Shatterer Tool surface node

Shatters and animates pieces of geometries especially in Procedural Building Destruction

The Shatterer Tool is an user-friendly tool to shatter and animate shattering in a efficient and easy way especially in the simulation of Building Destruction.

Using Shatterer Tool - The Basic Workflow

The user that wants to develop a scene with the Shatterer Tool has to be follow some easy rules to make it work properly

1. create a 2D grid

2. import it into the shatterer tool
3. position the cutter

4. add the internal points

5. perform the cutting and the shattering

6. pass on the Dynamics Manager or the Output
7. if passed to the Dynamics, set up the motion in auto or manual mode
8. in manual mode position the bombs

9. simulate the shattering

Tips

Once the HDA has been imported one or more grid have to be placed with in mind how the final design of the object has to be. For example, if a simple building has to be shattered, four grids has to form the main external walls, then can be added more for the floors and the roof and the internal walls.
Each of these grids has to be as much clean as possible (no internal points or edges).
The grids can have internal holes, but this could produce some random problems.
Each grid has to be grouped. If more then one grid, for example the grid that form the windows of a singular facade, lie on the same plane, they can be grouped all together, otherwise no.
The design of the object has to consider that the extrusion is calculated on the opposite direction of the original normal of each grid.
If some of the grids are not part of the possible destruction, for example a wall opposite to the shattering part, it is advised to merge it after the HDA node. Each group more imported in the HDA will increase the computational time of the shattering operation.
The user is invited to use in moderation the options especially during the shattering, because many recursive operations could cause problems. In particular in the Add Points and Level of Details is better to start from small numbers and try to increase one number per time.
If Add Points and Level of Detail don’t produce anything nice try to enlarge the size of the initial 2D group
One general rule is to save quite frequently especially during the shattering operations, because Houdini could crash quite frequently too.
During the dynamics phase, if the number of chunks is more than 700 it can take a couple of minutes to cook the operations, depending on the power of the machine.
Once found the best motion or to find it, it is suggested to save the simulation like a series of bgeo file on disk.
To create irregular cuts with half broken natural chunks, not select all the chunks during the Positioning phase in manual mode but just some.
In the Positioning phase in manual mode do not overlap the various boxes.

Parameters

Tool

This is the main menu and it commands what the HDA is doing.

Shatterer	this option activates the first submenu and the relative operations. With this option is possible to transform a simple grid or any 2D primitive in a 3D shattered piece of geometry.
Dynamics	this option activates the second submenu and the relative operations. With this option is possible to set up the motion options.
Output Pieces	this option activates the third submenu and allows the user to have and external output of the shattered object.

Shatterer

Number of Pieces

This label shows the number of pieces in which the initial grid has been shattered.

InitialGroups

With this option is possible to import the group/groups to be shattered.

Phase

This is the main menu of the Shatterer operation.

Cutter Pos	with this option activated the Cutter folder is activated and is possible to position the cutter
Add Points	with this option activated the Add Points folder is activated and is possible to decide the number of points to add in the initial primitive/s
Shattered Geo	with this option activated the Shattered Geo folder is activated and is possible to decide some options about the shattering

Cutter

Cut Type

the cut can be a 3D piece of geometry or a plane

Cut Position

in the case a plane has been chosen like cutter, it is possible to decide if the cut has to be done above or below the plane position

Depth

the depth of the 3D cutter

Rows

the number of the internal rows of the cutter

Columns

the number of the internal columns of the cutter

Translate

a 3D vector that allows to translate the cutter

Rotate

a 3D vector that allows to rotate the cutter

Scale

a 3D vector that allows to scale the cutter

Height

the displacement height of the noise function of the cutter

Roughness

the fractal roughness of the noise function of the cutter

Fractal Depth

number of iterations of fractal brownian motion noise of the cutter

Frequency

noise frequency of the cutter

Noise Type

Perlin Noise	Standard noise which performs a 3 dimensional hermite spline interpolation on a lattice of random values.
Sparse Convolution	Scatters points randomly through space and interpolates their values.
Alligator Noise	A variation of sparse convolution which gives higher frequency discontinuities.

Add Points

Seed	the seed control the number of points bricked on the primitive
Offset	a 3D vector control the amount of offset to apply to the bricking operation

Note

The number of points will affect the shattering result

Shattered Geo

Type

the type decide how the shattered object has to be considered

Like Glass	if this option is activated the shattered geometry has got a thin structure, like glass
Like a Building	if this option is activated the shattered geometry has got a thick 3D structure, like a building (this option will be used later to perform a self collision detection)

Level of detail

control the quantity of pieces in which the initial group/s is shattered

Internal Division

decide if each shattered piece has to be divided again internally

Distribution Direction

Standard	the standard distribution is random in any direction
Horizontal	the orizontal distribution is random but favour the horizontal one
Vertical	the vertical distribution is random but favour the vertical one

Value

control the distribution

Colour Pieces

if the avarious shattered pieces has to be colourized

Thickness

the value of the thickness of the extrusion

Dynamics

Number of Pieces

number of shattered pieces

Phase

Preview	in the preview phase the motion of the pieces is substituted by the one of particles that is shown drawing some lines
Simulation	in the simulation phase the actual pieces motion is shown

Physics

Gravity	gravity value
Mass	value that multiply the actual internal mass value depending on the size of the pieces

Motion

Initial Acceleration	the initial impulsive acceleration value with which the pieces start their motion
Rotation	if the pieces have to have any rotation during their motion
Velocity Rotation	the initial velocity value of the rotation
Start Rotation at Frame	control the frame at which the rotation has to start
Stop Rotation at Frame	control the frame at which the rotation has to stop
Stop Rotation Bounces	control after how many bounces the rotation has to stop

Note

The start and end rotation parameter depends on the actual start of the motion of the pieces. If it has been set up the start of the motion at the frame x and the rotation at the frame 3, the rotation will start at the frame x+3. These options are cumulative, the first that is validated annuls the others.

Interaction

Drag Pieces	value that controls how much the pieces are dragged in their motion by their mass
Pieces Interaction	if the pieces have to interact each other
Level of Interaction	the value of interaction among the pieces
Acceleration Interaction	the initial acceleration with which the pieces repel each other

Collisions

Ground Collision	to import the sop to be used like ground collision
Ground Tollerance	the tollerance value between the pieces and the ground, resolves the problem of penetration in the ground
Self Collision	if the self collision is activated or not. It works if in the Shatterer/Shattered_Geo/Type menu is chosen Like_Building
Bounce Gain Normal	the value that control how much the pieces have to bounce in the normal direction
Bounce Gain Tangent	the value that control how much the pieces have to bounce in the tangent direction
After Bounces	what the pieces have to do after the bounces. Stop or continue sliding on the ground surface.

Explosion Parameters

The explosion parameters is the section where is possible to set up how the particles will move

Explosion Method

two different methods: auto will decide automatically where to direct the explosion (normal direction of the original primitive), manual make the user decide the direction and what pieces to move

Explosion Frame

the frame at which the explosion starts

Explosion Phase

when in manual mode

Positioning	make position the bombs to control when and what to make explode
Done	activate the changes done during the Positioning

Bombs

decide how many bombs to place to control the explosion

Translate

control the translation of the bombs

Rotate

control the rotation of the bombs

Size

scale the bombs

Explosion Frame

the frame at which the explosion starts

Output Pieces

Output

decide what output

Whole+Shattered	output both the whole part and the shattered pieces in different groups
Whole	output just the whole part
Shattered	output just the shattered pieces

Note This operation bypass the dynamics operations

Render

Render Mode

it allows the user to have the original objects until the shattering starts. If the shattering has been set up at frame x, the shattered pieces won’t appear until frame x, and that works also when different shattering timing is added to different groups.

Normals

the points of the output groups have

Original	the same normal of the original 2D primitive
No Normal	don’t have any normal
Random	have got a normal with random direction

Main Crack

if the main crack between the whole part and the shattered one has to be shown

Usages in other examples

Example name	Example for