Bifrost and Maya viewport display.

[theo7R7XM]

Hello everybody,

I have a scene with many instances scattered with Bifrost and my viewport FPS is very slow. (even with proxy instances)

I had a solution where I just unchecked LOD Visibility so Bifrost is not visible in viewport but at rendertime yes.

However with the latest arnold version (6.0.4.0), object with LOD visibility off are no more visible at rendertime .

So do you guys have a tips for fast viewport with Bifrost ?  

thanks in advance!

[syracoj]

can you share your scene file please? You'll have to zip it up then post it.

[theo7R7XM]

Sorry for the delay, I attached a test scene to my reply.

It a simple sphere with 500 000 cube scattered on it. My viewport goes down to 10 FPS.

I have no need to see the instances on my viewport, I would like them to show only at render time.

Or maybe an option to only show 5 % in the viewport ?

We are using it in production, and we would like to upgrade to the latest Arnold version. But it would force all the lighting artists to display the Bifrost again (lod visibility not working anymore).

Thanks in advance for any help !

[theo7R7XM]

bumping the post.

I'm still looking for a clean way to show a bifrost scatter only at render time. 

I have a workaround with a pre render / post render mel script but it doesn't feel very clean.

Drawing overrides / bounding box doesn't work.

I wish Arnold didn't fix the trick with the LOD visibility option wich was working great for us until now...

Thanks for any help.

[marcus.nordenstam]

Hi there

There is something coming up that will address this issue rather elegantly.  If you're curious, I would stress the importance of watching the Bifrost Vision Series presentation coming on September 9th.  It's called Lights, Camera FX.  You'll see a solution to this and other upcoming features.

https://www.toolfarm.com/news/autodesk-vision-series-september-9-11-2020/

[syracoj · Accepted solution]

my VP performance isn't too bad ~27fps with your scene.

which version of Maya/Bifrost/Arnold are you using?

one thing I tried was to set preview_geometries on the instance node to use points.

To do this I created a value node of type float3. Then plugged this into a construct_points node after I made the construct_points point_position input a fan-in (right click on the port to do this). Then used the points output of the construct_points node as the input for the preview_geometries fan-in.

With this the VP should only be drawing points. And you should gain a significant VP interaction experience (I got up to 79 fps).

Perhaps this could be a workaround for you in the meantime.

[syracoj · Accepted solution]

Another option may be to use the render_archive_instance node.

[theo7R7XM]

thanks for the answers !

I will watch the presentation for sure.

The construct point method is simple and work pretty good.

The viewport is very fast but the playback is still slowed. 

And I will have a look to switch to the render archive for the next time.

Thks!

[marcus.nordenstam]

Hi there

So now that we have shown the vision presentation, in case you missed it, the upcoming Terminals feature that was previewed by Karen is what I was referring to.  

Terminal nodes will have three geo inputs (Diagnostic, Proxy and Final) and compounds that use a Terminal node will automatically manifest three corresponding flag-buttons.  If you hook up the low-res representation into the proxy input and click on the P flag, then the viewport only shows the low-res (proxy) geo.  If you hook up the high-res, final renderable geo into the final port on the Terminal, then the user can click on the F flag to toggle that.

This way, you can author a single compound that is capable of generating both proxy (low-res) and final (high-res/renderable) geo, and the user of your compound can simply toggle between the two by clicking a button.  

Keep your eyes on the Bifrost beta if you want to get an early taste of this.  It's going to be a game-changer for Bifrost.

Marcus