Other settings: SPF set to 2 for a more rounded thick liquid, it is okay to set SPF to 1 for a faster simulation. The Scene Scale is set to 8 for the same reason: the liquid appears thicker with a higher Scene Scale.

When the Interpolation is set to 0.1, as you can see, the TexUVW is less stretched. However, there is no realistic folding pattern that is usually seen in the "pahoehoe" lava. This setting is less expensive for computing, since you can run a rather low grid resolution and still get usable results.

When the Interpolation is set to 0.001, you can see patterns in the TexUVW, suitable for the "pahoehoe" type of lava. We still give the Interpolation a teeny tiny value instead of zero for balanced results. Notice we also up-res grid resolution in this example.

On top of the Phoenix FD liquid simulator we add VRayDisplacementMod. This modifier can turn the smooth mesh into a detailed one and make the pahoehoe lava mesh much more convincing.

Downable scene. Click here to download the final scene. Note that the texture maps and HDRI maps are not included in the package. You can download the texture maps from textures.com, and the HDRI maps from HDRI Heaven.

Fire simulation without & with turbulence

This is our source settings. Set the Emit Mode to Source Force and Smoke to 1.0. Enable the Fuel option with value of 1. Outgoing Velocity is set to 6.0m. Temperature is set to 2200.Next, let's take a look at the Volumetric shading. If we render with the default volumetric shading, as you can see, the details in the highlights are completely over-exposed and the smoke seems too thick.
Now let's take a closer look to the right half of the curve, that is below zero. This segment contributes greatly to the detail of the fire (indicated by white arrows).
However, sometimes we don't need the details described above, we just want the image overexposed on purpose. For example, in this night scene of a burning car. We move this control point of the curve upward (it was below zero), and at the same time, we increase the Fire Multiplier to 20.0 to produce a convincing fire shading at night time.
Here is the same scene during daytime. Notice the point at the curve below zero. The Fire Multiplier is set to a lower value compared to the night time scene. The curve and the gradient are slightly different from the ground fire settings previously mentioned, so further tweak of the settings is possible depending on different scenarios.
The downside of using Vertex Paint as a mask for Fire/Smoke source: the fire is emitted from the same spot. Here we introduce another technique: using a procedural texture as a mask for the source. The Cellular texture will do the work  and we can animate its Z offset, so we get an animated mask. 
As shown in  the video above, the animated mask makes the fire emit from various places, producing more convincing fire in motion.

See the screenshot, the color of V_dust_A and V_dust_B are set to light gray. RGB values are (203, 177, 159) and (252, 249, 247) respectively.

When light from the red hot explosion pierces the white smoke, it is very hard to avoid washout with the default settings (shown above). Even if we adjust the exposure in the VFB we still wouldn’t get  balanced exposure in every area of an image.

To overcome this problem, intuitively the first thing we do is to lower the Fire Multiplier in the Volumetric Render Settings of the Simulator. It does alleviate the problem as the parameter is the general multiplier for the fire color's intensity.

Alternatively, while keeping the Fire Multiplier to 1, we can lower down both the Light Power on Self and Light Power on Scene to 0.1. We get similar results.

- Light Power On Self controls the light intensity of the simulator's smoke.
- Light Power On Scene controls the light intensity over all scene objects except for the Phoenix FD Simulator itself.

But if you look more closely: the second option (adjusting the Light Power) gives you more details in the shading. So, we favor lowering the Light Power over the Fire Multiplier.

While keeping both Light Power on Self and Light Power on Scene to 0.1, what else can we do to increase details of our smoke shading? The answer is by adjusting the Physically Based option.This is a realistic model that multiplies the fire intensity by the Black Body Radiation model, which gives strong brightness to the hot parts of the fire. It transitions between an artistic look of the fire,when set to 0 and a realistic physically-based Intensity, when set to 1. In this case, we gave it a value of 0.2.
To further improve the appearance of our smoke, we can apply LUT to our final image. In the V-Ray Frame Buffer you can remap the image colors based on an IRIDAS .cube LUT (Look-Up Table) file. It transforms color input values to output values based on the specific LUT file.

Many LUTs emulate the film process. Film emulation gives you mid-tune control in an image. In this case, I use a LUT file called - 8650 Log from IWLTBAP. You don't have to use this specific LUT file, try any other LUT that works for you. Alternatively, you can achieve similar results by adjusting Levels & Curve in V-Ray Frame Buffer. You might need to sharpen your skill but you will get there.

Be sure to tick the "Save in image" if you want your rendering baked with the LUT. You can also tune down the LUT effect by reducing the weight in the VFB.
As you can see, after applying the LUT color correction, we see more middle tune and more details in the smoke shading.

Summarize
Here are what we do to improve the smoke shading:
- Lower the value of "Light Power on Self and Light Power on Scene"
- Lower the value of Physically Base
- Apply a LUT file to the final image

Final animation

By Hammer Chen, Gergana Lilkova

This is a kind of request tutorial. Many people have been asking me how I created a burning car in my previous "Burning Car RnD" video. It was done with fuel-based burning. The fuel starts to burn when the temperature reaches its ignition temperature. Fuel-based fire gives you a realistic burning effect; however, the fuel itself is a fluid, meaning the fuel will flow all over the surface. The overflow of fuels is harder to control and might cause undesired results.

In this tips & tricks article, I am going to show you an alternative method for creating a growing fire, based on an animated mask. The mask is generated with VRayDistanceTex from an animated box. Since we have full control over how far and how fast the mask expands, the fire is more directable than fuel-based. This method is more practical for production. That's why I prefer this technique.

Though I am using fire trails as an example, the same concept can be applied to many other burning effects - like a burning watchtower, a burning paper with the flame growing on a path of a letter, etc.
Overall setup. The fire is emitted from the plane on the ground. To control where the fluid is to be emitted, we place an animated box on top of the plane. The box is then added to the VRayDistanceTex object list. The VRayDistanceTex is a V-Ray specific procedural texture that returns a different color based on a point's distance to an object(s) specified in a selection list. So this procedural texture can be used in the mask slot of PHXSource. This way, we can direct the growth of fire simply by keyframing the box.

The box (22 X 38 X 568 cm) is animated in its height, with Noise Modifier on top, so the box can be used for the expanding of the fire as if it burns from one side of the plane to the other side. It is not necessary to be a box; it can be any geometry. We use box, in this case,  because we're going to create fire trails, and a box seems to be a natural decision for me.

Be sure to put the Box in the Exclude List in the Scene Interaction rollout of your Simulator. Otherwise, the geometry will disrupt your fluid simulation.

Fire / Smoke Source (PHXScource). For the fluid source, pick up the Plane in the scene. Put a VRayCompTex in the Mask slot. Set the Mask type to Texmap.

In the VRayCompTex, put a VRayDistanceTex in the Source A, and add Box001 in its Object list. This will generate a black-and-white mask for the PHXSource. To further make the mask more organic, we composite it with Source B - a procedural noise. In the end, you will have a growing mask as the image shown on left-bottom.

As for fluid simulation, beginners may find it is not easy to get the appearance of the fire they're after. Above is an image simulated with default dynamics and rendering settings. It is not bad but also it is not the type of fire we want in this case. There are several things you can do when creating small scale fire:

1. Use an appropriate conservation method in the Dynamics. The first thing to do is to change the conservation type. The default settings are Direct Symmetric + Multi-Pass, but they do not work for small scale fire. So we shift the conservation method to Direct Smooth and Backtrace for the Material Transfer. We also increase Steps Per Frame to 3, so we have a less noisy and smoother fire.

2. Gradient and Curve. Second, the curve in the Volumetric Options also plays an important role. Although the two images above look totally different, they are actually from the same simulation. The only difference is the curve and gradient in the Volumetric Settings. The default curve (left) creates an overexposure in the rendering, losing most of the details in the core of the fire; while the curve on the right shows details in the whole image. Notice the control point on the curve affecting the core strength of the fire and the corresponding color gradient at that position. With this curve and a custom-made gradient, we can have a flame without an over-exposure at its core (the highest temperature), as well as a realistic orange-yellow-blue color transitions.

3. Fire Opacity Modulation. The third thing is opacity modulation. This step might look trivial at first glance, but it affects the final look of your fire a lot. By default, the root of the fire appears too solid, and you can alleviate this problem by putting a VRayDsiatnceTex in the Modulate slot.
In the Objects list for the VRayDistanceTex, we add Plane001. This produces a mask modulating fire opacity at its root, and you get a more realistic fire by doing so. If the fire is set on a car hood, then you should put the hood bonnet geometry in the object list instead of a Plane. You get the idea.

4. PHXTurbulence. If you like your fire more energetic, you can add a turbulence force in the scene. With the right amount of Strength and appropriate size, the force will push the fire around, giving it an extra level of realism. Of course, if you like your fire more gentle, you can skip this step.Notice that I have also put a Plain Force act as a wind blowing the fire, but it is optional.

Final Results:


Another example with an extra bitmap (logo) composited in the mask for PHXSource:


Download the fire trails scene
The scene file for fire trails is rather small, and the setup is compact. As this article is not written in a step-by-step fashion, to make your life easier, you can click here to download the file and explore the scene yourself. Volumetric Setting file (*.tpr) file is also included. Happy sim and enjoy!

By Hammer Chen, Kristin Ivanova

In this article, I show how to create a fruit explosion with Phoenix FD for 3ds Max. The fruit explosion consists of two fruits colliding at a high speed, then they smash and their juices splash out.

For the purpose of illustrating this article, we’ve shaded the fruits to get a tomato-ye look. However, the shape and shaders of the two geometries can be customized to your liking to get whatever kind of fruit you want to smash We don’t focus on the shading information of the fruits here..

The most challenging part of this animation is the fruit mesh smashing. Instead of softbody or cloth simulation, I use 3ds Max's Morpher Modifier and keyframe the splitting fruit meshes. I avoid using any softbody/cloth simulation in this tutorial, because it is difficult to control the results. By keyframing the animation, you have full control and are able to add layers of detail.

Since the mesh motion purely relies on keyframe animation, it is crucial to find the right reference footage to align with. You could search for keywords like "high speed fruit" or "fruit explosion." Or you can go through any stock footage sites. Once you find a good footage, load it in 3ds Max. This way, you can align your keyframe animation to the footage in the viewport accurately.

1. Fruit geometry deformation
Based on observation from reference videos, I concluded that one basic fruit mesh and four different deformed meshes would be enough to recreate the fruit splitting effect. Start from modeling the basic shape. The fruit is modified from a simple sphere and the mesh is split as shown in the image above. All other four deformed meshes are derived from this basic mesh. This is to make sure all five geometries have the same topology and can be used as morph targets later.


We duplicate the basic mesh into four other meshes.. By moving the vertices or adding modifiers on top, we create four different deformed fruit meshes: split, bump_shape, dent, and FFD_deformed. These four geometries represent the various stages of changing the shape of the fruit during the collision. Add a Morpher modifier to the basic mesh and load up the four geometries as morph targets.

The above image shows the curves of four morph targets in the Curve Editor. At frame 15, the fruits collide. By mixing the various target shapes, we mimic the smashing effect when the two fruits collide, deform and rupture.

Beside the Morpher modifier, we add a Ripple modifier on top to get subtle oscillations when the fruits collide. Then, we keyframe the Ripple to emulate the effect.To randomize the motion and shape, we add an FFD3X3X3 modifier and set the keyframe to its Control Points. Then, we add a Shell modifier which enables the liquid to collide with the fruit meshes.
Once the single fruit is ready, we duplicate and rotate it, and then slightly shuffle the parameters in the Modifier stacks, so that the two don't look the same.

When the two fruits collide, we have to note that there must be one fruit that pushes the other. In this case, we assume that the fruit on the left side is stronger. We create a Dummy helper in the scene. Both fruits are linked to dummy. When they collide, set the key of the dummy so that the two appear moving together.
Final keyframed animation


2. Fluid Simulation 
Fluid simulation results


Final results


Download the Scene files
As a user, I know it's always handy to have the scene when following a tutorial. Here we provide you with the final scene to start with. Please note that the HDR image is not included among the assets in the zip file, so you may find differences with the final images. Feel free to insert your own  HDRI  into the V-Ray Dome light. Click HERE to download. Enjoy!