Hi all,

I am having trouble getting vats to work with substrate. Substrate doesn't support the custom uv channels required by the vats functions. Any help is appreciated to get these working.

thanks

I have a fluid vat with unpacked normals (separate normal map) emitting from a Niagara particle system. It all works fine, but once the particle rotates, the normals on the vat do not update. Any ideas on how to fix this? I tried transforming the normal from particle mesh space to world space, but that didn't help either.

thanks

I posted this in another thread but hoped it would get traction in it's own thread. This is using the Engine plugin from this link: https://github.com/sideeffects/HoudiniEngineForUnreal-v2/releases/tag/v2.0.3 [github.com]

Most hdas work as expected with the new build that was posted to github, but once an hda has a ramp parameter on it, it crashes Unreal. It doesn't matter the type of ramp, spline or color, they both crash Unreal. This was working in earlier versions of the plugin. So a lot of the hdas we've created aren't currently working unfortunately. Hopefully it is an easy fix?

I've attached a simple hda to test with and without the ramp. I can get it to crash consistently using this hda or by removing the ramp from the interface it works fine with no crashes. Also below is the crash log from Unreal.

thanks for the help

-----------------------------
Crash log:

Assertion failed: (Index >= 0) & (Index < ArrayNum) Array index out of bounds: -1 from an array of size 7

UE4Editor_Core!AssertFailedImplV()
UE4Editor_Core!FDebug::CheckVerifyFailedImpl()
UE4Editor_HoudiniEngineEditor!DispatchCheckVerify<void,<lambda_d081a37e3b4b82b66229d44c87df2878> >()
UE4Editor_HoudiniEngineEditor!FHoudiniParameterDetails::CreateWidgetRampPoints()
UE4Editor_HoudiniEngineEditor!FHoudiniParameterDetails::CreateWidgetFloatRamp()
UE4Editor_HoudiniEngineEditor!FHoudiniParameterDetails::CreateWidget()
UE4Editor_HoudiniEngineEditor!FHoudiniAssetComponentDetails::CustomizeDetails()
UE4Editor_PropertyEditor!DetailLayoutHelpers::QueryCustomDetailLayout()
UE4Editor_PropertyEditor!SDetailsViewBase::UpdateSinglePropertyMap()
UE4Editor_PropertyEditor!SDetailsViewBase::UpdatePropertyMaps()
UE4Editor_PropertyEditor!SDetailsView::PostSetObject()
UE4Editor_PropertyEditor!SDetailsView::SetObjectArrayPrivate()
UE4Editor_PropertyEditor!SDetailsView::SetObjects()
UE4Editor_PropertyEditor!FPropertyEditorModule::UpdatePropertyViews()
UE4Editor_HoudiniEngine!FHoudiniEngineUtils::UpdateEditorProperties_Internal()
UE4Editor_HoudiniEngine!FHoudiniEngineUtils::UpdateEditorProperties()
UE4Editor_HoudiniEngine!FHoudiniParameterTranslator::UpdateLoadedParameters()
UE4Editor_HoudiniEngine!FHoudiniEngineManager::ProcessComponent()
UE4Editor_HoudiniEngine!FHoudiniEngineManager::Tick()
UE4Editor_Core!FTicker::Tick()
UE4Editor!FEngineLoop::Tick()
UE4Editor!GuardedMain()
UE4Editor!GuardedMainWrapper()
UE4Editor!WinMain()
UE4Editor!__scrt_common_main_seh()
kernel32
ntdll

dperuit,

Through a lot of trial and error I've narrowed down the issue. Most hdas work as expected with the new build that you posted to github, but once an hda has a ramp parameter on it, it crashes Unreal. It doesn't matter the type of ramp, spline or color, they both crash Unreal. This was working in earlier versions of the plugin. So a lot of the hdas we've created aren't currently working unfortunately. Hopefully it is an easy fix?

I've attached a simple hda to test with and without the ramp. I can get it to crash consistently using this hda or by removing the ramp from the interface it works fine with no crashes. Also below is the crash log from Unreal.

thanks for the help

-----------------------------
Crash log:

Assertion failed: (Index >= 0) & (Index < ArrayNum) Array index out of bounds: -1 from an array of size 7

UE4Editor_Core!AssertFailedImplV()
UE4Editor_Core!FDebug::CheckVerifyFailedImpl()
UE4Editor_HoudiniEngineEditor!DispatchCheckVerify<void,<lambda_d081a37e3b4b82b66229d44c87df2878> >()
UE4Editor_HoudiniEngineEditor!FHoudiniParameterDetails::CreateWidgetRampPoints()
UE4Editor_HoudiniEngineEditor!FHoudiniParameterDetails::CreateWidgetFloatRamp()
UE4Editor_HoudiniEngineEditor!FHoudiniParameterDetails::CreateWidget()
UE4Editor_HoudiniEngineEditor!FHoudiniAssetComponentDetails::CustomizeDetails()
UE4Editor_PropertyEditor!DetailLayoutHelpers::QueryCustomDetailLayout()
UE4Editor_PropertyEditor!SDetailsViewBase::UpdateSinglePropertyMap()
UE4Editor_PropertyEditor!SDetailsViewBase::UpdatePropertyMaps()
UE4Editor_PropertyEditor!SDetailsView::PostSetObject()
UE4Editor_PropertyEditor!SDetailsView::SetObjectArrayPrivate()
UE4Editor_PropertyEditor!SDetailsView::SetObjects()
UE4Editor_PropertyEditor!FPropertyEditorModule::UpdatePropertyViews()
UE4Editor_HoudiniEngine!FHoudiniEngineUtils::UpdateEditorProperties_Internal()
UE4Editor_HoudiniEngine!FHoudiniEngineUtils::UpdateEditorProperties()
UE4Editor_HoudiniEngine!FHoudiniParameterTranslator::UpdateLoadedParameters()
UE4Editor_HoudiniEngine!FHoudiniEngineManager::ProcessComponent()
UE4Editor_HoudiniEngine!FHoudiniEngineManager::Tick()
UE4Editor_Core!FTicker::Tick()
UE4Editor!FEngineLoop::Tick()
UE4Editor!GuardedMain()
UE4Editor!GuardedMainWrapper()
UE4Editor!WinMain()
UE4Editor!__scrt_common_main_seh()
kernel32
ntdll

Any updates on this?

thanks for the help

dpernuit
Hi,

Thanks for bringing this up, it seems like the 4.26 files were not updated properly on github (the other UE versions of that update were fine). Both the source files on the Houdini18.5-4.26 branch and the release zip for 4.26 weren't updated properly and used an older version of the plugin.

I just fixed that, the 4.26 release binaries available here:
https://github.com/sideeffects/HoudiniEngineForUnreal-v2/releases/tag/v2.0.3 [github.com]

are now the proper 633 version, and I just push the update to the source code as well.

Using that version should fix your issues.

Hey, thanks for updating it. I downloaded it and installed it and confirmed that the uplugin file now does indeed say 633. Unfortunately, the hdas are still crashing the project. It looks like any hdas that were built earlier than 633 are working fine, but anything, at least on my end, done in 633 is crashing with this version of the plugin. Any ideas? Thanks!

dpernuit
Hi,

Yes, that is a known issue that was introduced in 18.5.633, and fixed in 634.

You can either switch to a daily build, or use the plugin binaries on github.
They are linked to H18.5.633 but have the fix.

https://github.com/sideeffects/HoudiniEngineForUnreal-v2/releases/tag/v2.0.3 [github.com]

Hey Dpernuit,

We tried downloading the HoudiniEngine-v2.0.3-H18.5.633-UE4.26 file from the github link and installed it in the project, but now my hdas that were built with 633 crash the project.

On further investigation, on of our engineers mentioned that the HoudiniEngine.uplugin file in the zip is version 408.

what are your thoughts? thanks for the help!

I am also having this same issue. Any help is appreciated!

Does anyone know if it is possible to author a curve with houdini engine and have UE Niagara be able to read that curve in as a spline in order to do things like in a Module Script use the node "Sample Spline Position by Unit Distance WS". Basically, I want to author a curve with HoudiniEngine and be able to have Niagara particles flow along it or start at random locations along the U coord of the spline.

any help is appreciated!

Sure, here you go. Hopefully it is just something I'm missing…

You can see the misshapen polys in the attached images, this is 2000 polys and target polycount=2000.

Hi Mike,

In this example, the mesh shouldn't be changed, yet it is. The incoming mesh has 2000 prims and I've set the vat rop to target polycount=2000. If I look inside objects/TEXTURE/polyreduce_make_sure_the_point_count_is_consistent, the polyreduce isn't doing anything to the mesh and everything looks correct. But, if I look in /objects/debug/ at the reassembled mesh, it is put back together incorrectly with the polys misshapen. In this case, should it be reassembled back as is since the polyreduce isn't doing anything to it?

I see, yes, I was looking at the wrong area for the polyreduce. But, if I look in the vat rop under /objects/debug/ isn't that showing the reassembling of the mesh with the newly generated cloud of triangles? That looks incorrect and the colors are in the wrong place.

I am thinking, maybe it isn't a problem with the polyreduce, but the reassembling of the mesh? I also might be missing something.

Hi Mike, thanks for replying.

I have 2000 prims consistantly (this is just a test sphere) and I've set the target prim count to 10000 on the vat rop but it is still producing the reduced/retopo'd poly mesh. Are you sure it bypasses the reduce? Which, in the fluid portion of the vat rop isn't a polyreduce, but a setup that ends up copying a 3 division circle to the points. Btw, I am using the Labs Vat rop in h18.0.287

Also, It would be great to control this polyreduce because this will eventually go onto a changing fluid surface. I'll need to paint the color and it is hard to know exactly where I painting if it is going to do a reduce when going into the vat rop. I guess if the above method works, I can control it by doing my own reduce then painting after, but I don't think the above method is working.

-Jason

I am exporting a fluid vat with color on it that I am planning on using in the shader, but I am running into an issue that is caused by the polyreduction that in happening within the vat rop. See the attached images, for this test, I am specifically painting an area of this mesh, but once it goes through the vat rop the color gets messed up. Also, my mesh is only 2000 prims, so there is no need for the vat rop to do a polyreduce or a remesh.

For times like these, I think it would be nice to turn off the internal remeshing in the vat rop.

Any ideas on how to turn it off currently?

thanks

Hi,

Has anyone been able to get either the Simple Baker or the Maps Baker to write out multiple frames? In the Simple Baker, I tried setting the ropnet inside to multiple frames, but it just wrote out the first frame for all the frames.

In the Maps Baker, inside the cops_baking, I set the Rop_File_Output for rop_color to write out multiple frames, but the frames it rendered out past the first frame were all in the wrong space on the mesh. If I write out each frame individually, it is correct though.

Not sure what needs to be done to get multiple frames out, any help is appreciated.

thanks

Has anyone had luck with attaching pieces of vellum cloth to a set of incoming particles? I'd like to take a pop sim that is cached out and attach the general motion of the vellum pieces to the pop sim while getting all the fluttering that would happen with vellum. I'd basically like a piece of cloth for each particle and for them to follow the general motion of the attached particle.

thanks,

Hi Mike,

Sorry, I've been out of town, just now got back to this. I downloaded the new update at github and the particle export now works really well. Thanks for fixing that up, really appreciate it.

-Jason

Hey Mike,

Thanks for updating that. Unfortunately, when I download it, the new ROP is empty. Looking into it further, it looks like the Contents.mime file is empty and 0 bytes. Maybe it didn't get posted correctly?

Thanks again,
-Jason

Great, that got it going for the fluid. I had a feeling it was something I was missing. Thank you! So, it seems that there is a polycount limit for bringing meshes into unity? If I raise the detail of the mesh so that the polycount and point count is over 10000, it still causes the same flickering. At least the 5000 count works for now.

Also, did you get a chance to check out the particle sprite in the file? I cannot seem to get that one to work either.

thanks,
Jason