How can I increase the apparent detail in a volume at render time?

[kleer001]

I think I remember seeing a paper about it somewhere. It seems like it shouldn't be too crazy. Is it?

Has anyone here done it in production or hobby-time?

I'm trying to use the uprez solver, but it's finicky and keeps giving me unpredictable results.

 

OR, is there any way to smooth out those raster alias steps in borderline too-big voxels?

[Solitude]

There are a few things you can do:

 

*For just too-big voxels you can change the volume filter to different types to smooth it out, but sometimes that will actually kill detail as well. 

 

*Use ramps on the density field to modify the 'contrast' between low and high density, or peak up middle values a bit (pyro shader)

 

*Use dual rest fields and add 3d textures that move with the fluid (pyro shader) (multiply values or add value to current field)

    * You can also use the rest fields to also displace the volumes if you have a "N" field of some sort, which is typically the gradient from the density field  (pyro shader) (can be slow to render, but look cooler than multiplying)

 

*Gridless advection is probably the paper you are referring to. It's very slow from what I hear. Looks like it can add nice 'smooth' streaky detail, which is great for certain situations (cigarrette smoke or wispy cloudy stuff I think).

  *Thread here: http://forums.odforce.net/topic/16415-gridless-advection/

  *Good video here:

and here: 

 

*UpRes solver, would be my first go-to if I absolutely need to keep the same sim... but like you said it can be finicky if you're not used to it.

    *Instead of Upres, you might as well just sim at a higher resolution if you can't get a good result from it

Edited June 20, 2014 by Solitude