Vertex Animation Textures

[Saya]

Hi Odforce,

So I have made an animation from this organic looking structure and would like to import it into the Unreal Engine 4.25 . I found out that fbx does not support vertex animation. Apparently animation created in houdini for example with noise is vertex animation. Therefore I had it exported it as an alembic but the file was insanely large ( ~700mb). Other forums about alembic mentions alembic in houdini saves everything. I have tried to exclude anything except from the attributes, P, N and still around the same file save. With this journey I stumbled about VAT. Vertex Animation Textures and couldn't find a fitting tutorial that would cover this SOP with the same setting layout.

The questions are:

1: how do I use VAT to export animations out of houdini and import them into UE4.
2: Are there other ways to export animations and import them into UE4?

Screenshot and file are below

Thanks in advance.

Organic roof growth.hip

Edited August 17, 2021 by Saya
added tags

[Librarian]

@Saya You have wonderful ex on "Houdini FX japan"  site.."VAT sample" with various method's ..I use it for CHOPS and COLORS  on vertex
 

[Saya]

Thanks Libarian for the quick response.

This looks scary haha.

Just a quick thought, by generating these maps ue4 will read them out as where the points need to move too?

I've just searched for houdini fx Japan. All I can find is the hive Japan on the sidefx page with a long video of 5 hours

[Librarian]

houdinifx . jp   /blog/

[Saya]

Hey Librarian,

I've read the articles. I'm flabbergasted by the complexity of the required steps to get an animation from Houdini to UE4. I think I understand the process but would never thought of it myself.

However, article #1: https://houdinifx.jp/blog/頂点座標値と頂点インデックスの画像データ出力/#more-14376
is provided with an example file. If I understand this you can alter this file somewhat and use it for your geometry. It looks doable but I'm not sure if the output would correct. One way to find out so I went to article #2

Article #2: https://houdinifx.jp/blog/labs-vertex-animation-textures-rop-作成したvatファイルをue4で読み込む方法/
Explains the process to create a certain code that should be copy pasted into UE4. With scrolling through the article I notice that the interface from the VAT in the given example is different that mine. I can't find a certain section that will create a code for UE4.
I've set all the drop down menu's to Unreal but Sample Shade Code won't pop up. I also just noticed that the sample shade code section does not show up in the example from the website.

So I'm kind of lost here.

Is this the only pipeline to get vertex animation exported from Houdini to UE4?

 

[Saya]

I found on the side fx forum an article about this. https://www.sidefx.com/forum/topic/74083/?page=3 It mentions the creators are working on some sort of bug for the updated version that i have.

All the articles that I can find are using VAT 2.1. Hope to find a version of that.

update:

I have found the following: " by going to Houdini main menu bar > Windows > Asset Manager > Configuration tab, set Asset Bar: to "Display Menu of All Definitions" or "Display Menu If Multiple Definitions". Then you should conveniently see which version of any node you are using on the top of the parameter interface"

By doing so you can switch from versions.

Edited August 17, 2021 by Saya

[Saya]

So, I have been fiddeling with this geo for some a while but i can't seem to figure out what the requirements are for the VAT.

The geo moves around and the gaps closes and open. So i'd figure VAT considers this as an fluid.

When pushing render. It does give me an error: error rendering child.... render position and packed normal.

I cant figure out what the error was. I've tried with a packed geo and an unpacked