Fluids Smoke

[alexx]

hmm… do the clouds have to move?

does the camera move?

if not (or even if so) you could think about a rendering that holds all informations at once…
meaning: you have your lightnings all switched on in the rendering, but all with different pure colors (pure red, green, blue)…

you can then get rid of the color information in a post programm and then later use the color infrmation only to “switch” the lightnings on and off in the post app as well…
like that you only have to render one single pass.

no idea if that can work for you.

cheers

alexx

[Julius]

The shader is called “fluidShape”. One thing to be aware of is that the fluidShape node is both a shader and a shape. When you create it off of the fluids menu it gets assigned to its self and thus appears as a rendered box. When you create it off of the shader menu it is assigned to whatever is selected. The box shown in the UI will then not render as it is not assigned any shader.
Duncan

Sorry Duncan, I’ve done this except the box still appears. How come in alex’s scene file i cannot see his fluidshape box?

[skylight]

Sorry Duncan, I’ve done this except the box still appears. How come in alex’s scene file i cannot see his fluidshape box?

Me，too～
How to make a fluidshape i s a real shader，not a container ??:shrug:
I saw the shape Dispay–>Boundary Draw is Bottom (default)

I create the shape ，too.
Every function set similar like the Alex’s shape setup.
But i’m failed…still a fluid , not a shader…

Sorry , I’m brainless man，and my English was so broken…:sad:
Thanks Alex’s file，very great:applause::bounce:
Hope someone can help me a few, thanks~

[Duncan]

The fluid container appears in the UI, but it should not show up in the renders(if you have created it by assigning a fluid shader). Render volumes need a container( the geometry ) and a shader. In the case of fluids we normally simply assign a fluid shader to its own container… the same node is both shader and geometry. It would be confusing, but one could assign one fluid to another’s container, in which case the second fluid would show the first when rendered.
If desired one could create a number of volume sphere, cube, cylinder and cone nodes and assign a fluid shader to them. The fluid will be instanced to the location of each container at render time.

 Duncan

[Duncan]

If you don’t want the fluid node to appear in the UI you can simply make it invisible.
If it is assigned to other surfaces or volumes they will still show the fluid at render time.
Another way to turn off display in the UI is to set the shaded and wireframe draw display methods on the fluid shape to OFF.

Duncan

[Julius]

If you don’t want the fluid node to appear in the UI you can simply make it invisible.
If it is assigned to other surfaces or volumes they will still show the fluid at render time.
Another way to turn off display in the UI is to set the shaded and wireframe draw display methods on the fluid shape to OFF.

 Duncan

Thanks Duncan, you’ve been a great help and thanks to alexx for sharing his file.

[skylight]

Oh…it’s just very simply option---->visable off!!
sorry:rolleyes:

[luispages]

Hello everyone and thanks to Duncan for sharing this info… I have a question about this technique, I have an expression for radiusPP to increase the size of the particle over time… the particles render ok at birth but as they increase in size they start to look really bad, is the size of the container related with the look of the particle?

Also any tips on how to connect opacityPP to the fluid shader in order to have the particles fade as they die?

Thanks a lot

[ThE_MaStEr_Of_DyNaMi]

hi, i wanna know how to create a nice looking explosion on maya using either using particles or
fluids.

help needed

[Duncan]

The fluid container is essentially transformed to the local space of the particle, and thus is scaled with the particle scale. I’m not sure why it gets bad looking for you when larger.

To modify the opacity per particle, create a particleSamplerInfo and connect the opacity per particle from the particleSamplerInfo to the attribute you desire to modulate on the fluid.
You could drive the transparency color, or perhaps the opacityInputBias. If desired you can also connect to the individual ramp indices on the graphs, driving either their value or their position from the particleSamplerInfo.

Duncan

[luispages]

Hello Duncan and thanks for your response… I think I found the reason of the problem for the bigger particles and it seems to be that the space between particles is much bigger at the end of the trail, now would you recomend to connect opacityPP to the fluid container using an expression or in the Hypershade?, and which atribute will make them fade out as they get older?

Thanks a lot

[ThE_MaStEr_Of_DyNaMi]

Like This?

Ive found that the key to getting good thick billowing smoke with maya fluids is to have a simulation with a very dense mass of fluid. For that image i used a dynamic grid for all 4 of the contents methods. The fuid emitter is set to 8 for density and 1 for heat and fuel.
Once you get your thick mass of fluid flowing the way you want, then just use a texture to get the billowing look. I like to use ‘spacetime’, but if you can an afford the extra rendertime, use ‘billow.’ For the coloring, I used a Y gradient that starts with black on the bottom and goes up to a light charcoal color. The incandesence is set to ‘temperature’ with a dark/blueish black for the main base and sharp falloff to a light charcoal. This just keeps the center dark, and makes the very edges of the fluid a bit lighter.

i liked your fluid much but i would like more details about this kind of smoke including velocity, damping and some emitter attributes.

[Duncan]

now would you recomend to connect opacityPP to the fluid container using an expression or in the Hypershade?, and which atribute will make them fade out as they get older?

The expression could modify the opacityPP, for example saying something like
opacityPP = opacityPP * 0.9;

Then one would create shading network connections from the particleSamplerInfo opacityPP to a fluid attribute, like opacityInputBias. One does not connect to the fluid from inside the particle expression… the particle expression is evaluated once per particle per frame. The particleSamplerInfo input value, by constrast, gets evaluated for every shading sample(per pixel). The way the Maya Shading Engine works with shading nodes is that there are certain attributes names, like normalCamera, that the engine recognizes. If these exist on a node then it stuffs the value of these attributes with the relevent values for the pixel being rendered. All the samplerInfo and particleSamplerInfo nodes are is a collection of attributes… they compute nothing. One could stick the same named and typed attribute on a different node and it would work the same(you will notice that normalCamera, for example, exists on all nodes that use this attribute).

Note that you do not need to have a particle expression to fade the particles with age… you could directly connect the sampler’s normalized age attribute(instead of opacityPP) to a valueRemap node then connect the outColor of this to the fluid transparency. You can then edit the color ramp on the valueRemap node to edit the transparency of the particle across its age.

 Duncan

[luispages]

Thanks a lot Duncan I’m gonnn agive a shot and I’ll let you know the results.

[ThE_MaStEr_Of_DyNaMi]

Like This?

Ive found that the key to getting good thick billowing smoke with maya fluids is to have a simulation with a very dense mass of fluid. For that image i used a dynamic grid for all 4 of the contents methods. The fuid emitter is set to 8 for density and 1 for heat and fuel.
Once you get your thick mass of fluid flowing the way you want, then just use a texture to get the billowing look. I like to use ‘spacetime’, but if you can an afford the extra rendertime, use ‘billow.’ For the coloring, I used a Y gradient that starts with black on the bottom and goes up to a light charcoal color. The incandesence is set to ‘temperature’ with a dark/blueish black for the main base and sharp falloff to a light charcoal. This just keeps the center dark, and makes the very edges of the fluid a bit lighter.

i liked your fluid smoke much and i would be grateful if u told me how to create such smoke from A to Z

help needed !!!

[luispages]

Ok well this are my results…
http://solidanimations.com/tuggerdust.htm

[alexx]

brutal

i think there is a jump in the fractal ever 4 frames or so. can that be?
without that jump it would be really cool.

can you render it once (about 10-20 frames only) with a static camera? then you can judge easier where the problem could be.

cheers

alexx

[luispages]

Helo Alexx, is that comment about my post or another one?

[luispages]

Note that you do not need to have a particle expression to fade the particles with age… you could directly connect the sampler’s normalized age attribute(instead of opacityPP) to a valueRemap node then connect the outColor of this to the fluid transparency. You can then edit the color ramp on the valueRemap node to edit the transparency of the particle across its age.

 Duncan

Duncan I’ve been trying this method but I’m not getting any results, ageNOrmalized gives me one output that I dotn see where to plug into the remapColor, any advice?? I’m trying to fade this particles as they die, I’m also trying to figure out how to randomize the look of the particles because using the sampler info node plugged to texture time gives me a lot of noise, I’m working in a tornado and so far it’s being impossible to get a soft random look…

On the lil video I posted here with the jeep and the dust behind it is a bit hard to tell but I get the same noisy behavior that alexx pointed out…

What do you guys think…

[future14]

i did tried the method suggested by Duncan, i pluged the ageNormalized to the input value of the remapValue node, then connect the outColor of the remapValue to fluid transparency, it works only for maya software render, but not for the mentalray render.