Rendering corruptions

[hdace]

I've switched to a more powerful computer. It's MacOS 10.12.6, Xeon 8 core cpu, 64GB RAM, & 2 Titan Black GPU's. IPR is usually, BUT NOT ALWAYS, working now albeit with the moving mouse issue and when it doesn't work I have to force quit.

But rendering this panorama is highly problematic. It renders fine with LW native renderer. It's supposed to have grass which is why I'm not too bothered with the somewhat unrealistic ground. When the grass is there it looks fine. Here is a list of problems and I'm also uploading some images.

Trees render okay unless they’re cloned. Shadows look good but trees are corrupted or even invisible. Trees’ alpha channels have weird holes.

Adding displacement to terrain adds white splotches and alpha channel holes. Adding displacement to river has same alpha channel holes and also randomly blackens.

FiberFX renders far fewer blades of grass than LW native renderer.

Thanks for any advice --Hal

all the trees in the foreground are native LW clones

it's easier to see the corruptions in clay mode. trees don't render at all, or partially render, but oddly the shadows are all there

this shows landscape with no displacement to the landscape

this shows with displacement turned on to the three surfaces, two ground, one river. the white splotches are also where the alpha channel holes are

[hdace]

Maybe problems are caused by geometry intersection?

[hdace]

I've now discovered that the tree clones are not rendering at all, not even part of them. I was seeing alpha channel holes.

[juanjgon]

The problem can be the huge scene scale, or perhaps a scene that is not centered in the origin. Have you tried to increase the kernel ray epsilon parameter to see if it helps? If not, if you want to send me the scene I could take a look at it.

Thanks,
-Juanjo

[hdace]

Thanks, Juanjo

I've tried playing with ray epsilon but it doesn't help very much.

Here is a link to my adobe assets folder with this scene in it:
https://adobe.ly/2TEDbm4

If you have a look I'd be pleased to hear your opinion. As of now I don't see how I can render this scene in Octane so I guess I have to go native again.

Thanks again, Hal

[juanjgon]

Can you please compress all the files into a single .rar file? I don't know how to download all these assets using a single click!

One thing that you could try is to disable the "instance LW clones" option in the render target root node options panel, but I'm not sure if your problem could be related to this option ...

Thanks,
-Juanjo

[hdace]

Okay there's a zip file there now. Macs don't do rar, sorry

[juanjgon]

Hmm ... to be honest, I'm not sure why this scene has these kinds of problems, but I'm afraid that the main issue here can be the huge scene scale that you are trying to render. Your terrain has 40x40 Km ... at that scale trying to render detailed objects like trees or grass with the camera set several Km far away from the scene origin can be really hard for Octane working using single precision maths.

You huge epsilon parameter is not going to help either. If you want to render tree leaves or grass, the value is going to need to be set to 1 mm or less, but with this epsilon, the 40x40 Km terrain is going to be broken for sure.

I've checked the objects, and themselves in a clean scene work fine. Have you tried to build a scene like that with these objects in a smaller terrain to see if at least the scene scale could be the source of the problem?

Thanks,
-Juanjo

[hdace]

Juanjo,

Yes the trees render fine on a small scale.

I can't make the scene scale smaller because the camera is doing a full 360º pan and needs to see the hills on the horizon as well as those somewhat closer. And it's not just one shot. I'm doing several in different locations in the same model. It's a model of Manhattan, Kansas and it's geographically accurate. There are dissolves in and out of the pans from live action drone footage to the animation.

So there's just no way Octane can handle it.

I remember now having similar problems a couple of years ago. I frequently do big scale scenes so I'm going to have to get better at using the native renderer until Octane goes to a floating point precision math system, if that ever happens. Which would please me very much, needless to say.

Thanks very much, Hal