Vertex Animation Textures
for stylized effects
Unreal Engine 4
From Houdini Dynamic Operators (DOPs) to Unreal Engine shader magic, here is an example of the "offline sim to real-time effect" workflow made possible by the latest features of Houdini and the amazing work of Luiz Kruel from SideFX.
Based on a dynamic sim made with the Pyro solver in Houdini, the voxel-based volumetric simulation gets transformed to a polygon mesh and then exported as a set of separated triangles, along with a Position map baked on a 16-bit texture that will be read back in the vertex shader in UE4 to replay the entire sim in real-time.
Using this animated mesh on a PopcornFX particle system gives the possibility to spawn different configurations and create curves and attributes to control some of the material parameters over the life of the mesh particle. Here, just some random rotations, a color evolution and some size tweaking are the only few things needed to achieve this beautiful cartoony explosion effect!