Are these animation names set in blender? If so, where is the window in blender? I’m looking at the skeleton.blend file for Chapter 8.
Chapter 8 : looking for skeleton.blend file “wave”
Chapter 9 : Is there a way to see the animation for “idle” and “sit” in blender?
When the previous Metal by Tutorials edition came out, all the tools were very new. So I did various animations in multiple 3D apps and then combined them into Chapter 9’s .usda file laboriously copying and pasting text and trying them out to make sure they worked. There is still no .usd import in Blender, and the .usd export is not 100%.
I expect to have to redo the animation with the current tools, but I haven’t revisited animation yet.
3D apps like Maya and Houdini have a much better USD workflow, but of course they cost money.
I don’t have the animations in Blender, but you can do multiple animations and name them there.
- Create a new Blender file with default cube.
- Choose Animation along the top to show the Animation desk top
- Click the “Dope Sheet” dropdown at the top left of the bottom animation panel and choose “Action Editor”
- Click + New
- Name the animation and click the shield to save it
- Click the double pages on the right of the shield for a new animation
- Name the animation and click the shield to save it
- Click the little icon on the left of the name to switch between your animations.
This video on non-linear animation might help too: https://youtu.be/mfdufhaiKtI
This file has a cube with two actions - one animating up and down, and the other sideways. It then combines the actions into one animation.
animations.blend.zip (97.8 KB)
This is the Blender walk:
skeletonAnimatedV4.blend.zip (218.1 KB)
@caroline I have Maya, let me know if I can help
@mk2019 - That’s very kind of you, thank you! I do have a question as to whether Maya is better at USD than Houdini is. (I suspect it’s more my lack of knowledge than Houdini’s ability at this point though.)
I haven’t yet worked out how to do
USDSkel stuff in Houdini. I wish I’d made more notes on how I collated the animations to the .usda at the time, but I was using so many different apps, because fbx never seems to spark joy.
For the book I always try to work out how to do it in Blender, so that people can follow along without having to fork out $$$.
This is the .usda file with multiple animations in it:
skeleton.usda.zip (196.0 KB)
Xcode’s SceneKit editor shows:
The eventual aim is to have a workflow where I have multiple action animations in Blender that I can combine into a usd, and a workflow where I have a usd with skeletal animation that I can turn back into Blender.
But I think I’m ahead of Blender’s roadmap on this.
Does Maya easily import the usda file and show the animations?
@caroline thanks for you fast response. I understand better now. I tried to get usd working in Blender (windows and mac) two years ago without any success.
Is USD better under Houdini? The learning version is free as long as it is for self use.
@kaitlynhwang - Houdini Apprentice (the free one) doesn’t let you export (except for obj). But it’s a fine product to help understanding of procedural geometry. (And what you can do in parallel processing using VEX.)
Solaris (the Houdini USD environment) is good for creating static scenes and variants, but it’s not for animation. I don’t yet understand the USD procedure for skeletal animation in Houdini. The last resort - I will have to examine the documentation.
@caroline Thanks. You saved me some time figuring out Houdini Apprentice
@kaitlynhwang @mk2019 - On the other hand, Apple has sample code with multiple animations using .usdc files in RealityKit: https://developer.apple.com/documentation/realitykit/building_an_immersive_experience_with_realitykit
This app loads a different .usdc file (.usdc is a binary USD format) for each animation instead of having multiple animations in one file. Apple might be having the same multiple animations difficulties that we are .
So perhaps that is the way to go for the moment - give up on trying to put all the animations in the same file, and just load different files for each animation.
One animation per file is quite easy, as you can export the file format from Blender that works best (glTF - glb probably) and then convert each to .usd using RealityConverter.
As a side note, I can’t currently run that sample app on my iPad running iOS 15. But I can look at the usd files in Xcode 13 and check out each file’s animation in the SceneKit editor.
@caroline I remember being so frustrated two years ago. I thought I just needed more time or there was a missing piece I didn’t know to make things work. Glad to know that I wasn’t alone in this.
Hi, sorry for the late reply – so many WWDC videos to watch
I tried to import the skeleton.usda from the attached zip, got only the geometry but no animations.
I also tried Apples usd* files from the RealityKit link above, same thing there just geometry, no animations.
See attached screens from Maya2022 using the USD plugin from Releases · Autodesk/maya-usd · GitHub.
So many videos! Thank you for trying. I think Apple’s animations are transformations and not skeletal animation, so I’m surprised they didn’t work, as they are better supported.
I’m away from my computer for a week, but when I return I’ll download the Maya trial and see if I can make sense with your screenshots.
I suspect that it’s just early teething troubles with USD, and skeletal animation seems to have been tagged on the end. But I’ll give it a shot, as it’s going to be a great format eventually
Just following up on this.
I was able to convert a Blender file with multiple animations to .usdz format:
- Export to .glb (glTF format)
- Import .glb file into Reality Converter
- Export to .usdz from Reality Converter
All my animations were there, and I was able to use them using Chapter 9, The Scene Graph
I did have other miscellaneous geometry problems, but hopefully this points the way after sorting them out.
Blender now imports and exports USD
Does the animation work for you with blender 3.0 ? I tried to export the skeleton.blend file from the book and still have no animation in Xcode. I tried also with Houdini (Houdini can export agents (crowd system) to USD skeleton in solaris) but again it works fine but not with Xcode
I can export basic animation like move or rotate a cube but nothing more …
I maybe got a bit too excited about exporting a bouncing ball .
Animated meshes do export from Blender, but skeletal animation isn’t yet supported.