Andres de Mingo kindly explains us the making of some complex effects using Pulldownit and FumeFX in 3dMax for his appealing destruction shot.

This project was about destroying a brick wall with an animated robot, I had done similar things in the past using Pulldownit and not difficult but this time I needed to create a thin long crack in the stucco before making the wall to collapse and in addition this crack should follow the trajectory of an animated  laser beam coming from the hand of the robot, that was the main challenge.

Making the laser beam crack

The laser is a simple thin cylinder in 3ds Max with the height value animated to make it grow towards the wall, besides the cylinder has a Octane material  with emission per blue color, in this way it can illuminate the scene and finally to make it shine I added glare and bloom to the cylinder as a post process with Octane render itself.

To fracture the wall in the shape of a circle I created a circle spline in 3ds Max and put it inside the stucco, then I used the path-based shatter feature of Pulldownit to create the fragments, with around 200 shards, but I wanted the center part of the wall to break later so I added a second local shatter pattern in the middle of about 70 shards.

For making the crack following the trajectory of the light beam, I used a PDI cracker object attached to the circle path, then adding some keys to make sure the cracker had the same speed of the laser and by playing the simulation I got this appealing effect done in seconds.

Only problem was the center part of the stucco was falling to the ground after it became isolated, to solve it I attached the stucco wall to the bricks behind by selecting the option “Attach Nearest” of PDI Fracture Bodies.

Hitting the wall

The brick wall is made of small cubes attached together as a single object, I discovered this is important to get it broken in the shape of bricks in dynamics, otherwise the wall breaks as a continuous surface. I used a similar setup than the stucco, this time I created two concentric circle splines in both sides of the wall of same size, and shattered the wall in around 1200 shards with path-based pattern, then adding a local shatter pattern of around 600 shards in the middle, in this way PDI created small fragments in the contour of the circles perfect to crack them. Also to get the bricks as separated objects after shattering the wall I had to check the PDI shatter option “detect mesh-groups”.

After getting the fragments created I made a fracture body for the whole thing including the stucco part and set it as static in PDI fractures options, also setting Clusterize to 0 to force the wall breaking only along the circle shapes.

I didn’t use the robot itself for this part of the shot, in its place I created a flat cylinder of the same size of the circle and animate it to hit the wall, so it pushed only  the fragments in the middle and hiding this object from rendering made the trick.

I rendered everything with Octane, because it is very fast and easy to use, maybe you have more features with other renderers but they takes much longer to get the final images ready.

Adding dust

After the PDi simulation was baked I started adding dust with Fume FX, I generated a slight wake of dust following the laser beam by simply emitting smoke from the same cracker object I’ve used before, as this object was already attached to the circle path that was easy.

For adding smoke to the wall when collapsing, I used Particle Flow in 3ds max to attach particles to the stucco fragments but only along the borders, I set around 1500 particles for this, then I set those particles as source in Fume.

Dust is heavier than the air so it must fall eventually to the ground, I played with gravity and buoyancy values until getting the desired look for smoke.

For rendering dust, I used Arnold because FumeFx  doesn’t support Octane, however at first I wasnt able to render fume with Arnold neither,  finally I had to convert the smoke to openVDB format and use an aiVolume with aiStandardVolume shaders with it, after that everything was pretty automatic except I had to set some parts of the robot that were in front of the smoke as matte shadow objects to render it correctly.

Dust was rendered in a separate pass and composed later in Fusion in this way it gives you a second chance to modify color and brightness to improve the look of the smoke.

Conclusions

It was a nice experience working with Pulldownit plugin, in this shot there were different stages for destruction, first the stucco crack, then the hole in the middle and finally the robot passing through the wall, maybe the most surprising to me was PDI can make all of this effects using the same set in one run, without having to resort to more complex setup like preparing and hiding partially destroyed models and replace them at some moment. PDi was pretty reactive allowing me to get the results in seconds, modify parameters and compute again, that was great.

Adding dust to fragments with pFlow and Fume FX was also quite easy and fast computing.

Thank you Andres for sharing your experience in our blog!

Andres de Mingo  the author of this powerful shot,  kindly explains us how he did the destruction effects using Pulldownit plugin in 3d Max.

Impact with the stacked boxes

Mi idea was to break all the boxes violently when impacting with the car but leaving the pallet below it sliding fast forward as  a whole,   I believe pulling it forward the camera  makes the sequence more impressive for the viewer. For setting the scene with PDi first thing was to define the shape of the fragments the boxes will break in,  no doubt, PDI wood shatter style was the natural choice,  however applying it to the box as  a whole the fragments on the top and bottom parts shattered  in round fragments , the reason was the wood pattern was aligned with the sides planks, to solve the issue I detached top and bottom parts as different objects so I could apply the wood pattern aligned with them correctly. I shattered each box in around 150 shards doing it in this way.

I set the pallet as a dynamic object and the car as a kinematic one but with convex hull shape to speed up collisions. I created a fracture body for each box, setting activation as first hit, hardness 100 units and clusterize 0. Besides the floor and ceil and several pillars was set as static objects so fragments doesn’t pass through them. I hadn’t to do any further change and PDi computed dynamics blazing fast for the  near 800 objects involved  at once.

Collision with the pillars

Shattering the pillars required   a little more care, I wanted them to stand but generating small fragments on the impact area with the car,  I wanted also small debris falling apart in the corners of the pillars with the ceil.  For the first one, which breaks in the background I simply combined two local shatter patters, one for the impact area and another one for shattering the top part of the object. For the other column which breaks  rather close to the camera I used  the new vertex color shatter which allowed me to make the areas of breaking more irregular and also generate easily random cracks over its surface when the car hits it.

I created a fracture body for each column, setting this time activation as breaks upon impact as I wanted the main part of the pillars  to stand,  as before the car was set as a kinematic object and the floor and ceil as static ones.  However in my  first attempt some big fragments broke off when impacting the car and I wanted them to stand, using PDI advanced fractures to set all big fragments as static objects fixed the issue, finally I did several test with different hardness values until achieving the desired  look for destruction.

Damaging the car

The car itself should deform when colliding with the pillars and its bodywork get damaged with scratches and dust because of the impact, to deform the car I used a morpth modifier in 3D max, setting 3 states for the mesh with different levels of deformation.  The bodywork material is animated , by one side its glossiness cuts down progressively because of the dust adhered to it and for adding the scratches I used a composite material and animated  the opacity of each component shaders to  show the scratches after collision.

Hitting the ground

When the car finally fall head down , there appears several fragments rolling over the ground, they are supposed to be debris from the ground and also small parts of the car itself. In place of shattering the ground and separating parts of the car I did a little trick, I created a thin box object over the ground textured like it and placed just where the car fall, a kind of step, I  shattered it in 200 fragments using uniform style, after that I changed the texture of some shards to be the same of the wind screen.  Then by setting a fracture body for this thin step when the car hitted it, the fragments rolled over the ground as I wanted.  I had just to hide this fake object until the car fall head down to get the effect done.

Adding smoke and dust

Smoke was generated using Particle Flow in 3d Max and applying a smoke material for the particles, as not being a volumetric smoke like the one generated by a fluids plugin its behavior is limited and even poor in foreground. So I set its gain very low in Fusion to hide the defects as much as possible but still being able to see the smoke in the scenery.

Dust was added by rendering a very blurred pass of the fragments in motion and adjusting its levels in Fusion, in this way you get a pretty dusty look of the fragments.

thank you Andres, very nice work!