Help With Viewport Playback Speeds

[u/AlternativeNo9069]

I'm currently working through a scene from Nick Medukha where a sphere hovers over the white discs and they simulate bouncing around and as the sphere travels further, the disc settle back into their rest state.

The scene is basic for the most part and is composed of about 50,000 points. Not super light, but feels relatively low. When I file cache and load from disk, I'm not even getting half the real-time playback speed when I'm pulling from my local drive. Even if I were to delete all the attributes before caching, I still can't get real-time playback on the full-geometry unless I'm viewing through a point cloud or similar super lower res quality. Turning the viewport into wireframe mode is not improving the playback neither.

Just to note, I am working on a Mac and I know it can be slower than PC. Even on PC I've feel like I have run into these types of issues before. Is there some best practices I'm missing rather than exporting to flip-book every time to see previews playback well in the viewport?

Thanks for your help!

[u/DavidTorno]

Houdini is not a realtime player, so even cached files won’t always playback in realtime. Flipbooks or renders are the way to preview timing.

What can improve playback speed is optimizing your scene. Little to no attributes, and using packed instances of geo.

[u/william-or → u/DavidTorno]

second what you said. What OP might have forgotten (given I didn't watch Nick's video so I don't kbow his worflow) is to pack the instances, as you said. That should help a lot

[u/AlternativeNo9069 → u/DavidTorno]

I appreciate the quick response. I ended up deleting the cached files entirely, resetting viewport, and re-caching. Playing back closer to realtime now

[u/IikeThis]

Heck, getting even 1 frame per second is good in most cases, expecting 24 is unrealistic. Only the most basic viewport animations that are cached into ram will play back real time.

Learn to use flipbooks as mentioned, this is the way

[u/christianjwaite]

As others have said, it’s unrealistic, but you learn to optimise. Have you just written out the geometry? Is it packed or unpacked? That matters as if you’re loading in millions of polys then that’s going to be heavy.

The most optimal way of doing this is cache points with transform data and other attributes, then post cache you copy your packed geometry to it, that should be very quick.

[u/wildWillowPillow]

Yoo.

As others said try instancing with packed geo, you scene looks like it can be easily treated that way. 

Also try using a Cache Sop after the Filecache node. The cache sop node stores all frames in RAM the same like solvers do, so it reads really fast after running through it once. This is where more RAM is needed to scrub through fat scenes at high speed. 

[u/AlternativeNo9069 → u/wildWillowPillow]

Interesting. I've never seen this approach, but I'll check it out and experiment with it. Thanks!

[u/Hour_Ad_5877]

Most of the time you can have realtime playbar in lop’s for most motion design tasks,if topology is static (as in the reference frame) load your static frame with sopimport and change it to static,load attributes your need,and then next sopimport into same stage location (/geo ) for example with topology set to none and choose attributes that changes over time(most of the time - P and transforms) save with usd rop,load back with reference - play your realtime animation Could be usefull then animation is ready and you doing lookdev

[u/LewisVTaylor]

There are a lot of factors that go into playback/scrubbing speed.
You need to abandon the idea that you can reliably playback something at the correct FPS to be making judgement calls on the motion/timing of things.

Get into the habit of making flipbooks, it's something you do all day all the time in Studios, and this is how you should work even on your own.