car crash in the garage by Andres de Mingo

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!