Tutorial: Stereoscopic panorama with Corona + Cardboard

[TomG]

Does depend on your target audience. For general public consumption, I think 4K would be fine. For anything professional, I would recommend 8K - I can see the difference, and when every drop of quality and professionalism counts, 8K would be the way to go.

So, doing something for fun, 4K is more than enough. For impressing an architectural firm, or a manufacturer, or their clients, I'd say 8K is the way to go. While 4K won't make anyone go "Oh this isn't very good", when compared there is a visible win for the 8K, and you do want that when it comes to some work. Does take longer to render, but does make a visible difference (at least, on things like the GearVR) and gives that extra sharpness and polish! At least, that is my opinion based on my testing so far.

Hope the info helps!

[cecofuli]

I understood very well! Thanks! =)

[FrostKiwi]

I did two renders to test for exactly this. Due to time I had 4k mostly and rerendered 8k to compare.
On cardboard with a 1080 screen, there is zero difference. Even after flipping back and forth for a minute. I think for cardboard 1440p would be the drop off, where 8k may make a small difference. You can opt for 6144² instead.

There obviously is a difference for non cardboard VR.

The big question from me: in lat-long projection we render mostly ceiling and floor, which barely get looked at. The main interest sides get only half the resolution of top and bottom. With cubemap it is equal, so it would be awesome to know the point where quality increase drops off for those.

I recall from a Carmack Keynote, that for GearVR "16k cubemaps" is the optimum. Presuming the length is meant, with stereo rendering on, it is 1333px² per Square.

4k vs 8k attached

[johan belmans]

IMHO not everyone is VR Cardboard ready. Because a few among us have a VR device and most of the smartphones in use don't have a gyro sensor.
So most people will experience 360° panoramas by a web application. With this in mind my VR's have a resolution of 11K.
So if one zoom in on a web app it's still sharp, at least on my 24" monitor.

http://belly.be/Dilsen/tour.html

I used to go for 13K, but it seems Denoiser needs more then 128 GB of RAM without crashing. Reported this issue on Mantis

https://corona-renderer.com/bugs/view.php?id=2011

[cecofuli]

Ok,
this is the final version in 8K.
NL: 4.1 - Rendering Time: 18 hours =)  (i7 970)
I had no free time to play with it more =)
what do you think, TomG?
Do you see the difference with th 4K
In this last version, I had to change a little bit the camera position.
The target and the Camera source weren't exactly on the same hight, before.

Bye!

[JacopoGrosso]

Ok,
this is the final version in 8K.
NL: 4.1 - Rendering Time: 18 hours =)  (i7 970)
I had no free time to play with it more =)
what do you think, TomG?
Do you see the difference with th 4K
In this last version, I had to change a little bit the camera position.
The target and the Camera source weren't exactly on the same hight, before.

Bye!

Wow great! I think it's very realistic! Could I try to use your pano as a HDRI? Obviously with your permission. Because I was thinking to create artificial environments for HDRI illumination :)

[TomG]

Thanks for sharing the images!

Yep, on the GearVR with an S7, there is a noticeable difference in clarity between 4K and 8K with both SairesArt's and cecofuli's images.

For example, in SairesArt's images, the radiator is a good example - the grille on top is sharp and clear in the 8K, but loses detail in the 4K. This can be seen in the 4K image, crop attached - the more distant part of the radiator loses the distinction between the grille elements, and of course that is what you see in VR too. Could be the extra detail in the 8K is lost in Cardboard and ends up just as blurry, depending on the phone and viewer, so that the 8K doesn't look any sharper even though the source image has extra detail; but it is noticeable in CoronaVR on the equipment noted.

That extra sharpness really does add to the experience!

[cecofuli]

In attachment, the rendering with different Eyes separation.
Only 2K and 45 minutes or rendering, but the quality wasn't the purpose of this test.
I think that you can see clearly the differences.

(*) If you have a closer objects, it's better to have Eyes separation: max 15cm. Otherwise you have a problems with nausea.
(*) If you have a big room, like in this scene, you can use ,  Eyes separation: from 20cm to 50 cm. The 3D effect will be better, but the room It may seem.. "small".

Enjoy =)

In order:

(*) 2cm
(*) 5cm
(*) 10cm
(*) 20cm
(*) 30cm
(*) 50cm

[Dionysios.TS]

hmmm, I thought the eye separation should be always left at 0,063m

[Ondra]

changing the eye separation is exactly the same as scaling the entire scene in the opposite direction. Using half separation value means the 3D effect is as if the entire scene was enlarged to 200%. So there is good chance that the scene will appear too small/too large in that case

[cecofuli]

From my previous test, with low eye separation like 63mm, you have a good 3D "sensation", when you are working in a small room.
But, if you work inside a big room, like my factory, the 3D effect isn't so evident, especially for the far walls and red railings.
So, in this situation (like in a stadium), it's better to use >20cm-30.
But, as Ondra already said, the entire scene seems a little bit "small".

In my scene, we have both situations: close objects (the three "balconies) and the very far walls.
So, you have to choose a "compromise". For me, 10 cm was ok. Maybe 15... but it created some bad effect for the very close objects.

As you can see, with 20cm we have some overlapping on the two balconies, but for far objects, the 3D overlapping is very small.
Viceregal, with 50cm is good for the far walls, you can have a nice 3D vision, but you have the "feeling" the the factory is lime a miniature.
But you have too much overlapping for the balconies and a bad "nausa effect" when you watch the balconies.

[Dionysios.TS]

Thanks for getting back guys! :)

Dionysios -

[cecofuli]

Eye offset.
Honestly, I don't see any differences in the stereoscopic perception with my 3D glasses.
Just a distortion on close objects =)



In short, Offset "stretches" the lower and the top part of the spherical rendering, by using the view horizontal line as a symmetry axis.

[Dionysios.TS]

Great examples! Thanks!

And what about the Converge eyes options?.

Dionysios -

[cecofuli]

Give me some minutes =)