This is a shading experimentation on liquids.
I was amazed by bottles VFX in HalfLife Alyx, and I thought it was a good exercise to try to reproduce a similar effect.
No real simulation or anything baked here. The bottle's movement data (velocity, attenuation...) is computed and smoothed on CPU then send to GPU, where it drives three directionnal Gerstner waves and two normal maps. Rendering the liquid is done with raymarching in fragment shader (no other mesh is used, only the bottle). For the lighting I sample an hdri with the computed reflection and refraction vectors (no UE4 shader is used, everything is customly made in HLSL).