UE5 & Houdini
Houdini Engine
Install
- Browse to the SideFX houdini engine dir
- SideFX directory
- C:\Program Files\Side Effects Software\Houdini Engine\Unreal
- Here you will find the engine for each of the houdini versions you have installed
- And inside each houdini version you will find a houdini engine plugin for each of the unreal engine versions.
- Copy Houdini Engine dir
- Find the version that matches your Houdini install and the UE engine
- Ctrl + C the HoudiniEngine directory
- Browse to the Unreal plugin dir
- Unreal engine version directory
- C:\Program Files\Epic Games\UE_5.0\Engine\Plugins\Runtime
- Paste the Houdini Engine dir
- Ctrl + V the HoudiniEngine directory we copied in the earlier step
- Note!
- If you have intalled Houdini Engine for this version of unreal engine berfore you will allready have a dir called HoudiniEngine, just delete it and then paste the copied version
Gotcha
Outputs
- Proxy Static Mesh
- With proxy static mesh enabled houdini engine will create a proxy which will be faster to generate
- Might have some artifacts
- You can disable this if here
- Houdini Proxy Mesh Generation >
- Enable Proxy Static Mesh : On/Off
- Multiple Outputs
- In Houdini
- Add multiple output nodes
- Set the Output Index of each output to a unique value
- In Unreal
- With the houdini engine actor selected, open the details panel
- Houdini Engine > Asset Options >
- Use Output Nodes : On
- This will make sure each output is used to generate an actor in UE
Docs
Houdini Niagara
Install
- Download the zipped binary fron
GitHub
- Unzip & copy the HoudiniNiagara folder to the …/Epic Games/UE_5.2/Engine/Plugins/FX folder in Unreal.
Example
- Houdini
- Create a particle/point setup that oyu wish to use in Unreal
- add a Labs Niagra ROP node
- Unreal
- Import cache
- In the contnet browser, drag and drop the .hbjson file we saved from Houdini.
- Add a Niagara System
- In the content browser, make sure that Show Plugin Content is enabled
- Select add New system from selected emitter(s)
- In the dialog that popped up make sure that the Library filter Library only is unchecked.
- In the asset type filtering, click Parent Emitters
- In the Uncategorized section select Houdini Niagare Basic
- click the + icon and then finish.
- Note
- You could also an empty system and then add the Houdini Niagare Basic emitter later.
- Setup the system
- Double click to enter the niagara system
- On the HoudiniNiagaraBasic overview node there are 3 places we need to reference our houdini point cache
- Note
- We can hold ctrl to select multiple attr on the HoudiniNiagaraBasic node and they will populate and be editable in the selection widget on the right hand side.
- Select
- Emitter Update > Spawn Particles from Houdini Point Cache
- Particle Spawn > Sample Spawned Houdini Point Cache
- Particle Update > Sample Houdini Point Cache
In the selection widget expand the three sectins until you see Houdini Niagara entry. Here we will drag and drop our imported point cache
- Set Loop Duration
- We can se how many seconds our cach is by double clicking the houdini point cache.
- The we can hold shift + RMB click on the Max Sample Time
- Then we go back to our niagara system, select the Emitter Update
- In the Selection tab expand Emitter Update > Emitter State > Life Cycle >
- The paste the copied value to the Loop Duration
- Set Lifetime
- Select Particle Spawn on then expand Particle Spawn > Initialize Particle > Point Attributes >
- Set lifetime to 0.1
- since a particle is spawned every frame we do not need this to be longer.
- Particle Attributes
- Select the HoudiniNiagareBasic node’
- in the parameters panel expand Particle Attributes to see which attributes are accessible.
- Lets set the color
- On the HoudiniNiagareBasic click the + icon on the right side of the Partcle Update
- start typing ‘col…’ select General > Color > color
- With the added color module selected we can see that we can edit the color in the selection panel.
- Since the color value is RGBA and the houdini color is a vec3 we need to use the Scale Color (a vec3) to set the color.
- On the right side of the scale color klick the down arrow and start typing ‘hou…’ then select Particles Houdini Color
- Lets set the Size
- we are using a sprite renderer so we will set the sprite size.
- Click the + icon on the right side of the Particle Update
- start typing ‘spr…’ then select Scale Sprite Size
- in the selection panel change the Scale Sprite Size > Scale Sprite Size Mode to Uniform
- Because there is a difference in units we need to multiply the houdini pscale with a large number (lets start with 100) to get the correct size
- Click on the arrow on the right side of Uniform Scale Factor and start typing ‘mul…’ select Multiply by Float.
- Set the A value to 100
- click on the arrow on the right side of B and start typing hou… select Particles Houdini Pscale
- https://youtu.be/GAn1Za1MYW4?t=710