Skybox Cubemap

[Alexia Borson]

Iknow that skybox/cubemap image files are to be the same resolution and square. However, I think some devices are not able to view my skybox/cubemaps because the resolution was to high, and probably the device did not have enough RAM.

I found that 512 is about to be guaranteed to be supported across all platforms.

We probably should have check in engine, that would auto-resize cubemap to supported size if it is too large.

There is a ticket for it:

I started with cubemap images of 2560x2560 but some devices displayed black.

I changed to 1024x1024 and 720x720 both worked with all devices but one.

Ran Webglreport on device and report said browser supports it but it is diabled possibly driver update needed. Now in process of doing several OS updates on the device.

If in fact images are being resized automatically by PLAYCANVAS what would be optimal settings?

Image size uploaded should probably match image size used (or is it scaled for different devices), what is that size? 512x512 1024x1024

So yes, you want to upload PoT textures to preserve best quality.

In this case, JPG will be better, as it will be already large enough, and you want to minimize assets size to allow users enjoy content without need to download too many Mb.

Once upon a time... I collected 38 Elyvision skyboxes, corrected their texture names to be BJS-ready... put bottoms on the skyboxes that didn't have bottoms... and packed-up all 38 with a demo viewer... into THIS zip. _tour.zip

Note: Skyboxes without bottom textures - 5-texture skyboxes... expect the programmer to use a "ground" as the bottom texture. ie. No need for bottom texture when there is a floor/ground in the scene. BUT, BabylonJS cubeMaps need a 6th texture (negativeY/_ny)... so, I had to "make" some.

Yeah! Be patient as you tour with [ and ] keys. Textures take time to load. G-button toggles ground, M-button toggles model, R-button for reset. Skybox1 is possibly a non-Elyvision skybox. Not sure. "Skybox1" is the first skybox used in a BJS scene, EVER, I believe. It is available in our playground, too. I think 3 Elyvision skyboxes are playground-reachable, as well.

@Deltakosh only gets 100 emails a day from adoring female fans? Blimey old chap, you're slacking!!! I get at least 500 a day from Russian women who are apparently desperate to meet up with me ? heck, even some who are distant relatives and can send me a whole heap of cash for a small investment ? haha

This would be a great feature to add along with an artifical sunlight item

Also what software did you use to demonstrate the skybox cube? I thought it looked like hammer but the env_sun icon is different

I followed the SaschaWillems texturecubemap example and I managed to load and create the cubemap image, image layout, image sampler and the image view. But when I finally render it with the skybox.vert and skybox.frag (after compiling them to SPIR-V) the cubemap renders outside the cube object (just like another object). I also used the Cube.obj file included in the repository.

In future we plan to add support for any type of texture for skybox source, so that you could directly use your jpg.

Unfortunately currently only cubemap textures are supported, so you need first to convert your jpg into a cubemap using an external tool.

I am sorry, this is only mine opinion.

I think that full sky simulation with animated or even simulated particle clouds, atmospheric scattering on skydome - this are modern for me. In place of static skybox.

I have some issues changing the skybox at runtime. Actually, the problem is quite complex (at least for me). What I would like to do : the user can load an image (360 image, such as from street view) and the environment change around him (virtual reality application). In my script, I load the image and create a cubemap from it, make a material containing this cubemap and finally set the new skybox material with this one.

I am having some problems with rendering skybox without post-processing effects. I was able to get this setup to work by using two framebuffers and by sharing a single stencil buffer between the framebuffers. The issue with this method is that most of the graphics cards does not seem to support this kind of stencil buffer sharing between the two framebuffers. The more commonly supported technique seems to be by using GL_DEPTH24_STENCIL8 when constructing the framebuffer, but there is no way to share the stencil buffer between the framebuffers when this packed format is being used? I have tried both texture framebuffers and render buffer objects.

Now, is there a way to do this same thing when both normalfb and bloomfb are using the packed format GL_DEPTH24_STENCIL8? At this point I am willing to sacrifice some performance for compability if there is some way to fix this, like:

Cube size is irrelevant, as is the size of the scene you render onto the cube. The trick is to render the cube before everything else in the scene without depth testing or updating, with the cube centred at the camera - that way when the rest of the scene is rendered it will appear in front of the cube map. I just used the search function of this forum to get =3192&highlight=skybox, which has code that looks right in the 4th post. Also, there is a cubemap generation tutorial posted in general discussion right, now which might be of use.

Instead of the 6 faces of a cube, UE4 really wants environment maps inEquirectangular projection,which is an image which is twice as wide as it is high, and encodes the 6 facesof the skybox cube like this:

But what if you have old-style cubemap files like this old man is used to?Unfortunately, UE4 is quite restrictive here, which is what caused me confusion.For one, it seems to have no support at all for combining 6 separate imagesinto a cubemap in the editor itself, the default fallback I would have usually reached for.

This is all fine but you need to render this skybox on something, right?The benefit of generating texture coordinates from the camera is that anygeometry we put this material on will appear to be infinitely far away.

I've been using the Panorama to Cubemap tool to port SpaceEngine skyboxes into CS:GO. To be more specific, I've been converting panoramic/cylindrical screenshots taken in SpaceEngine into the Valve skybox format. For the Cubemap to Panorama tool, I've been using it to apply CS:GO sky textures onto skydomes.

To use the Panorama to Cubemap tool, upload your panoramic screenshot in a 2:1 format. After the tool processes your screenshot, download the cubemaps by clicking on the individual faces. Use the following conversion to rename the cubemap faces:

To use the Cubemap to Panorama tool, upload each cubemap image into each respective slot (upload BK to Back, LF to left etc.) When it comes to rotation, make sure the Up face rotation is set to 90 degrees, while all the other faces are set to 0 degrees. After setting your resolution, you can now download your new panoramic skybox.

Used that first link a bit too a year or some ago to try and get some architectural photos extracted from equirectangular panoramas, it seems like a good first step but if the building is wider or higher than the cube face you just end up with heaps of work trying to fix the bent pieces than if you used a proper panorama editor in the first place

Was a little tough trying to figure out Hugin ((free) panorama editor) because I guess turning panoramas into not-panoramas isn't what panorama creation software is primarily geared towards, and since I guess noone else was doing it either because it was pretty hard to troubleshoot. Well either that or I just lacked the photographers' jargon needed to search my issue.

Hi everyone,

Very interesting, but I've got a cubemap of 5K faces each, how could I do ?

What it the limit size of the final panorama ?

Looks like there is a limit of 6900pixels large ? right ? Looks like cannot go upper...

I am using Unity 5.3.5 and am trying to implement 6 skyboxes in my project. Each skybox is at most 3mb in size but when i build my project, the app size becomes 87mb! I tried looking into details and found that each skybox converted to cubemap has been sized to 16mb(14.2%). This I saw found out from editor.log in

A client wants an existing cleared lot photographed to be used in renderings for an upcoming residential project we're designing for the site. I'm thinking I'll photograph the site from a fixed central point, taking shots while rotating the 360 degrees, keeping about a 20-30% overlap between each shot. One revolution at horizon, then one below and one above, each keeping the same overlap. Stitch the shots into a panoramic using Photoshop. In Sketchup, load the image into Vray Domelight and render a cubemap.

I should note that this will be my very first attempt at producing a equirectangular image, or my own IBL of any type for that matter....(I prefer PG HDRI's.....but unfortunately he isn't available to come shoot the site this week)

There is a cool tutorial on how to make HDR skyboxes from Panorama's using streetview downloader -G47M what you will do will be similiar but instead of starting with the google earth, you will start with your pano. The key I found was using png files, not jpgs, prior to setting the exposures and creating the HDR. Does photoshop stitch the photos together for you or are you using another software to process your photos?

Yes, when i first read that article I somehow missed the fact that you don't necessarily need a 'cross' format skybox, you can use a regular 2:1 panorama. That will be easier to make, just basic Photoshop panorama stitching.

I have normal skybox via CubeMap, but i noticed that the size of the cube has no effect. I would expect that when i have cube size 20.0, i will see different result than with cube of size 1000.0 (same as if you have texture 20x20 on 20x20 face and on 1000x1000 face).

Cube mapping works by sampling a special cube texture (consisting of six 2D textures, one for each face) by normalized 3d vector coordinates. If you get 3D coordinates from a cube scaled by 1000, and normalize those, you get the same coordinates as you would from a unit cube.

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