur techniques in CGI only simulate persistence within a single frame, so we developed a custom pipeline that accumulated motion data across multiple frames, building up a true volumetric representation of movement.
Motion Capture & Particle Systems: We started by capturing movement data, whether from actors, simulated objects, or animated elements. This was then converted into particle trails, with each particle representing a point in time within the motion sequence.
Volumetric Accumulation: Using Houdini, we developed a system that allowed these motion trails to be accumulated into volumetric voxel data. This created dense, flowing forms rather than individual lines, giving the effect a sculptural quality.
Shading & Rendering: To enhance the final look, we experimented with emissive shaders, subsurface scattering, and transparency, mimicking the ethereal glow often seen in real long-exposure photography. The challenge was to maintain depth and texture so that the volumetric forms felt tangible and dynamic rather than flat.
Artistic Direction & Refinement: Because this technique inherently abstracts motion, we worked closely with the creative team to ensure the final results retained a sense of purpose and intention. The balance between realism and stylization was key—too much detail, and it lost its painterly quality; too little, and it lacked the visual richness we wanted to achieve.
