Wetmap resolution

[Neilg]

I am having some issues with the wetmap detail - the liquid resolution looks fine as it is motion blurred, but there are nowhere near enough wetmap particles to create a consistent mask. It's very speckled and increasing the size of it so they all meet up makes it too big.

I was reading around the forums and the advice given in this case was to increase the entire simulation resolution - is that the only option, there's no way to check on to generate wetmap particles at a much higher resolution than the simulation grid? Increasing the simulation resolution to push the wetmap particles closer together looks like it would need an increase from 15m cells to about 150m and isn't going to be possible on this.

[Ivaylo Katev]

Without an image it's hard to give good advice, but shooting in the dark i would say that not the particles density is the problem, but the setup of the particle texture, perhaps small radius or something like that.

[Svetlin.Nikolov]

Indeed, the wetmap resolution is currently controlled by the resolution of the simulator. Let me see if it would be possible to extend this to a custom resolution. However, it would be important to know the use case, so if you can share a screenshot, it would be very helpful!

[Neilg]

Without an image it's hard to give good advice, but shooting in the dark i would say that not the particles density is the problem, but the setup of the particle texture, perhaps small radius or something like that.

The issue is that with a bigger radius so that all the particles touch/blend, the wetmap extends so far beyond the simulation fluids that it doesnt look right. we're only talking 15mm - but it's a splash of blood onto fabric which then runs down it. It's fast and motion blurred, so i'm getting away with a 'low res'-ish sim which is still 80m cells.
it's very obvious when the wetmap is much wider than the fluid sim, and when adjusted to sit tighter to the sim it separates into particles.

I will render something this week to show it. I remember having this same issue when i was testing the wave force with a beach scene - can get away with much lower res simulations when everything is in motion but the wetmap particles - either them being speckled or huge, exposes it.

A 'particle detail' multiplier seems like it would be useful - 2x, or 3x etc. Would that slow the simulation down much? I'm assuming as it's only checking for intersections that this would be significantly faster than decreasing the cell size?

[Svetlin.Nikolov]

Ahh, got it, yes. In this case sounds like only higher wetmap resolution would help. It might not slow the simulation down that much if we use a dense grid for the wetmap at a higher resolution, but this would raise the ram usage...

[japetus]

I second this!