Dusty Explosion

In this tutorial we are going to use particle flow to create a an explosion of chunks large, small, and fine dust.

While I stand my ground and say that you will never get a nice volumetric effect using the standalone 3DS package over a fluid simulation plug-in like Fume FX... the principles still apply and will be very useful to you in the future when learning new software. Also the Chunkier stuff we will create in this tutorial will be useful when combined with a volumetric fluids simulator.

This is a rather large task, so I am taking some of the simpler bits out of the equation like textures and the creation of necessary space warps and deflectors. If you don't know how to make these things yet then I recommend to wait until you do for this tutorial. To start this tutorial I am going to ask you to download and unpack a .zip folder with a starter scene, and a couple of image textures. You will have to reassign the these images to the provided texture in order to get same effect. You will find the download available by clicking the link below -

http://animation.diclementi.com/tutorials/explode1_start.zip

Inside it you will find a ground plane, and a matching deflector so our chunks don't fall through the world. 2 Wind Space warps with different turbulence settings which we will use to add variety to the movement of the particles, a Gravity to make them fall back to earth, and a Drag to add some resistance as they do. You will also find a Group called Fragments which is nothing more than a cube I fractured using the free script available on the internet called "FractureVoronoi_v1.1". as our fragments are already created you will not need the Script for this tutorial, but for future use you can find and download it for free here-

http://www.scriptspot.com/3ds-max/scripts/fracture-voronoi

Ok, now we can get started on building our effect. Open up the explode_start.max file to begin. We will start by reassigning the texture paths to your local computer.

Press Shift+T, or click on the Big Green 3DS Button in the top left corner of the program, and go to References-> Asset Tracking. The Asset Tracking window will appear and should look something like this:

Hold down Ctrl and select both of the images titled dustball1.jpg and dustball1_mask.jpg they will highlight blue once you have done this correctly. Then right click over them and select Set Path... from the quad menu.

A file open dialogue will appear, simply find where you saved the two images I had you download and hit ok.

This will reassign the file paths referencing these images to your own computer setup, as I have probably saved mine in a different location than you did.

Once the paths are reassigned just close the Asset Tracking window. Then press (6) to open particle view, or find it under the Graph Editors menu.

Drag an Empty flow from the Depot at the bottom of the window and drop it in the empty light grey stage area to begin, then select the PFSource 001 title on the box it creates to adjust the particle system settings.

Next, drag and drop a birth operator underneath this first box in the light grey stage area and connect the two boxes by dragging the blue node to the empty circle node on the second Event 001 box. Select the Birth and adjust its settings in the command panel to the right.

We will start with the larger chunks of our explosion so the amount will be lower, I have chosen 20. I also timed my explosion so that it starts emitting our particles at frame 15, and stops 1 frame later at 16.

Next drag and drop a Position Icon between our Birth and our Display 001 operators in our first Event Box.

Set the Location dropdown to Pivot so all our particles begin in the center of the icon.

We are going to have 2 different textures for this effect for the purpose of this tutorial, so we will start with just a flat grey texture I have named in the Material Editor for you... to simplify I have made no changes to the standard texture but in the future you can texture these chunks any way you like ... concrete, stone, dirt, glass, etc.

Drag and Drop a Material Static from the depot underneath the Position Icon we just made. Then drag the first texture in the material editor named Grey Mat to the empty channel box in the command panel.

Next we want to use the fragments I have made using the Fracture script. Drag and drop a Shape Instance below the Material Static, then click the None button and then find the group named Fragments to the Shape Instance settings.

Add the "fragments" group here

Make sure to mark "Group Members" so that it separates the chunks for us automatically as particles.

Mark Multi-Shape Random Order to randomize the chunks

Then Drag and drop a Speed operator below the Shape Instance.

I gave mine an initial speed of 225 with a fairly large variation of 150 so we toss chunks everywhere. Adjust this to your liking.

Be sure to check the Reverse box or they will shoot straight down rather than up and over.

Add a divergence of 45, give or take to your liking so they won't just fly straight up, but will leave the axis in many directions from the original direction.

Next, drag and drop a Force operator below the Speed and add your gravity in your scene via the By List button to the space warps list in particle view.

I have given the gravity a strength of 0.5 ... change this to your liking if you wish the particles to fall faster increase, slower decrease.

In order to see how our large chunks are working, select the Display 001 operator, and change the top dropdown menu to Geometry. Then scrub across your timeline to see how they look.

They are a bit large even for the large chunks, we can fix that by adding a Scale operator under our Force.

You can adjust these to your liking I have opted to skinny mine up a bit and shrink them.

Unmark Constrain Proportions if you wish to adjust each axis% separately ... I wanted mine skinnier so I shrank X and Z by 50% and Y to 10%.

I also told them they could vary by 50% in all directions so we get more of a variety.

I don't know about you guys, but every time I see something explode the chunks spin all over the place rather than stay straight up and down. So the next thing we will add will be a Spin operator below our Scale.

These are the big heavy chunks, so I don't want them to spin like crazy or it will seem as if they are lighter than I want them to feel. So I reduced the rate from 360 to 200 and gave them a Variation of 100 to randomize the spinning.

I set the dropdown to Speed Space Follow so they mostly spin in the direction they are traveling, but added a 1.0 in all 3 Axis values so they are allowed to vary a bit.

I can further create a sense of chaos by adding a Rotation operator next. It's default of Random 3D will do just fine... this will start our particles out in different directions right off the bat and give it a better sense of randomness.

Now our chunks are starting look explody ... but they hit the ground and fall right through it.

So next we will add a Collision operator below the rotation and using the By List button in its settings we will add the Deflector from the scene.

Add the Deflector here...

Look at the settings in the modify tab that I have assigned to the deflector.

I gave it a bounce of .5 so they didn't shot back up like a rubber ball, and because an explosion is pure chaos I increased the Variation, Chaos, and Friction to add variety to the collisions.

Mark this collision to allow it to Collide with particles multiple times. Adjust the value to your liking, but I think the default of 5 will work out fine.

As the Collision is a test, it comes equipped with a new blue node hanging off the side of it. This means we can send it to a new event where we can tell the particles how to land and come to a standstill ... rather than what they are currently doing which is spinning in place indefinitely.

Drag a new Speed operator up and drop it in the empty light grey stage area below our first Event 001 box.

In order to get our particles to settle down to a stop after bouncing a couple of times ... we set this speed to 0.0 with no variation.

Next you can copy the material static operator from the Event 001 box down to this one. Hold Shift until you see the + sign hovering above your mouse cursor ... the click and drag the Material Static operator from the First event box, to the second below the speed.

When the Copy dialogue appears, you can mark it as an instance since we want the same texture no matter what changes we make to appear on our chunks flying through the air, and landing. Change the new Display operator to Geometry as well.

They now come to a halt but are still rotating in place, so add another Spin operator below the Material Static we just copied down.

Reduce the Spin rate to 0 to get them to stop.

Great, now our chunks fly out with force, fall and land coming to a stop...

next, we will go back up to our Event 001 box and add a Spawn to the bottom of the list, this spawn we will use to create a fine dust cloud that trails behind our big chunks to give it a bit more power and depth. Before you add the spawn, I recommend putting your timeline scrubber back to 0 so your computer doesn't lag out and crash before we get to the settings.

Set the spawn to by travel distance, with a step size of 3.5 ... if it's too sparse for your liking decrease, if it is too heavy ... increase

Give the Inherited speed a value of 25 and a variation of 50 percent so the dust trails behind but still acts random.

Also give it a Divergence of 35 to mix it up a bit and not have them follow in a straight line.

So that we don't crash our machines and can continue and check out what we have done with ease, let's start the next event by adding a Delete operator in the empty light grey stage area underneath the Event 001 box. This will kill off our trails before they crash everything due to infinite spawning particles.

Set it to By Particle Age and give it a life around 75 or so

Now is also a great time to change the Display 003 operator in this event to Geometry so we can see what we are doing.

Now that our delete is in place, we can build the dust particles above it, Drag and Drop a new Force operator to the position above the Delete.

As we make these effects more and more complex, we will be doubling up on lots of things ... in this case, we added a Force just for the gravity in our scene. So using the By List button, add the gravity again to this event.

This time however, reduce it's influence% to 50. down from 1000. This will make our dust feel a hell of a lot lighter than our original giant chunks.

They will gently float to the ground, rather than sink like a rock.

Next, we want to blow the dust about a bit and add some wind resistance. What wouldn't affect our larger chunks at all will drastically effect our dust cloud.

So add another brand new Force below the one we just made. Leave the influence at its default of 1000 this time, and add the Wind 001 and the Drag 001 from our scene to it, don't add both winds, just the first one. Be sure to check out the settings of these two space warps and see how I changed the turbulence in the wind, while the Drag I drastically reduced to 1% in all axis so that the resistance is very subtle.

We keep the gravity separate in this case so that we can make it less effective on the fine dust, over the large chunks without having to create different strengths of gravity icons.

Next, we need to give our particles a new shape... we don't want them to be chunks like we had before, so instead we are going to use a little trick with our second textures.

Add a Shape Facing operator to the list below the last force we just made.

Add the camera in the scene to empty channel button here... this ensures that all these faces will point at the camera in the scene giving the illusion of depth ... rather than actual depth.

Adjust the Units in the World Space size settings to 10.0 to make them bigger.

Mark the Orientation dropdown to Allow Spinning, so all our dust clouds aren't exactly alike.

Scrubbing back and forth along your timeline should now show our chunks trailing behind a bunch of smaller planes(or faces) We can adjust their size and variation by adding a new Scale operator to below the Shape facing we just made.

Set the Type to Absolute

We are actually going to animate this one via keyframing...

Set the Scale Factor Values to 2000.0

and the Variation to 30% or so.

and then.....

Turn on your Autokey... and move the scrubber to Frame 50 on your timeline.

Then raise the Scale Factor to about 4000% ... so that our dust grows with time.

Now we have to make our new faces look like dust clouds rather than colored planes.

Add a Material Dynamic to below the last Scale operator. Then drag and drop the second texture called Fine Dust Mat 1 to the channel button.

Be sure to take a look at the texture I have previously made for us.

In the Diffuse channel you will see a picture of a cloud of brownish colored dust, in the Opacity channel you will see a Mask texture ... the Map is a black and white version of the Dust cloud, and the Mask is a Particle Age map designed to fade the dust out over the life of the particle. All alone it is very faint and doesn't look like much, but add it to a thousand other simlar planes in 3D space and we will get the illusion of actual dust clouds fading and dissipating into the air. It will never look as good as a Fluids simulation but for the Standalone 3DStudio software it works fairly well.

Finally we want the dust to come to a settling point on the ground instead of falling through completely.

Add a new Collision to below the Delete in the Event 003 box next.

Add in our Deflector once again via the By List button here.

And mark it to allow multiple collisions, the default is fine again for our effect.

Congratulations you have created the first half of this effect. Slide the timeline scrubber to see how this effect is acting in your viewport and adjust any of the previous settings to your liking like more birth particles etc as you like.

We still have a lot of work to do, but by adjusting all the various Uniqueness Seed values throughout our operators, etc. you can find a good shape that you like.

Next, we need all the many little splintered fragments that come in between dust and chunks.

In order to accomplish this we are going to create an entirely new birth event... so Select all the flowchart boxes you have made thus far and scoot them over as far to the Left of the Particle View window as you can to make room for more!

Then drag a new Birth operator and drop it in the empty light grey staging area off to the right of our current events.

Just to give you a big picture image of what we have so far it should look rather extensive now... add your new Birth operator as shown and this time make the Emit Start and Stop match the first Birth, but we want about 500 or so particles in this new one.

We can copy over directly quite a few things from our original system by holding control to select more than one operator, and then hold Shift until you see the + sign above your mouse cursor.

Then click and drag them all over and drop them underneath our new Birth in the new Event 004 like above.

This time make sure to mark copy as we will be adjusting the settings as we go down the list and don't want them changing our original particles at all.

Then click OK.

We can leave some of them as is like the Position Icon, the Shape Instance, the Spin, and the Rotation. Others like the Speed and Shape Instance we will need to be varied a bit so we get some more variety with these smaller particles.

Select your new Shape Instance operator and adjust its settings to make smaller chunks rather than huge ones like before.

Mark the Scale checkbox, and reduce these particles to 10 or 15% of their original size.

Then give them a bit of Variation.. I chose 35%

Then move down and select your new speed to adjust it some.

Adjust the new speed 003 to slightly different values, I have chosen a speed of 170, a Variation of 200, and reduced the Divergence to about 40.0 ... just so we don't have our smaller particles following the larger ones exactly or as quickly.

Next, adjust your new Force operator's settings a bit by adding the second wind in your scene. These are going to be smaller chunks so the wind would affect them where it didn't on the huge chunks.

If you take a look at the Wind002's settings in the modify tab you will notice they vary from the original Wind001's by a bit... this adds more chaos and randomness to our new smaller chunks.

Now we can make our smaller chunks stir up some fine dust as they strike the ground. Put your timeline scrubber back to frame 0 as we are about to make a new Spawn and don't want to crash our computers.

Then drag and drop a new Spawn operator to the empty light grey stage area below our Event 004 box.

Leave this spawn set to Once, which is the default.

Make it so that only a fraction of the particles will actually kick up dust... I chose about 30%.

The rest of the settings can remain defaulted and should work nicely.

Now would be a decent time to go ahead and change the new Display 004 and 005 operators to Geometry instead of Ticks so you can see what's happening.

While we are still in this event we will make our new smaller chunks come to a stop as well. Use your Ctrl key to select the Speed, Spin, and Material Static operators from our Event 002 box, just like we did from the first event.

We can use all of these the way they are over again for the new smaller particles. It should bring them to a stop as they land on the ground.

Next we will make our Final Event by copying over the Gravity from our original Fine Dust to the empty light grey space below Event 005 box.

Hold Shift once again and drag and drop the Gravity with only 50% influence, to the empty spot in Particle view.

Then connect the Blue node from the Spawn in Event 005, to the empty circle node in Event 006 to tie them together.

Next, Add a new Speed operator to below the new Force.

This is just extra fine dust being kicked up when small particles land, so we don't need much... I chose 5 with a variation of 15.

Be sure to check the Reverse box so they float up a bit not down, and set some Divergence ... I gave mine about 40 to randomize it a bit.

Add a new Force below the Speed, and this time only add the Drag001 to the settings via the By List button.

Now would be a good time to mark the newest Display 006 operator to Geometry as well so we can see the next steps clearly.

Next from our original Fine Dust Event 003 box, we are going to copy over and adjust the Scale, Delete, and Material Dynamic operators. So once again hold Ctrl to select all three, then hold down shift till you see the + sign above your mouse cursor and copy them to below the newest Force.

This will copy all of our keyframing for the Fine Dust cloud scale up, so the new Scale and the new Material dynamic need no changes.

Select the new Delete however, and vary it's settings just a little bit. I chose a By Particle Age of 60, with a variation of 10 just to change the dust settling up a bit.

Almost there!! Only one thing left to do, and that's make sure our new dust doesn't fall through the Ground plane. We can actually copy the Collision from the same place we just copied the last 3 over. It's settings will do just fine and copying it saves us a few moments so that's always nice.

That should do it! You should now have a nice Explosion followed by a growing plume of dust and dirt...

Go back through and make any last minute changes and adjustments ... add some more particles, grow your dust a bit more ... the final tweaks I leave up to you!

To see a preview animation of the final effect, you can click here:

http://animation.diclementi.com/dustyexplosion.mov

24