Cubemape camera projection problem

[CBAS VISUAL]

Hi Team,

Yesterday we rendered a VR and when we uploaded in the viewer we have noticed a stitching problem.

Screenshot is from TheViewer website. We tried on another vr viewer and same result.
We've already contact we TheViewer team, and they told us that the little seams are caused by the denoising, but our mainly worry is concerned to the huge gap between the bottom and top projection, as you can see in the image below.


Vr resolution : 6000x1000


Full-speed non-debug version
Build timestamp: Jul  2 2019 18:43:53
Version: 4 hotfix 1 (core 4 (Hotfix 1))
Cinema version: R19.068 CINEMA 4D Studio (single-license)
Plugin status: Plugin successfully loaded

[Piotr theViewer]

Hey Guys

Here is Piotr from theViewer :)

If you use VRay we know that switching off denoiser solves the problem :
https://forums.chaosgroup.com/forum/v-ray-for-3ds-max-forums/v-ray-for-3ds-max-general/70448-subpixel-mapping-and-denoiser-for-vr

But we are not sure what option should we use or shouldn't use with Corona?

@Tom - please help :)

[TomG]

I would avoid using the AI denoisers, they probably wouldn't "understand" this image, but the Corona Denoiser should work.

As for the gap, what image resolution were you using? It would have to be 12:1 (12 times as wide as it is tall), was that the case?

EDIT ah you mentioned 6:1 - is it non-stereo in that case? Would seem odd to use a VR delivery and for it to be mono :)

[CBAS VISUAL]

Can you guys do a VR try with a 6:1 ratio ?

[TomG]

I don't have any VR viewing application set up at the moment to test anything - and that would be a mono VR image, right? Because Corona would need the 12:1 ratio to render a correct stereo cubemap image, it's the only ratio that will work for stereo (so I am not sure what we would be testing with a 6:1 image)

[CBAS VISUAL]

Yes it's a mono VR image.

Can you render a VR and send me the image to test in theViewer app ?

We have always made VR 6: 1 without any problem, that's why I'm surprised it does not work anymore on hotfix1.

[TomG]

Still doing some tests here, but it does look like there is a disconnect between the "ceiling" image and the "walls" (of the cube) - tested this just by cutting and pasting the sections of a mono 6:1 around. Now testing a stereo 12:1 to see what happens there.

You mentioned that this "worked before" - can you let me know what version it worked in, so I can install and test that? Cheers!

[TomG]

And it seems like stereo cubemaps are fine, so the next question would be, which version did monocubemaps work fine in, so we can see what might have changed :)

[TomG]

Actually, with a bit of checking in the cutting and pasting of the image, the mono cubemap actually seems fine. So far have been testing in Max, will check into C4D next - still interested in what version used to work fine for you.

[TomG]

Hi! Apologies for the delay, so my testing shows the following:

- I can't replicate the "broken" alignment between faces that you are showing here. Using cut and paste in Photoshop, everything looks fine and lines up as expected.

- I have noticed that the new High Quality Filtering should be disabled, as it will filter across the "faces" of the cube, causing color bleed from one projection into another. So be sure to use the old filtering when doing cube maps

- Probably best to leave denoising off. In C4D at least, with a very high level of denoising (set to 1, and I didn't run it for that many passes), it did lead to some unwanted effects. So either more passes and much lower denoising blend, or just no denoising, may be the way to go. I will try and test some more there.

- Attaching a cubemap render from C4D, using the free scene from Slashcube. Also attaching the "cut and paste" version where you can see it matches up with no seams.

- I didn't find any problems between using a mono cubemap and stereo (6:1 for mono, 12:1 for stereo)