Thank you Jason for this awesome texturing advice. I've done a lot in photoshop with tiles and spherical texture maps, so this is my territory.
Some of these procedures i'll have to read over a few times to really get completely, so I hope you don't mind if I need to ask a couple questions about them at some point. Thanks! Nancy On Jun 24, 2014, at 2:17 AM, Jason S <jasonsta...@gmail.com> wrote: > In my experience, a textured sphere can work pretty good, > > You can tile an image (3-4 times on a sphere) > with a tilable "base star texture" (as uniform as possible) > large enough to hold enough subtle variations without perceiving patterns > (perhaps 1.5-3x the size of your final render res), > > If you are using Photoshop, from a say 1or2k rez. small-star starfield pic, > (to make a 2-3k final pic) you can do a 'filter->offset' by any odd amount, > and then breakup the seams to make it tilable -- super-easy specially for > stars, > you can use a speckly brush clone stamp with high opacity (so no opacity > gradient falloffs) > and a low brush step, (so 1 stamp at every ~20 pixels on strokes for very > random cloning) > > > So you can make a relatively 'mostly uniform ' star map density as a base > BG, > ( with many-many dim (almost subpixel) stars, a a number of mediums, and > really just a couple of bright ones, all with a bit of cloudy variations ) > if there arent enough dimer ones, or to add density or (uniformize?), > you can use a big clone stamp with that speckle-y brush, but in additive > (linear dodge) mode at varying opacity > also with that now-tilable pic, you can scale it down 50% & tile it 4 times > in half opacity (linear dodge) for those many faint BG stars > > Then, with those hubble pics, you can isolate interesting areas, make the > rest transparent, > and in 3d, add grids in key spots to add localized cloudy nebula patterns and > variations depending on what you're after > (with RGB intensity as opacity) > > If you really need 360 (up & down) with a spherical projection, > you'll probably want to mix-in a copy of that starfield texture for any > stretching at the poles of the sphere. > > I used a very speckle-y gradient (made of "fat noise") with a white to black > radial "fat noise gradient" in the center as an alpha for the same stars > texture, to project vertically top down (x-z) > > You can also blend the star textures somewhat more than 1 in 3d so that some > stars can "bleed" a bit with perhaps an additive blurred version of just > those hot pixels. > > That may be enough on it's own, but if you are moving around (at light > speed?) > you can also add 3D stars, Adams tips seems like an excellent approach to > that :) .. good luck! :) > > Jason > > > On 06/23/14 17:50, Adam Sale wrote: >> Do you need nebulae, etc? >> If its just stars, what about using a static point cloud with spherical / >> displaced randomized spheres as shape. Randomize color and transparency per >> point? >> This would give you the 3d field you are looking for, then perhaps some >> fluids to do neb clouds, simulated particles for comets, meteors etc.. >> Perhaps use the hubble images or comp some stills together to make a bg >> cyclo to pull the 3d elements together? >> >> Adam >> >> >> On Mon, Jun 23, 2014 at 2:42 PM, Nancy Jacobs <illus...@mip.net> wrote: >>> Hello, >>> >>> I'm needing a star field kind of background for a scene, and looking for >>> ideas to create it. I have been using Hubble images wrapped around a >>> sphere, around the scene, but I'm finding it doesn't read well, even with >>> very high-res Hubble images. >>> >>> So, I'm wondering about other ways to create star fields. Has to be 360 >>> degrees, seamlessly -- and I don't have the capability to deal with that in >>> a compositing situation. >>> >>> So....any ideas? >>> >>> Thanks, >>> Nancy >
