VFX Artist Raúl Fernández Guardia showcased his technique that addresses common challenges with applying blur to translucent surfaces, while also providing seamless integration with Niagara and Blueprints.
As he shared, here NDCs act as new data containers that Niagara and Blueprints can both read and write to. These NDCs are used to send blur information, such as position, radius, and intensity, from any Niagara system or Blueprint. A Manager System then converts the world positions into grid coordinates and encodes the remaining attributes like radius and intensity to generate motion vector data. Because the Grid Space aligns perfectly with Screen Space, this data is stored in a Render Target texture. Finally, a post-process material samples this texture, using the encoded direction and intensity values to apply the final effect.
Raúl reported that this method is very fast, using Niagara Grid 2D as a GPU compute shader to efficiently emulate texture space. Because the blur is applied as a post-process, it avoids overdraw issues. In the artist’s tests at 2K resolution with multiple instances on an RTX 3080Ti, the blur cost remained around 0.05 to 0.08 milliseconds per frame, which is under 1% of the frame budget at 120 FPS.
For more details, see here. The Grid2D Motion Vector Blur will be included in Raúl’s Advanced Motion Blur Shaders pack for Unreal Engine 5. Another highlight in the pack is the Per-Object Blur, which uses stencil masking and depth-aware techniques to selectively blur individual objects, maintaining visual quality while avoiding typical post-process artifacts.
