What is the IPR update trigger?

[andrewprousalis]

I have noticed that for some high-geo scenes, despite everything being unchecked in the update menu, there is no way to move a light around without the entire scene reloading in the IPR (at the cost of 30-45 seconds). This obviously makes for an annoying experience. It does not appear to be a consistent problem, as I've had it manifest in multiple scenes but not consistently. Any ideas why this is, and could we possibly add a "lighting-mode" where we can reliably move lights around productively?

[juanjgon]

Hmm, do you have an example scene with this behavior, or does it happen in any complex scene?

Thanks,
-Juanjo

[andrewprousalis]

It seems to happen randomly whenever the polycount gets over a few million. Sometimes it will clear itself up and allow things (objects included) to be dragged around, and then a while later it will revert back to the freezing/reloading behavior.

[andrewprousalis]

One more thing that I've noticed: When clicking on a light to move it around, and it triggering this "high point count reload", if you don't let up on the click and wait out the reload, once it does come back up, you can move the light around interactively. But once you release mouse, it will reload again. Completely unusable IPR when lighting something like 100M particles. @juanjgon Has there been any thought on open-sourcing the Houdini plugin? Many people in the Houdini world are also excellent developers. I wonder if this would help speed up the plugin development and get things more tightly integrated.

[andrewprousalis]

Nearly a year later, checking back in on this one. The IPR still randomly reloads the entire scene on every light move once the poly count gets to some millionish number. I'd like to reiterate that if this is not something otoy is interested in fixing, then please open source the plugin so we can make these fixes ourselves. The lack of updates on these simple quality of life improvements doesn't exactly inspire confidence in us that rely our tools to make a living.

[ricky_otoy]

Hi Andrew, I wasn't aware of this thread sorry.

What lights are you using? There was a bug where most lights didn't update the rendering when moved but should be fixed in the next release.

Do you have a scene to share that reliably produces the issue?

[andrewprousalis]

Here ya go. It's just a high poly sphere with some noise on it, copied to the points on a grid. The more your crank up the grid subdivs, the more spheres get copied and the greater the chances of the reload problem getting tripped. Here, around 15M polys consistently tripped the problem, causing the full scene to freeze and reload every time you grab a light handle.

https://www.dropbox.com/scl/fi/46yp5tsh ... bkgsw&dl=0

[andrewprousalis]

Oh, and it's probably worth mentioning that sometimes this happens with a far lower point counts (around 1M), but the high point count almost always triggers it. Thanks for looking into it!

[andrewprousalis]

One more note here: I just realized if you hold onto the light handle after beginning a drag without releasing while the IPR refreshes, then once it finally refreshes you can can drag the light around interactively until you release it.

[ricky_otoy]

Hi yes, that is less than desirable. We will look into it, thanks!