Speed Tree Let’s Make a Forest Copyright © 2015 – Curt Hill

Speed Tree

Let’s Make a Forest

Copyright © 2015 – Curt Hill


Introduction• This is a third party application for

parametrically generating trees and other foliage

• It is not part of the editor• What is sent with the UDK is a

“lite” version– Fewer and more restricted features– Of course, they want the serious

developed to buy the full version

Adding SpeedTree Actors• The UDK comes with several

SpeedTree generated objects– A banana plant, two banyans and tow

tobacco plants (despite this being a tobacco free campus)

• Some of these have the default material and others are properly materialed


Content Browser


Drug onto Scene


Sized


Commentary• Speed tree items usually start very

small – They always need to be sized

• Sometimes they are properly coated with material– Other times not

• Next is the banana plant• It needs a little work from the

material editorCopyright © 2015 – Curt Hill

Banana with out material


Theory• Instead of generating each of

these my hand, we describe how to generate

• Each of the parameters can then be randomly varied so that two trees are not quite the same– Similar to how it is done in nature

• Algorithmic creation of static mesh actors


Starting• Since it is not part of the editor is

must be started separately• It is part of the tools portion of the

kit• There are two pieces:

– Modeler– Compiler

• We will start with the modeler


Modeler Started


File/New


Process• We right click on the tree parts on

the lower right• We then add items• We change parameters• Select the item and apply materials

– We may need to import the textures• We then add more items to the

item we desire• When done we save


Right Click


Changing Trunks Length


Materials• The various parts of the tree get their materials in different parts

• Trunks and branches get it from Materials/Branches on the left

• Leaves get it from leaves/Geometry and cards– A leaf is like a card before the texture is

applied• The standard textures are .TGA

extension• You may need to add the texture files –

as we see next


Finding a Texture


More• Once the texture is in the program

the drop down for Material/Branches or Leafs/Geometry then shows the possibility

• Next we add main branches (1) and secondary branches (2)

• Finally we add leaves– Before the texture they look like cards– After they look better


First Branches


Second Branches


Leaves as Cards


Leaves Textures


Level of Detail


Level of Detail Values• Values that are set poorly may

freeze UDK• Values used:

– Near 175– Far 300– Billboard start 301– Billboard end 400


Now What?• The modeler is done• Next we move onto the Speed Tree

Compiler• This takes things and makes it UDK

importable• After than UDK needs to import


Compiler Starts


Item Selected


Compiler Dialog


SpeedTree• The compilation and modeling is

now done• Once in the process you should

make several variations• Making many trees is not harder

than making one– Make one in the modeler and save– Change the parameters and save as a

new name• Now we return to UDK


UDK• No using trees until we can see it in

the UDK• Start with Content Browser• Use the Import button at the

bottom• Direct it to the directory where the

Speed Tree Compiler left things– Select everything in the directory

• Name the group that will contain it• The import may take a while


Content Browser Import


Import Dialog


Imported


Problems• If the import freezes for a length of

time go back to the level of detail and adjust

• The first use of a tree will require the use of the material editor– Which you should now know about

• When you play the game you will notice that the trees sway in the wind– This is the force setting in the modeler


Attachment• Even though this thing looks good

in SpeedTree modeler we have to reassemble in the UDK

• We have to create materials then attach to tree


Material Creation• Right click the texture• Select Create New Material

– Then name it• For bark just move the texture and

attach to Diffuse in the Material Editor

• For leaves it is somewhat more complicated


Leaves as Material• Attach the basic texture to Diffuse• Attach the normal texture to

Normal• Combine Alpha of new texture with

basic texture to a Math add block – Attach this to the Opacity


Menu To Create Material


Material


Material Selected


Material Editor


Moved and Attached


SpeedTree Editor


Finally for a Tree• Right click the speed tree block

and choose edit speed tree• Now click materials and drop onto

the various parts of the tree• Once this is done drop and size the

tree from the Content Browser


Wind• We can change the swaying in the

wind in a couple of places• In the Speed Tree Modeler is the

Forces property• In the Speed Tree Editor in UDK is

the wind property


Conclusion• SpeedTree is a specialized

modeling software• This allows us to create trees and

shrubs much more easily than conventional modeling software

• We are now able to populate our levels with trees that are similar but not identical


Documents

Speed Tree Let’s Make a Forest Copyright © 2015 – Curt Hill