Official Labs Vertex Animation Textures 3.0 FAQs and Links

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I am seeing issues with all the varieties of the VAT shaders/examples in Unity 2021.2.10f1 URP. I am not seeing any shader issues either.

The RBD example is displaying exactly as shown in the previous post.
The particle example has no alpha
The soft example is rendering flat as if its occurring scaled on the Y
The Fluid example has some noisy artifacting.

Is there any solution to the shader issues yet?
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i am trying to export vertex animation for particles moving on XZ in 0-1 space. When i increase the point count above 20000 points or so, the VAT ROP node throws an error

"Error rendering child: /out/position/render_position_and_packed_pscale/render_position_and_packed_pscale"

everything gets exported correctly below that point count

My sim is cached and i am using the appropriate option inside the rop
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ok a quick fix was to increase my COP resolution limit by a lot. So the texture now gets exported.

Of course the resolution is crazy right now so i was wondering if there is way to split it into multiple exr images of lower resolution?

my final sim has 500k particles, since i haven't messed around with vertex maps before i don't know if the resulting resolution of 1024 x 117360 (1.3 GB) is something normal or do i need to find another workflow
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Hello,

EDIT*** Just tested the example project files given by sidefx and there is indeed something not translating correctly with UE5 and the VAT exporter in Houdini 19, if anyone knows of a solution, or knows the progress on development, please let me know!!***

EDIT**** Also reverting back to H18.5 (making sure to use the correct plugins)and ue4.27, results are still a big mess on import***

Ive been trying for a couple days now to get RBD sims from Houdini 19 to UE5 with the VAT pipeline and it just seems like its not ready for production. Im currently using 19.0.561 and UE5 preview 2. When I directly use the, what looks like, a new imporved material function in UE5, I am faced with an "exploded view" of the geometry in question(see the attached image),



after I place the material shader onto the mesh. I added the number of frames of the animation and set the texture size to match the imported position and rotation textures. When Setting the speed of the playback over 0, I am getting completely different results from what im seeing in houdini. Verticies are scaling wrong, positions are wrong. The only thing that looks right it the initial orientation of the mesh at its rest point, yet, the pieces are not connected..... One thing I did notice is that the scripted actions to setup the textures no longer exists in UE5? Is this correct? I took the Houdini Engine Plugin from Github.

found here: https://github.com/sideeffects/HoudiniEngineForUnreal/tree/Houdini19.0-Unreal5.00 [github.com]

Im very new to Houdini, but feel like i can manage to follow instructions. Ive packed my primitives, Ive tried to transofrm my pieces to the original fracture state after the simulation. It seems like this should be pretty stright forward...

Especially since ive followed this tutorial at least 5 times with no luck: https://www.youtube.com/watch?v=1cPRYwF-Tvg [www.youtube.com]


Am i looking in the wrong place??

Any insight here would be super useful.

Thanks for your time.
Edited by stevfun - March 26, 2022 05:20:33

Attachments:
VAT error.png (4.3 MB)

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stevfun
Hello,

Ive been trying for a couple days now to get RBD sims from Houdini 19 to UE5 with the VAT pipeline and it just seems like its not ready for production. Im currently using 19.0.561 and UE5 preview 2. When I directly use the, what looks like, a new imporved material function in UE5, I am faced with an "exploded view" of the geometry in question(see the attached image)

I assume you are using the material functions from the HEngine Plugins, try using the MFs from the Labs Plugins instead. This should also bring back the scripted actions. To find the plugin, go to the Real-Time Shaders tab in the VAT Exporter and hit the button "Unreal Engine Content Plugin and Guides". My RBD export looks as expected when using the MF_VAT_RigidBodyDynamics. Unfortunately, exported meshes using the dynamic remeshing method are broken in UE5 preview2. The same asset works fine in UE 4.27
Edited by SparklingHein - April 5, 2022 03:33:46
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Guys, how we can blend two or more vertex animations from Houdini VAT in Unreal?
In my case I need randomly switch several idle animations and blend them on character.
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Is there a hlsl shader example which reads a sideFX Labs VAT anywhere?

(I tried outputting a unity .shader from one of the older implementations of VAT but never got it to generate a file.)

A 'generic' non-engine specific example of a vat vertex shader would be great for situations with custom pipelines or odd use cases.

Cheers and as always great work Labs team, your tools are amazing!
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I updated to
official UE5 release
Houdini 19.0.588
sideFXLabs 19.0.588

and exported my animation again as Dynamic Remeshing VAT with the same result: triangle soup in UE5.
The same asset imported to 4.27.2 using correlating labs package works like a charm.

I know, everyone is excited about using UE5 with HEngine at the moment and I guess this has priority at sideFX, I am just wondering if this bug is known and will be fixed in the future.

A month ago I made the same test, also with the provided assets from the tutorial "VERTEX ANIMATION TEXTURES IN UNREAL", and got the same result. I am pretty sure I did everything right, one thing I noticed is, that the Labs Plugin that came with 19.0.588 is in a folder named 5.0EA. Is this even the dedicated version?
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Hi guys !
Im working on a Vellum Cloth sim of a feather with a lot of hairs who are supposed to float in the wind. Is there a tutorial or some info about how to use the VAT Rop for the three js framework ? I just see the unreal and unity export options and the custom one and dont know which one i should use to correctly get the desired maps.
Any help is appreciated
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Hi all..

so I have a small issue when having exported the FBX from Houdini. It basically works but I always get these nasty small kind of min max triangles in the exported FBX. Is there a simple way to switch these off and disable them exporting with the FBX. I digged through the export nodes and found it seems to be added in the export/export/mesh node ... tried blasting it on the prelast node before OUT_DATA_GEO null node but it seems to break the VAT when importing. Any ideas I could do?

Attachments:
houdinivat.jpg (1.0 MB)

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Hello. Thanks for the VAT toolset!
Is support for Instanced Static Meshes working properly with UE5 and latest VAT3.0 in labs? I can't get it to work - I exported from Houdini with the checkbox enabled and as soon as I enable it also in UE Material - all my mesh normals get wrong (there are splotches in normals as well as general normal direction on instances seem wrong) and also animation is not working and it just stays on first frame. But at least vertex positions seem correct. Without enabling it in material, normals are fine, but when used in ISM or Niagara, all positions are jumbled up.

Any ideas what might be wrong?

EDIT
SOLVED: Found out I need to manually fill the bounds values from exported data file. (Set VAT Material Instance from Data Table command was not working in UE5 for whatever reason, so I did it manually).

I think this should be mentioned in tooltips so people don't miss it! I found it only through this artstation page: https://www.artstation.com/artwork/zOyke6 [www.artstation.com]

EDIT2 - multiple materials are not working properly:
If your mesh has multiple materials assigned, it seems not to work for other than the first material. That part of the mesh just gets jumbled. I guess that mesh part has different bounds information although I use the same position and rotation texture for all materials and it seems to be working in normal (non-instanced) mode.
Edited by rendereverything - May 10, 2022 16:47:21

Attachments:
vat_instancing_normals_wut.jpg (111.3 KB)
vat_instancing_normals_wut2.jpg (208.6 KB)

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Hi, I'm trying to import a liquid simulation from houdini to Unreal 5 using VAT but my mesh is changing ever time and full of hole?Why?

Attachments:
未命名1653637598.png (390.6 KB)

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WANGHAN
Hi, I'm trying to import a liquid simulation from houdini to Unreal 5 using VAT but my mesh is changing ever time and full of hole?Why?

Please see this update for solution: https://www.sidefx.com/forum/topic/81422/?page=1#post-350761 [www.sidefx.com]
Mai Ao
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Hi!

Thank you so much for putting this together!

I was wondering if the workflow has changed for Unreal Engine 5? Especially for the fluids/dynamic remeshing vat? I'm currently using Houdini 19.0.455 and UE 5.0.2. I did follow all the steps but still don't get a clean mesh.
Image Not Found


The same vat works perfectly on UE 4.27.2 though.
Image Not Found


I'd greatly appreciate your help.

Cheers!

Attachments:
UE_5.0.2_Capture.mp4 (11.4 MB)
UE_4.27_Capture.mp4 (6.0 MB)

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darkPrince
Hi!

I was wondering if the workflow has changed for Unreal Engine 5? Especially for the fluids/dynamic remeshing vat? I'm currently using Houdini 19.0.455 and UE 5.0.2. I did follow all the steps but still don't get a clean mesh.
Image Not Found


The same vat works perfectly on UE 4.27.2 though.

I'd greatly appreciate your help.

Cheers!

No problem

It didn't change. Please make sure you used the 5.0 version of SideFX Labs plugin, not 5.0EA. And the rest was the same. I was testing on some projects just today and it worked fine. Please also check if your textures are compressed correctly using Scripted Asset Actions and try restarting Unreal. More on this: https://www.sidefx.com/forum/topic/81422/#post-350761 [www.sidefx.com]
Mai Ao
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Hello!

I have been trying to wrap my head around the Rigidbody VAT3 Shadergraph for Unity. The Min and Max Bounds has some sort of magic values which makes the simulation work correctly. Changing it slightly breaks the whole simulation. I checked the shadergraph of URP which is quite different than the shader code for standard pipeline.

I followed this tutorial [youtu.be] to create a Rigidbody simulation. Only when I use the values provided in the example project for Bound Min and Max, it seems to work.

I am trying to recreate the shader and have not been able to understand the bound related calculations in the shader.
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SurajShettigar
Hello!

I have been trying to wrap my head around the Rigidbody VAT3 Shadergraph for Unity. The Min and Max Bounds has some sort of magic values which makes the simulation work correctly. Changing it slightly breaks the whole simulation. I checked the shadergraph of URP which is quite different than the shader code for standard pipeline.

I followed this tutorial [youtu.be] to create a Rigidbody simulation. Only when I use the values provided in the example project for Bound Min and Max, it seems to work.

I am trying to recreate the shader and have not been able to understand the bound related calculations in the shader.

Hi! The bounds are not just bounds. They are encoded with additional data that VAT shader needs. That's why you have to use the values exported from VAT node and you can't really modify them. The encoding is slightly complicated, but let me know if you want a full and long explanation.
Mai Ao
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I'm trying to get Rigid Body VAT 3.0 working with Unity 2021.3.2f1.
I installed the URP_VAT3 shaders in Unity.
The rotations don't seem to be working correctly: the 2nd frame in Houdini:

and in Unity:

Looking at the shader - it appears the Decode_Quaternion is displaying magenta - not sure if this is something to do with it.
Edited by spaceapegames - June 23, 2022 10:04:51

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shaderMistake.png (72.5 KB)
UnityFrame2.png (24.2 KB)
houdiniFrame2.png (41.5 KB)

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"vat particle sprites" causes flicker when "mesh render" of "niagara" is written. Is there any solution?

houdini vat in

entered "houdini vat installing -> bound max, min xyz", but flicker occurs
Edited by immeen - July 1, 2022 04:05:16

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KakaoTalk_20220701_165939474.mp4 (756.2 KB)

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Hello! I made an error when exporting Unreal using VAT fluids. lookup export failed. Hope that helps.
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