Density rendering of the Kelvin-Helmholtz instability (∆ρ = 2) at t = 2 (three left columns) and t = 4 (three right columns) for varying resolution (n_x = 64,128,256), N_smooth = 32,64,128, and method (GDSPH upper three rows and ISPH bottom three rows). The X and Y axis have a length of 1a. These simulations were all run with the optimized kernel for each O_Nsmooth GDSPH and OI,_Nsmooth for ISPH. We can see that ISPH manages to generate the same vortex structure, regardless of the number of neighbors if the resolution is high enough, while GDSPH struggles with lower number of neighbors even at the highest resolution.