Page 60 - 3D World - October 2017

TuTorials
Master destruction effects

BASE SCENE GEoMEtrY IMPort
01The Maya scene is a spaceship crashing through 02 In Houdini, go to Object mode. To add new nodes to the Network
a wall. To simulate it breaking, export the section of Editor, you can use the Tab menu. Press [Tab] to bring it up, type 'g' in the
the wall the ship passes through to Houdini. Select the search field and select Geometry from the list that appears. Double-click the
geometry, then Export Selection to Alembic. If your node to see its contents. Delete the File node that Houdini creates by default
geometry has UVs, check UV Write in Alembic Export and use the Tab menu to add an Alembic node in its place. In the Parameter
dialog. Select the shot camera, File>Export Selection to Editor, click the icon to the right of the File Name field and browse to the
export the camera as an FBX file. Alembic file you exported from Maya.

tHE WALL SoP
03The Alembic file
forms part of a SOP (Surface
OPerator) network. You can
see how to set the network up
at 00:50:40 in the video. The
Convert node converts the
Alembic file to a geometry
object, the Facet node
generates normals for it, and
the Null node references out
the result so that you can use
it in the simulation. When
your SOP is set up, go back to
Object mode.

Set up
proper uVs
Before you can hand a
simulation to a lighting
artist, your geometry
has to have proper UVs.
You can see how to set
them up at 00:54:45 in
the video.

tHE DoP NEtWorK FrACturE tHE WALL
04 For the simulation itself, create a DOP (Dynamic 05See how to set up the fracture SOP at 00:52:00.
OPerator) network by selecting DOP Network from the To define which part of the wall to shatter, create a Point
Tab menu (shows as AutoDopNetwork in the Network VOP using a Turbulent Noise node connected via a Float
Editor). At 00:51:40 in the video, you can see the network to Vector node to the Color channel of a Geometry VOP
structure you're going to recreate. The next step is to Output Variables node. When connected to a Scatter
create a Voronoi Fracture SOP to shatter the geometry, SOP, it fractures the wall only in the red areas for a
using the output of the wall SOP as its starting point. realistically random-looking fracture.

3D WorlD October 2017 60 www.youtube.com/3dworld