Versions Compared

Old Version 1

changes.mady.by.user Gosho Genchev

Saved on

compared with

New Version Current

changes.mady.by.user Slavina Nikolova

Saved on

Key

  • This line was added.
  • This line was removed.
  • Formatting was changed.

This page provides a step-by-step guide for creating a gasoline explosion simulation using Chaos Phoenix for 3ds Max.

Overview

...

UI Text Box
typeinfo

This is an Entry Level tutorial which requires no previous knowledge of Phoenix. A basic understanding of 3ds Max would be helpful but is not a prerequisite for being able to follow along.

Section
Column
width40%

This tutorial is created using Phoenix 4.30 Official Release and V-Ray 5, Hotfix 2 Official Release for 3ds Max 2018. You can download official Phoenix and V-Ray from https://download.chaos.com. If you notice a major difference between the results shown here and the behavior of your setup, please reach us using the Support Form.

The instructions on this page guide you through the process of setting up a gasoline explosion simulation in Phoenix for 3ds Max. By the end of the tutorial, you will be able to create your own explosion simulations, understand how the simulation interacts with other objects and will know the basics of editing some of the main settings of the Phoenix Fire/Smoke Simulator.

This tutorial is a companion to go along with the QuickStart video posted on our YouTube channel.

The Download button below provides you with an archive containing the start and end scenes.

 

UI Button
sizelarge
icondownload
titleDownload Project Files
urlhttps://drive.google.com/uc?export=download&id=1c0OX-_mUHIQvr36s49Dscx2QE97494-N
 

Column
width60%
HTML
<iframe width="720" height="480" src="https://www.youtube.com/embed/YUcNZ-jT_ek" frameborder="0" allow="autoplay; encrypted-media" allowfullscreen></iframe>
UI Text Box
typeinfo
  • The video is created using Phoenix 3.0, but the text version of the tutorial is updated and uses Phoenix 4.30 Official. In any case of doubt you may refer to the text.
  • Another way to create a Gasoline Explosion is to use the newer and improved version of the Gasoline Explosion Toolbar Quick Setup preset which is included in the Nightly Builds since 16 Sep 2020.

 

System Units Setup

...

Section
Column
width50%

Scale is crucial for the behavior of any simulation. The real-world size of the Simulator in units is important for the simulation dynamics. Large-scale simulations appear to move more slowly, while mid-to-small scale simulations have lots of vigorous movement. When you create your Simulator, you must check the Grid rollout where the real-world extents of the Simulator are shown. If the size of the Simulator in the scene cannot be changed, you can cheat the solver into working as if the scale is larger or smaller by changing the Scene Scale option in the Grid rollout.

The Phoenix solver is not affected by how you choose to view the Display Unit Scale - it is just a matter of convenience.

 

Go to Customize → Units Setup and set Display Unit Scale to Metric Meters.

Also, set the System Units such that 1 Unit equals 1 Meter.

Column
width50%

Image Added

 

Scene Setup

...

In the following steps we will show how to create a gasoline explosion simulation with the Phoenix Gasoline Explosion Preset.

After that we will explain how to set the simulation manually step-by-step for greater flexibility and control.

 

Gasoline Explosion Preset

...

Section
Column
width40%

We will begin by using a quick gasoline explosion preset.

 

Create a Sphere with a Radius of 24.0 meters. This sphere will be the source of the explosion.

Column
width60%

Image Added

 

...

 

Section
Column
width40%

With the sphere selected, click on the Gasoline Explosion Preset button from the Phoenix Toolbar.

Column
width60%

Image Added

 

...

 

Section
Column
width40%

Now press the Start Simulation button in the Toolbar.

Column
width60%

Image Added

 

...

 

Section
Column
width40%

Let the simulation run for a few seconds and you will have a chance to see the results in the viewport, click the Stop button to end the simulation process.

Column
width60%

Image Added

 

...

 

Section
Column
width40%

Here is a GPU Preview of the simulation.

Column
width60%

Image Added

 

...

 

Section
Column
width40%

To enable the GPU Preview as seen in the image above, select the Phoenix Simulator → Preview rollout → GPU Preview → Enable in Viewport.

Column
width60%

Image Added

 

Manual Explosion Setup

...

Section
Column
width40%

Let’s take a look at setting up a gasoline explosion simulation manually.

 

If you are continuing from the preset steps above, select the Simulator and press the Delete the Cache Files button from the Phoenix Toolbar and then delete the Simulator and the source objects from your scene.

Column
width60%

Image Added

 

 

Section
Column
width40%

If the sphere has been deleted, create a new Sphere with a Radius of 24.0 meters.

 

Click on the Create a Fire/Smoke Simulator button in the Phoenix Toolbar and click and drag in the viewport to create a volume to encompass the sphere, while leaving some room for the explosion to spread. Move the sphere near the bottom of the Simulator's volume space. Make sure the sphere is still inside the volume.

Open the Grid rollout and set the following values:

  • Scene Scale: 1.0.
  • Cell Size: 1.0 m.
  • Size XYZ: [ 229, 219, 123 ].
UI Text Box
typenote

Use the Size attributes of the Simulator as opposed to simply scaling the Simulator container with 3ds Max's Scale tool, as that may adversely affect the simulation.

Column
width60%

Image Added

Image Added

 

 

Section
Column
width40%

Click the Create a Fire/Smoke Source button on the Phoenix Toolbar and place the source in your scene.

UI Text Box
typenote

The Source object is a 2D non-renderable icon, so size and placement are only important for being able to select the Source when needed.

Column
width60%

Image Added

 

 

Section
Column
width40%

With the Fire/Smoke Source object selected, go to the Modify Panel and click the Add button located under the Emitter Nodes list, then select the Sphere.

This way the sphere will be selected as an emitter.

UI Text Box
typenote

The Source node is where we control the Emitter properties, like the Emit Mode ant the Outgoing Velocity. The sphere is the actual emitter of the fluid inside the Simulator.

Column
width15%

 

Column
width45%

Image AddedImage Added

 

 

Section
Column
width40%

Within the Fire/Smoke Source menu, we will disable Temperature and Smoke, as they will not be needed for this demonstration. Make sure Fuel is enabled.

Column
width60%

Image Added

 

 

Section
Column
width40%

Since we are creating an explosion that will use a large amount of fuel very quickly, we will need to increase the Outgoing Velocity. The higher this number, the more fluid will be generated per second. In order to create the short but powerful burst of fluid, we will animate the Outgoing Velocity number.

Make sure you're at Frame 0, turn on Auto Key, and change the Outgoing Velocity value to 2000.

Column
width60%

Image Added

 

 

Section
Column
width40%

Move to Frame 1 and change the Outgoing Velocity to 0.0, then turn off Auto Key.

Column
width60%

Image Added

 

 

Section
Column
width40%

Select the Simulator. In the Modify Panel under the Grid rollout are located the parameters to control the resolution of the volume grid, which greatly affects the look and performance of the simulation.

Currently, there are about 6 million Total Cells. To save on simulation time during the iteration process, click Decrease Resolution several times until the Total Cells are around 825,000.


For more information regarding simulation resolution, please refer to the Basic Liquids QuickStart page.

Column
width60%

Image Added

 

 

Section
Column
width40%

 

Page Contents

Table of Contents
stylecircle

 

Introduction

This tutorial covers the basic workflow for creating a gasoline explosion simulation in Phoenix FD for 3ds Max. By the end of it, you will be able to create your own explosion simulation and know the basics of editing some of the main settings of the sim.

To follow this tutorial, you will need to have the Phoenix FD for 3ds Max plugin installed. This tutorial is a companion to go along with the QuickStart video posted on our YouTube channel and available here:

 

Align
aligncenter
HTML
<iframe width="960" height="540" src="https://www.youtube.com/embed/YUcNZ-jT_ek" frameborder="0" allow="autoplay; encrypted-media" allowfullscreen></iframe>

Tutorial Assets

To download the files used in the last part of this tutorial, please click the button below.

 

UI Button
sizelarge
icondownload
titleDownload Project Files
urlhttps://drive.google.com/uc?export=download&id=1ZR3q5WnGyX9R1D9gNay_GvecIyLP9dTe

Tutorial Steps

This tutorial shows how to create a gasoline explosion simulation with both the toolbar preset and manual steps for greater flexibility and control.

Units Setup

We will begin by first adjusting the scene units.

To prepare your scene for rendering an accurate large-scale explosion simulation, make sure you are using appropriate scene units. For this example, we will be using meters. Scene units can be accessed through Customize > Units Setup.

 

...

Column
width10%

 

Column
width40%

Image Removed
Display Units set to Meters.

 

...

width40%

Image Removed
System Units set to 100.0 cm

Column
width10%

 

 

Create a Sphere with a Radius of  24.0 meters. This sphere will be the source of the explosion.

Image Removed

With the sphere selected, click and hold on the Explosion preset button from the Phoenix FD Toolbar to expand the drop-down menu. Select the second icon, which is the Gasoline Explosion preset. 

Image Removed

Now click the Start Simulation button in the toolbar.

Image Removed

Click Stop Simulation to halt the simulation as it starts to expand beyond the container.

 

Image Removed

 

 

The simulation is complete.

 

Image Removed

 

 

Manual Explosion Setup

Now we did that easily by using the gasoline explosion preset, so let’s take a look at setting this up manually to have more control.

If you are continuing from the preset steps above, select the explosion simulator and source objects and delete them from your scene. Make sure to go to the Phoenix Toolbar and delete the previous simulation cache.
 

Image Removed

 

 

If the sphere has been deleted, create a new Sphere with a Radius of 24.0 meters.

Click on the Create a Fire Simulator button in the toolbar, and click and drag in the viewport to create a volume to encompass the sphere and leave room for the explosion to spread. The volume should be about 229 x 219 x 123m.

...

If necessary, adjust the size of the grid volume using the X size, Y size, and Z size parameters in the Grid rollout. Don't scale the grid with 3ds Max scaling tools as this will disrupt the relationship between the Cell size and X/Y/Z size parameters.

Move the sphere near the bottom of the simulator's volume space. Make sure the sphere is still inside the volume.

Image Removed

Look in the Grid section of the Simulation properties. Currently, there are about 6 million total cells. To save on simulation time during the iteration process, click Decrease resolution several times until the total cells are around 825,000. For more information regarding simulation resolution, please refer to the Basic Liquids QuickStart page page.

Image Removed

Click the Create a Fire Source button on the toolbar and place the source anywhere in your scene.

 

Image Removed

 

 

In the Command Panel for the Liquid Source object, click the Add button and select the sphere. This will add the sphere to the Emitter Nodes list, enabling the sphere to be the emitter of the liquid.

 

Section
Column
width10%

 

Column
width40%

Image Removed

 

Column
width40%

Image Removed

 

Column
width10%

 

...

Image Removed

 

 

Since we are creating an explosion that will use a large amount of fuel very quickly, we will need to increase the Outgoing Velocity. The higher this number, the more fluid will be generated per second. In order to create the short but powerful burst of fluid, we will animate the Outgoing Velocity number. Make sure you're at Frame 0, turn on Auto Key, and change the Outgoing Velocity value to 2000.
 

Image Removed

 

 

Move to Frame 1 and change the Outgoing Velocity to 0.0, then turn off Auto Key.
 

Image Removed

 

...

Click the Start Simulation icon, and notice that the explosion does not happen. Select

...

the Fire/Smoke Simulator

...

 and navigate to

...

the Fuel

...

 rollout.

...

Select Enable Burning.

...

Column
width60%

Image Modified

 

 

Section
Column
width40%

Once again, if you

...

click Start Simulation, you will see that the explosion is still absent. This is due to

...

the Ignition Temperature

...

 being set

...

at 600.0. This temperature is rather high. By default, Phoenix

...

uses 300.

...

0 as a default ambient temperature. Change

...

the Ignition Temperature to a value slightly lower: 290.0.

Column

...

width60%

Image Modified

 

 

Section
Column
width40%

Start the

...

simulation and you will see a puffy preview. To see the explosion more clearly, navigate to

...

Image Removed

 

...

Column
width5%

 

...

width45%

Image Removed
GPU Preview disabled

...

the Preview rollout and turn on the GPU Preview by clicking Enable in Viewport.

Column
width

...

60%

...

Image Added

...

 

...

 

 

Section
Column
width

...

40%

Currently, the explosion is being cut off at the top and sides by the

...

Simulator's Grid.

Adjust this in the Grid

...

rollout by turning

...

on Adaptive Grid

...

 by Temperature. Lower

...

the Threshold

...

 temperature to 600.

...

0 to ensure expansion based on the temperature of the fluid inside when it meets the specified threshold.

...

UI Text Box
type

Image Removed

 

 

...

note

If you experience clipping of your smoke, set adaptive to Smoke with a Threshold of 0.02.

Column
width60%

Image Added

 

 

Section
Column
width40%

To prevent the explosion from expanding the bottom,

...

go to Container Walls and select Jammed (-)

...

 in the Z axis

...

. This will act as a floor. 

Column
width

...

60%

...

Image Added

 

 

Section
Column
width40%

Start the

...

simulation. The resulting explosion looks very uniform.

Column

...

width60%

Image Modified

 

 

Section
Column
width40%

To add variation, select

...

the Fire/Smoke Source

...

 and increase

...

the Noise

...

 value to 10.

Notice the variation

...

that is added to the simulation.

Column
width

...

60%

...

Image Added

 

...

 

Section
Column
width40%

Start the simulation once more. While it is running, select the Simulator and go to

...

the Rendering

...

 rollout and

...

click on the Volumetric Options button.

Column
width60%

Image Added

 .

...

 

Section

...

Column

...

width

...

40%

Under

...

the Fire

...

 settings, there are a few

...

 Fire Opacity Modes

...

 available: Use Smoke Opacity, Fully Visible,

...

 and Use Own Opacity.

...

Select Use Own Opacity, and stop the simulation.

When you

...

use Own Opacity mode, the fire curve will control the opacity of the fire instead of the intensity. The intensity in this mode is controlled by the color gradient and can be boosted or lowered using the

...

 Fire Multiplier. 

Column
width

...

60%

...

Image Added

 

...

 

Section
Column
width40%

The graph here controls only the opacity of the fire. Double-click to add a new point to the curve and drag it down to reduce the opacity of the fire, revealing more of the internal fire content and making it look brighter. Drag the point up to increase the opacity and hide more of the internal structure. Add points in the middle for a gentle curve.

Click

...

the Expand

...

 button for a larger graph to work with.

Column
width60%

Image Added

 .

...

 

Section

...

Column

...

width

...

40%

You can further adjust the opacity with

...

the Opacity Multiplier

...

 above the graph. For this example, we will lower this value

...

to 0.5,

...

 and notice how the fire increases in brightness.

Column
width

...

60%

...

Image Added

 

...

 The

Section
Column
width40%

The Physically Based

...

 setting blends between artistic and physically accurate results.

...

Change Physically Based

...

 to 0.75

...

 and observe the more "fiery" look in the simulation. This parameter balances between how much of the fire intensity comes from the color gradient plus the fire multiplier versus how much is calculated using the physically-based black body shader.

Column
width

...

60%

...

Image Added

 

...

 

Section
Column
width40%

To change the color of the fire, double-click on the carrots above the graph and select a new color.

...

Select Cancel

...

 to return to the previous color.

Column
width

...

60%

Image Modified

 

...

 

Section
Column
width40%

To adjust the explosion to look less contained, navigate to

...

the Dynamics

...

 rollout and

...

under Conservation, adjust

...

the Quality

...

 setting. This setting allows the simulation to spread more and gives it a swirling motion.

...

Increase Quality

...

 to 80. Note that increasing this value will increase simulation time. Start another simulation.

Column
width

...

60%

...

Image Added

 

...

 

Section
Column
width40%

The explosion is breaking up a bit more, but it's not quite there yet. Open the

...

 Volumetric Options

...

 in the Rendering

...

 rollout again. Disable

...

the Fire

...

 for now. We can see there is a lot of smoke as a result of the fuel burning so much. Stop the simulation to address

...

this.

Column
width60%

Image Added

...

 

...

 

Section
Column
width40%

In

...

the Fuel

...

 settings of the simulation, reduce

...

the Smoke Amount

...

 to 0.

...

4 to allow for more burning and a brighter fire, and also increase

...

the Smoke Threshold

...

 to 1.0. The smoke threshold will lessen how much of the fuel is created as smoke.

...

Reduce Propagation

...

 of the fuel

...

to 2

...

 to reduce how fast it propagates through the simulation.

Column
width

...

60%

...

Image Added

 

...

 

Section
Column
width40%

In

...

the Volumetric Options, remember to set the Fire'

...

s Based on

...

 parameter back

...

to Temperature

...

 before restarting the simulation.

Column
width

...

60%

...

Image Added

 

...

 

Section
Column
width40%

The fire now looks too hot.

...

Go to the Fuel

...

Image Removed

 

Section
Column
width5%

 

Column
width45%

Image Removed
Energy: 10.0

 

rollout and reduce the Fuel's Energy to 5 and restart the simulation.

Column
width60%45%

Image Added

Image Removed
Energy: 5.0

Image Added

 

...

 

Section
Column
width5%

 

...

40%

The explosion is starting to look good, but it stays hot for too long. We need to increase the cooling of the fire by going

...

to Dynamics rollout and

...

increasing Cooling

...

 to 0.3.

Column
width

...

60%

Image Modified

 

...

 

Section
Column
width40%

Our smoke looks very thin.

...

In Volumetric Options, expand

...

the Smoke Opacity

...

 rollout and

...

increase Simple Smoke Opacity

...

 to 0.9.

...

Column

...

width

...

section
60%
column

Image Added

 

...

 

 
5%
Section
Column
width45%50%

 Image Modified
Simple Smoke Opacity: 0.5 

Column
width45%50%

 Image Modified
Simple Smoke Opacity: 0.9

 

...

 

Section
Column
width5%

 

 

...

40%

Expand

...

the Smoke Color

...

 rollout and reduce

...

the Constant color

...

 slightly to make darker smoke. In this example, we used

...

a Value

...

 of 29. Also, lower

...

the External Scatter Multiplier

...

 to 0.8

...

 so that the light inside the smoke scatters less.

Column

...

width60%

Image Modified

 

...

 

Section
Column
width40%

The fire looks a little weaker now. Under

...

the Fire

...

 rollout in Volumetric Options, increase the

...

 Fire Multiplier

...

 to 5.0

...

 so the fire is hotter inside the explosion.

Column
width

 

60%

Image Added

 

Rendering

...

section
Section
Column
width40%

To prepare your scene for rendering a simulation make sure V-Ray is set as your Renderer in the Render Setup window.

Column
width60%5%

Image Added

 

...

...

 

...

 
Section
Column
width45%40%

Here is how the render looks so far.

 Image Removed

 

Column
width5%60%

 Image Added

 

...

 

Rendering

Make sure V-Ray is set to the current renderer in Render Setup. Render the result.
 

Image Removed

 

Image Removed

...

Section
Column
width40%

We need a ground plane, so create a floor by navigating to

...

the Create menu

...

→ VRay → VRay Plane, and place it in the scene. Set it a little lower than the simulation and give it a gray color

...

.

...

section
Column
column5%
width
width
60%

Image Added

 

...

 

Section
Column
width45%40%

Do another render.

Image Removed

 

Column
width60%45%

Image AddedImage Removed

 

...

 

Section
Column
width5%

 

 

 

40%

Notice some areas of the floor are too bright. You are able to control this

...

in Volumetric Render Settings, under

...

the Fire

...

 rollout.

Set the

...

 Light Power on Scene

...

 value to 0.5

...

 and re-render the frame. By reducing this value, the light is more evenly distributed.

...

section
Column
column5%
width
width
60%

Image Added

 

...

 

Section
Column
width45%40%

Here is the new render.

Image Removed

 

Column
width60%45%

Image Added

Image Removed

 

...

 

Section
 
Column
width5%
40%

 

To get finer detail for a final render, increase the

...

Resolution of the Grid. In the Modify Panel of the

...

Simulator, go to the Grid rollout and click

...

 Increase Resolution

...

 a couple of times to have

...

about 6.1 million Total cells

...

 and re-run the simulation.

Column
width60%

Image Added

 

...

 

Section

...

Column
width

 

Final render.
 

Image Removed

 

Applying the Sim Setup to a Real-World Example

...

40%

Here is how the final render looks.

Column
width60%

Image Added

 

Example Scene

...

Section
Column
width40%

Now let's apply what we've learned to a real-world example and make these barrels

...

explode!

The following scene file can be downloaded from the Overview section above.

Column
width60%

Image Added 

 

...


Section
Column
width40%

To do this part of the tutorial, download the tutorial file as instructed at the start of this page.
 

Image Removed

 

...

Select the blue barrel, pCylinder3, and apply

...

the Gasoline Explosion Preset.

Column

...

width60%

...

Image Added

 

...

 

Section
Column
width40%

Select the Simulator and change

...

the Cell Size

...

 to 0.03 meters. This will decrease

...

the Total Cells

...

 to around 573,

...

000 and will save you time during the iteration process.

Column
width60%

Image Added

...

 

...

 

Section
Column
width40%

Start a simulation and you'll see that the blue barrel explodes. Now we will focus on the other barrels.

Stop the simulation and select

...

the Fire/Smoke Source. Shift-drag to create a copy.

Column
width

...

60%

...

Image Added

 

...

 

Section
Column
width40%

In

...

the Fire/Smoke Source, Add

...

 the red barrel, pCylinder2.

Notice that this barrel laying on its side is slightly outside of the Fire/Smoke Simulator. Select the Simulator box and move it over to hold all three barrels.

Column
width

...

60%

...

Image Added

 

...

 

Section
Column
width40%

When you start the simulation now, you will see that both barrels explode at the same time.

Stop the simulation.

...

Column
width60%

Image Added

...

 

...

 

Section
Column
width40%

To offset the second explosion so that it looks like a chain reaction, select the

...

second Fire/Smoke Source

...

 and navigate to its keyframes. Select both keyframes and drag them over so that the explosion is triggered

...

at Frame 5.

Column
width

...

60%

Image Modified

 

...

 

Section
Column
width40%

To make sure the explosion is not triggered earlier, step back

...

to Frame 4, turn

...

on Auto Key, and change

...

the Outgoing Velocity

...

 of the Fire Source

...

 to 0. Then turn

...

off Auto Key.

Column

...

width60%

...

Image Added

 

...

 

Section
Column
width40%

Now when you start the simulation again you will see two explosions, the second being delayed by five frames.

Stop the simulation.

Column
width

...

60%

...

Image Added

 

...

 

Section
Column
width40%

For the third barrel, shift-drag the

...

second Fire/Smoke Source

...

 to make a third copy and

...

add pCylinder1 to it.

Column
width60%

Image Added

 

...

 

Section
Column

...

width

...

40%

For this last barrel we are going to let the explosion cool off some before ignition, so with the

...

third Fire/Smoke Source

...

 selected, move the timeline

...

slider and the source's keyframes up to Frame 40.

Column
width60%

Image Added

 

...

 

Section
Column
width40%

Turn on the Auto Key and navigate the slider to 41st frame. Change the Outgoing Velocity to 60.0.

Column
width60%

Image Added

...

 

...

 

Section
Column
width40%

Start the simulation and let it run. The third explosion starts as the first two are cooling off.

Do a test render to see the results.

...

If the fire is too bright, go into the Volumetric Options and decrease the Fire Multiplier value.

Column
width60%

Image Added

...

 

...

 

Do a test render to see the results. If the fire is too bright, go into the Volumetric Options and decrease the Fire Multiplier value.
 

Image Removed

 

Section
Column
width40%

Go to the Volumetric Options → Fire tab and change the Light Power on Scene to 0.1.

Column
width60%

Image Added

 

...

 

Section
Column
width40%

...

To make the final simulation, go into

...

the Grid

...

 rollout and increase

...

the Cell Size

...

 to 0.015 meters. This will increase

...

the Total Cells

...

 to about 4.5 million.

Set the Adaptive Grid to Smoke and the Threshold to 0.002.

Column
width

...

60%

...

Image Added

 

...

 Restart the

Section
Column
width40%

Run the final simulation and make a final render.

...

Column

...

width

 

 

 

...

60%

Image Added