Phoenix Lava, How??

[Raven]

Looking into phoenix for a lava solution, no problem on the liquid simulation side.
But how would you map the lava so that it follows the liquids movement?

Quote from Phoenix features
"Dragging of UVW/mapping channels coordinates
The user is able to drag UVW coordinates with the fluid and use them to map other textures. The UVW channel can be also exported as a map."

is this automatic when you select UVW on the phoenix source, seamed to just stretch the map for me.
what am I missing?

I would like dark crust (displaced) patches to flow on the surface.

Also if I set higher temperature on the fluid, does this cool over time, and if so
could that info be used to map hot and cold spots in the material (mix map with hot and cold lava)

Quote from Phoenix features
" the texture export allows the creation of many special effects, for example lava-looking surface achieved with displaced transparency channel and non displaced emissive channel etc"
How does this work? have you got an example of this in practice.

Thanks very much

[Ivaylo Katev]

yes, the UVW coordinates are the best solution for lava sims.
you don't need to put any uvw coordinates in the source, just enable the uvw export in the output channel. the uvw content will be initialized with the local coordinates and when the movement drags the channel the result will become thready like a lava.
for the mapping you just have to select explicit channel in the displacement map you use, this is enough. for example, select a noise texture for the displacement, and select explicit channel in the texture settings.
the lava appearance, i.e. to make the slits to look hotter than the surface is more complicated. the help fragment you cited is targeted to the smoke rendering, however the concept is the same, just the "transparency channel" here is replaced with the effects channel, that determines the liquid surface. so, with simple displacement based on a simple noise using explicit mapping you will have a lava looking surface, now only the proper coloring should be added. the concept here is to use the liquid itself but *before* the displacement as a color determining factor. this way, the areas displaced "up" will have one color because are in the air, and the areas displaced "down" will have different color, because are in the liquid.
of course for the texture presenting the color we need a second simulator instance to avoid the circular reference. may be i should create a small example, i think it would attract some interest.

[Raven]

Thanks for the reply.
I will play around with that.
An small example would be great.

[Ivaylo Katev]

bad news - there is a bug when is used displacement with a map using uvw. i'm sure i used this one year ago, so the problem is perhaps only in 1.2....
anyway, this does not make the task impossible, it's just harder.

[Ivaylo Katev]

here is the result until now, however the hardest part is not the appearance, but the movement of the displacement texture together with the liquid. excluding the uvw based displacement, the only way that i see is to use the particle texture, it is made with this in mind. for smoke this technique is very slow, but for geometry can be useful i think.

[jacksc02]

it just needs some heat haze and smoke and its done

[Raven]

Thanks Ivayalo but I get the "Your user account may not have sufficient privileges to access this page."
so I cant see the image.

[Ivaylo Katev]

ah yes, the forum access.

[Raven]

Looks great, thanks.

[Raven]

would it be possible to get the max file, mine ends up looking like this.

[Ivaylo Katev]

of course

[Raven]

thanks very much, unfortunately not the effect we are looking for.
I need to know if the uvs can flow with the liquid to achive this fast flowing lava effect.
http://www.youtube.com/watch?v=ZewWypjo0SY
or this
http://www.youtube.com/watch?v=yS9ii0wuqBQ

[Ivaylo Katev]

the first one is 100% possible with uvw dragging, no displacement, only mapping of the texture used in the material. a made a fast test, and here is the result.

the second one i think is possible dragging particles and directly associating some geometry to them.

[Raven]

fantastic, exactly what i think i need, how do I apply uv dragging?

[Ivaylo Katev]

here is the scene.
i made a change in the simulation (SPF lower limit), to avoid the waves over the lava surface. with displacement these waves were almost invisible, but with texture are quite visible. i think the movement should be good enough, however for long distances the uvw channel tends to become uniform (due to the mixing) and the lava details will disappear.
the important detail here is that the uvw is produced from an animated map applied to the source. this map has significant influence over the final appearance