I'm having virtually the same problem as an earlier user – I tried following the quickstart step by step (albeit with the soft vertex shader instead of rigid), but after applying the material, and then pointing the material to the shader, I'm left with the same mesh with no animation, and a pink texture to boot. I've checked my export ROP and the exported mesh seems all right; I don't know how to check the material function though. I'm a fairly new unity user, so I've only really been able to follow the tutorial step by step. I did have to manually install the LWRP to get things to function though, so that was a bit unexpected, but other than that I haven't poked around too much. Any advice?

Using Unity 2019.3.3f1 and the latest Gamedev tools.

cmulliken
and a pink texture to boot.

This makes me think that even though you've installed the LWRP it might not be activated for the project. If you create a default Unity shader graph and assign that to a mesh does it show as pink? If so, the LWRP hasn't been assigned as the renderer for your project.

Yep, that was it! A little confusion over nomenclature since it's been rolled into the Universal pipeline I guess, but assigning the renderer got it to work.

Now I'm having a little issue where my soft deforming geometry is moving in some unexpected ways despite following all of the settings in question–almost looks like a scale or transform issue. Not exactly sure what's wrong with it–is there a list of required attributes for a given vertex animation method? Should I go digging for VAT 1.0 documentation? I'm using the soft constant topology method, as I've made a little procedural unrolling logarithmic spiral that I've extruded into a yoga mat-like thing, and all I have on it is @P, vertex normals and UVs. The Y and the X are nice and stable, but the Z moves way too far across the Z axis in regular, logarithmic intervals, and I have no idea what's wrong with it.

I tried adding an @rest just now, first for the beginning post and second for the ending pose in hopes that that would fix it, but apparently not.

Ah. That could be the other issue which is the colorspace of your project. I think it needs to be set to linear and the default is gamma or sRGB. I forget the exact name but you can find it in your render project settings. If you can, you might want to create a Unity project from scratch with it set to LWRP.

I'll update the shaders to work with the URP in the next couple weeks. If you search the forums, I think I posted the manual changes needed to make the shaders work with URP.

Yep, that fixed it! Thanks for all your help Mike, big props for your responsiveness here.

I have one more question–this time about animation best practices. I saw in another thread that you'd mentioned a time parameter exposed in the material function, is this the same as the speed parameter available via the material, or is there something else I'm missing? Like the other guy, I'm trying to get the animation to play on a trigger, basically, and I'm wondering if I should go forward in trying to figure out how VTA plays with the frame update and finagle something with an animated speed parameter / switching between meshes, or if there's an easier way.

You’ll have to dive into the shader code. There’s a line that’s commented out which uses a different attribute to drive time.

I haven't been able to successfully go through the 2.0 walkthrough video and get the correct results. I get both inconsistent results in both the VAT Rop debug view as well as going through the steps in Unreal. I have walked through the tutorial a few times to make sure I am doing it correctly, but I still can't seem to get it working.

I would expect at least my VAT Rop debug to look correct since there are just a few steps. I am sourcing a sop straight out of the RBD Bullet Solver sop, and has my Method to Rigid.

I uploaded pictures of my RBD sim, what the VAT Rop debug looks like, as well as the view in Unreal. I can upload some more of my files but I wanted to see if there was something right off the bat to check without having to start doing all of that.

I am in Houdini 18.0.348 using Labs release 410 (348) does not work either, and I am in Unreal 4.24.3.

On the rbd bullet solver sop on the advanced or output tab you need to add orient, pivot and rest. If I remember correctly those attributes are cleared inside the rbd solver sop.

Thanks for the assistance Mike. While it seemed to help a little, I was getting all of my chunks clumped together at each of their centroid's positions, something which was fixed by packing them up before sending them to the VAT. Unfortunately in my scene with the geometry I have, whenever I try to debug the output with the pieces packed the scene crashes. I uploaded my scene as well as with my fractured RBD geometry if you wanted to take a peek at it.

Ah. The unpacking is causing the issue. Drop down a configure after the unpack.

The result will still look wrong in the debug view because of an issue that I created recently when adding a switch to deal with uv2. Even though it looks wrong in the debug view, it should work correctly in UE4. I'll make a change and submit it later today so the debug view looks correct. It'll be available in tomorrow's daily build of the Labs tools.

Mike,
Thanks so much for this great tool and tutorial.
I am testing out the Soft (deforming objects) option in UE4 with a simple test file, a bouncing sphere.

I went through the whole process, and the translation to UE4 is not working right. Here is the animation in Houdini followed by the results in Unreal Engine:




Looking at the Debug node provided in Houdini, it looks different (more correct) than what I see in UE4. I have tried combing through the tutorial, my guess is there's a disconnect with the way that I'm hooking up the texture object to my material function. There's a Normal Map and Color Map input that affects the customized UVs, but I'm not certain if that's necessary or not.



What could I be missing that causes the object to tear apart in UE4?

Thanks,
Seth

Hey Seth. So let's check the basics. Have you set the texture compression correctly? Are the material instance values set correctly?
When you say it looks more right in the debug view, what does that look like?

Thanks for such a quick reply!
The texture compression is set to VectorDisplacementmap, and the instance values are set to the following in the UE4 material instance:
numframes: 25
positionmin: -10
positionmax: 246.4487

Those are the only values I get from the VAT node (where my method is set to Soft). Are there any others I should be setting? The Rigid method gives more.

In the debug, the sphere is skewing off in a diagonal direction instead of up and down. But if I can even reproduce that in UE4, I feel that I'll be a ways further on the right path.

Also, I have UVs on the sphere, a simple Polar mapping.

Can you upload the file? I'll take a look.

Sure thing, here it is attached. Thank you again.

Seth, what type of license are you using?

Houdini Education

Does that make a difference?

Hi Mike,
Is there a way to use these assets with any sort of rotation and retain correct shading? With the normals being in world space the shading gets messed up as soon as you add rotation. I tried transforming them into tangent space but didn't have much luck. Am I missing something obvious?

Hey Matt. The latest material function should have logic to deal with rotations. It's in the upper right corner of the nodes.

Seth, I'll get to your file again tomorrow.