Rendering a 360 "skybox"?

cooldude234

Hello all, I've been using Carrara 6 pro for quite some time now but not until recently have I been trying to use it to it's full potential.
Now I've used the spherical camera to render a full 360 image on all axis. But this type of image that is rendered only works on sphere's with spherical mapping.
What I'm trying to do is render the equivalent of a skybox, 6 renderings for each side of the cube that it is mapped onto.
I need this to run in a application of mine and it's way easier for me to render skyboxes (cubes that are box mapped) instead of skydomes (spheres with spherical mapping).

The second thing I need is the depth information, a black and white image where either white is the closest polygon, and black is the furthest, or the other way around (doesn't really matter the order, it's simple enough to invert the colour values).

Are these two things possible? If so how?

WendyLuvsCatz

in Carrara you can just put your spherical image in the background under scene.
for mapping a cube, create a cube in the vertex room and on the uv mapping redo it as spherical
you will need to put the map in shader in the glow channel too.
also untick cast and receive shadows on the vertex cube
the advantage of a big cube is you can move the camera in the scene where as you can only rotate it with a 360 background
the disadvantage is you get image distortion at the apex and nadir of the cube and shadow catch does not work.
a sphere will not distort but your objects float in the middle, I have flattened a spherically mapped vertex sphere's base with some success exported to use in iClone annother program I render in as a panodome but still not perfect.

cooldude234

I'm sorry but my question wasn't referring to how to render a skybox inside Carrara, but render a Carrara scene as a skybox.

EDIT: I can upload images to help explain what I mean if that will help

WendyLuvsCatz

you might be able to convert your equirectangular image using QTVR software like Gardengnome if that is what you are asking
sorry I thought you wanted to map an image onto a cube.

cooldude234

I already know how to make a texture onto a cube, I used to do it manually in code (programmed all the vertices, and texture coordinates and normal's :S ), but since I programmed my .obj parser I can load obj files so I don't do it that way anymore :)

The reason why I wanted to avoid using equirectangular images (or skydomes) is that when mapped to a sphere at the tops and bottoms of the sphere the texture get's stretched and distorted. I need a full 360 degree skybox in my application so I can rotate the camera any direction in realtime and have it look like you inside the pre-rendered scene (like google street view, except this method was invented LONG before street view). Is this QTVR software free? More importantly will it have the distorted/stretch marks previously mentioned?

Also is it possible to get the depth of the scene in Carrara, I need to render the skybox with depth information (so I can do some various graphics programming stuff to it)?

WendyLuvsCatz

http://gardengnomesoftware.com/
the one that converts images is not free

cooldude234

So if I want to render skyboxes, should I be using different software? (I'd prefer to render them in Carrara but that is looking bleek)
So what about the depth information is that also a bust?

PS for some reason the daz forums doesn't let me post immediately, it makes me submit at least 30 - 40 post before it actually goes through

WendyLuvsCatz

maybe someone else can help you
I am just a user and do not have all the answers
I myself would just render each side of the mapped cube if I wanted those images and compile them in an image editor

cooldude234

I've tried that, and the seams of the corners of the image don't match up.
I was all excited that I was going to be able to use Carrara for something useful, but now my hopes are down the drain ):

WendyLuvsCatz

most American users are asleep still, I am in Australian
before you flush your hopes, try some patience
someone might have your answers
or not
if not then okay it is useless if it cannot do eveything you want straight out the box
if you find software that does, please share the link
we would all like an easy button
I myselfe usually need to problem solve to do stuff without the advantage of coding skills
depth information I imagine can be calculated from multiple images from several viewpoints
Carrara must do it to use depth of field
how
I have no idea, as I said, just a user who decided to try answer your questions but woefully inadequate at doing so
sorry I wasted your time.

cooldude234

Well how Opengl rasterizes things, it uses a depth buffer to determine whats in front and whats behind (when it draws polygons it draws to the depth buffer, but only if its value is greater than the pixels already in the depth buffer, so it can appear in front).
Most cases when I need something done I program it myself, but I don't want to program a fully usable raytracing applications with standards like Carrara and have animation with. Software like that takes years to develop, I wan't to get this done in about a week.
By the way I'm in Canada and I'm not asleep ;P

cooldude234

Here is why I don't use skydomes (attached in the picture you see distortion at the base of the sphere).

wetcircuit

cooldude234 said:

I was all excited that I was going to be able to use Carrara for something useful, but now my hopes are down the drain ):

:blank:

Did you try creating 6 cameras each pointing at the 4 cardinal directions (plus Up and Down) with a field of view set to 90°...?

Here is a tutorial that talks about correcting skybox seams in Photoshop:
http://www.blendenzo.com/tutSkyBox.html

And here is a photoshop plugin that can convert Sphericals (called equirectangular) into cube faces:
http://www.flamingpear.com/flexify.html

Design Acrobat

If you have Bryce (it was free for awhile) you can make a skybox for games. There are a few tutorials on youtube for this. Basically rotating camera view 0,90,180,270 for the sides (Front, Left, Right, Back) and then top and bottom views in X (90 and - 90 I think) This gives the isometric view so it can be mapped on a cube.

evilproducer

cooldude234 said:

The second thing I need is the depth information, a black and white image where either white is the closest polygon, and black is the furthest, or the other way around (doesn't really matter the order, it's simple enough to invert the colour values).

Are these two things possible? If so how?

Can't ell you about the sky box, but in Carrara it's pretty easy to render a depth pass, which is what you describe in your second question. You can add all sorts of render passes. Go to the Render Room, and under Multi-Pass, click add and a window will open with a whole bunch of different options. Select the one you want, click OK and it is added to the list.

Here's some screen caps and an example:

WendyLuvsCatz

this is what GardenGnome does watermarked as trial version,
top bottom next page 5 images forum max

WendyLuvsCatz

rest

and a quick join up in MS paint

WendyLuvsCatz

actually I missed, it DOES to the cross type too

cooldude234

holly wetcircuit said:

Did you try creating 6 cameras each pointing at the 4 cardinal directions (plus Up and Down) with a field of view set to 90°...?
Ah thanks, I'll try that. From what I've searched on google I was told to set the camera to 45 degrees. And I know they're called equirectangular images, I just don't refer them to that because of the way I'm using them (or the way I'm not using them) :P

Design Acrobat said:

If you have Bryce (it was free for awhile) you can make a skybox for games. There are a few tutorials on youtube for this. Basically rotating camera view 0,90,180,270 for the sides (Front, Left, Right, Back) and then top and bottom views in X (90 and - 90 I think) This gives the isometric view so it can be mapped on a cube.
I have Bryce, but I don't think its going to cut it, I need to be able to place lights, prop characters into poses and a lot more. Also with skybox renders, they're not isometric, they do have a perspective to them just not a large field of view.

Can't ell you about the sky box, but in Carrara it's pretty easy to render a depth pass, which is what you describe in your second question. You can add all sorts of render passes. Go to the Render Room, and under Multi-Pass, click add and a window will open with a whole bunch of different options. Select the one you want, click OK and it is added to the list.

Odd I don't have that, I only have G-buffers, which seam to only work on tiff and photoshop files (awkwardly too, it just doesn't add a new layer, just adds depth values to the alpha channel of the colour layer).

this is what GardenGnome does watermarked as trial version,
top bottom next page 5 images forum max
Sorry on a zero dollar budget here Trying to save my money for a good graphics tablet after mine broke. ):

evilproducer

cooldude234 said:

evilproducer said:

Can't ell you about the sky box, but in Carrara it's pretty easy to render a depth pass, which is what you describe in your second question. You can add all sorts of render passes. Go to the Render Room, and under Multi-Pass, click add and a window will open with a whole bunch of different options. Select the one you want, click OK and it is added to the list.

Odd I don't have that, I only have G-buffers, which seam to only work on tiff and photoshop files (awkwardly too, it just doesn't add a new layer, just adds depth values to the alpha channel of the colour layer).

I haven't seen them called G-Buffers since RayDream! What version of Carrara are you using? Standard or Pro?

cooldude234

I'm using Carrara 6 Pro version 6.2.1.18

Also I tried setting the FOV to 90 degrees, but its measured in mm, so the closest I got was 22 mm and I rotated the camera 90 degrees for each side of the skybox, and the edges still don't line up ):