This time I bring a new method to mix fluids with using Graphs in RealFlow.
Thanks to the help of Alex Ribao from Next Limit I would like to share this graph to mix two fluids using the temperature channel of the fluids. This idea is not mine I took it from Thomas Schlick https://rftoolfactory.wordpress.com/2015/01/21/fluid-blending/, but instead of using py script we use Graphs that is faster in calculations in some cases.
This a pretty simple scene of two fluids, yo can set different properties, as viscosity, density, etc. Even using this method I think you could do it more complex and mix properties between fluids.
But firstly I would like to prevent you that exist some tricky things in this method that we have been aware. By default liquid emitters have not temperature channel so to create them we have to switch them to Gas and we should set the temperature to 0 for one and to 1 for the other and switch again to Liquid, so we had the channels created.
Once done this we only need to load the Graph to the stepPre slot in the Simulation Graph.
The graph is quite simple, the particles from both emitters are loaded and read positions and temperatures, then through creating a distance field the particles transfer the temperatures between them and these are updated. The mixed area can be controlled with the CellSize node, although you can add extra control in the rendering process too. For rendering, this time I used Arnold through RenderKit, now I am testing the workflow with Maxwell and will try in VRay too. This are the connections for Arnold.
Looking in my old stuff I found some comparative videos I would like to share, these are not really relevant but could help anybody to have a better understanding of this tool.
Sorry! In some videos attribute values are not showed.
Cover Scape Limit
Cover Outer Limit
Cover Inner Limit
This is my personal approach to the lava behaviour, although there are several types of lava I´ve choosed a very high viscous type. The most important in the lava simulation is combine both motion and shading. In this case I used Render Kit to read the implicit parameters in the particle bin files. I started doing some tests with a simple simulation of a draining drop I had simulated yet, the settings are viscosity to 60 and surface tension to 560.
The previous example has the vorticity computed to use it later. Although the simulation is pretty simple it gives you the opportunity to play with several parameters in the shading, velocity, pressure, vorticity, etc.. You can download the shader to explore it in depth, I have to say it could be improved.
The most complex was to get a good shading network that allow me to control the lava look without to change a lot of parameters, for this renders I used a combination of texture and vorticity data from particles bins.
These are several tests I did…
…and the one I choosed a little bigger.
The next step was to apply this settings to a lava flow type simulation. The simulation is not very impressive, but enough to demonstrate that is very important the way you simulate the fluid, comparing with the first example the look is different due to de simulation, but the shader is the same.
Next, both RealFlow simulation and render videos. I added a roughness map to the slide surface to break the shape in the fluid.