Tips & Tricks for Iray for newbies......

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  • Gr00vusGr00vus Posts: 340

    You will not enjoy GIMP - at least not any version that's been released so far - then. 

    KurzonDax said:

    Oh man, now you guys have me freaking out a little bit about trying to switch.  I abuse the heck out of the text tool in PS for some design work I do pro bono on the side for a non-profit.  I am a steadfast believer in non-destructive editing, so I use and move layers like my life depends on it.

     

  • SickleYieldSickleYield Posts: 7,472
    Gr00vus said:

    I'm also often frustrated by how unintuitively GIMP handles layers. The thing that bugs me the most is just simply trying to reposition them with a click->drag. Even if you have the layer selected in the layers tab, if you don't click on a graphic in that same layer in the work area you end up moving a different layer. Drives me nuts when I'm trying to reposition a layer that's mostly fine details or text.

     

    Anyone had any luck with Krita https://krita.org ? I've heard good things about it, but haven't tried it myself. (Is it o.k. to link to that?)

    Nyghtfall said:
    Gr00vus said:

    Also, the text tool in GIMP is often maddening to work with.

    I've tried GIMP and Photoshop.  Comparitively speaking, Photoshop's UI and text tool are the two principle reasons why I once prepaid for a year's subscription.  I switched to GIMP after my membership expired, and am seriously considering renewing it.

     

     

    Krita is awesome for freehand drawing or sketching.  It is not awesome for working with 3D and textures.  I have it for when want to sketch.

  • DanaTADanaTA Posts: 11,990

    Photoshop does more, but it's also BLOATED.
    I prefer not to have it loaded all the time, so then the fact it takes 2-3 minutes to launch really interrupts my workflow.

     

    I find that CS2 loads really quickly for me.  It used to take a minute or more, but now it's up in maybe 20 seconds, since I upgraded my system to Windows 7 Pro and brought the RAM up to 8 Gigs.  And it's on a hard drive, not the C: drive which is a SSD.  it would load even quicker from there.  Maybe the version you have has more bloat, I don't know.

    Dana

  • Oso3DOso3D Posts: 14,415

    I have no idea, I did the subscription thing about 3 months ago and it was bloated and slow. Mind you, I don't have a SSD.

     

  • Nyghtfall3DNyghtfall3D Posts: 582

    I decided to stop fighting my need to be visually creative, and renewed my Photshop subscription, last night.  CC loads in one second on my SSD.

  • Oso3DOso3D Posts: 14,415

    Repeating an earlier tip after much testing... if you want to get decent godrays in Iray with general haze areas (rather than the Marshian/Sickleyield Godrays thing), you want:

    Generally dark area

    Very bright incoming light

    Incoming light either Distant Light or a point spotlight. (If you use Sun/Sky, you may want to lower environmental weight as much as possible so the light is very directional)

    Distinct gap(s) the light is coming in from.

    Any other light should be coming from, at least, right angles, and ideally coming from the opposite direction.

    A SSS Direction, on the haze, as high as possible. .9 or more -- if you are getting no godrays with this much direction, consider moving the camera or brightening the light, or increasing SSS weight.

    If the entire space fills with haze, revisit above steps.

     

    The thing is, to get distinct, directional haze, you need SSS direction working hard to preferentially react to one light source compared to other light sources. Having that primary light be very bright compared to others helps this process, having a dark room makes any godrays more visible. Having direction of light very different helps you highlight one light's effect vs. others.

    The problem with, say, SSS direction 0 is that all light then gets scattered. You end up with an even haze. The problem with a camera at right angles to the light is that it's hard to 'focus' the SSS effect toward the camera and, again, you end up with haze everywhere.

     

    Anyway, hope this is helpful!

     

  • Oso3DOso3D Posts: 14,415
    edited March 2016

    Additional note:

    Really high SSS direction also means that camera headlamp is actually pretty useful as fill light -- the light is hazed away from the camera's line of sight (though it'll show up in reflections dramatically).

     

    And another ANOTHER note:

    When dealing with scenes with a lot of dark and light, I highly recommend the 'natural' tone mapping: Set 'burn highlights per component' to off, burn highlights to 1, and crush blacks to 0.

    Removing crush blacks is CRITICAL to getting some of the darker shading right.

    Also, if you can, Iray Canvasses with exr output preserves much better dynamic range, if you have a photo editor capable of manipulating that. (I don't, so I don't bother -- though GIMP is due to have 32 bit at some point...)

     

    Post edited by Oso3D on
  • KurzonDaxKurzonDax Posts: 228

    (I don't, so I don't bother -- though GIMP is due to have 32 bit at some point...)

     

    Well, that just sealed the deal for me on trying Gimp.  I can't go without 32-bit support.

     

  • Oso3DOso3D Posts: 14,415

    Yeah, it's the biggest reason, personally, why I'm tempted to go Photoshop over GIMP. At one point I was trying to make HDRs suitable for lighting, and without 32 bit... welp.

    If Photoshop hadn't run so sluggishly I would have stuck with it for that, if nothing else. Maybe if I ever get a better computer...

    And yes, I've tried countless ways to set up HDRIs. They all... stink. Easiest way is simply 'painting in' over the sun in a high dynamic range 32 bit image.

    (MOST of the other stuff never really matters for me)

     

  • KurzonDaxKurzonDax Posts: 228

    Yeah, I hear ya.  Creating a good HDRI is no simple task.  I've been experimenting with creating some HDRIs from scratch that replicate outer space type environments.  I think I did every possible wrong thing one could in trying to come up with something usable.  There aren't really any tutorials on how to create essentially a hand-painted HDRI, and in reality, doing such a thing for a typical landscape type scene would be nearly impossible.  However, for your average star field, there isn't the broad range of luminosity as in an earthbound environment.   I ended up with something workable in the end, and even had a "sun" for a primary light source, but needed to move on to other things so didn't really get it to the point I would consider as "good".

     

  • Oso3DOso3D Posts: 14,415

    I found in pretty much every case it was way easier to do something else, like emissive dome and a sphere or spot or something as 'sun.'

     

  • kyoto kidkyoto kid Posts: 35,526
    Nyghtfall said:

    Photoshop's text tool is like driving a new, fully-loaded luxury car.  GIMP's is like an old, used compact with major engine problems.

    If you can afford to stay with Photoshop, I strongly recommend it.  My only hesitation with renewing is that I can't afford the $120 prepaid annual membership, and I have such a love/hate relationship with 3D art right now that I don't know if I want to commit to a one-year $10/month contract.

    ...for working with text I use PSP.  The text tool is pretty intuitive and easy to use. For filters & effects, Gimp is far more comprehneive especially with ScriptFu and it can use .abr brushes.

  • kyoto kidkyoto kid Posts: 35,526

    I have no idea, I did the subscription thing about 3 months ago and it was bloated and slow. Mind you, I don't have a SSD.

     

    ...same here and I don't have the resources to spare for one.  First priority is to upgrade system memory to 24 GB (yeah, an older machine). Second is getting a 4GB GTX 740 so I can actually use Iray view mode to work with HDRs and render character proofs in GPU mode.

  • kyoto kidkyoto kid Posts: 35,526

    ...OK so can someone tell me why when using the Iray sun (I'm using it for moonlight with the environment intensity turned down) do Photometric lights have no effect on a scene?  Was wanting to use spotlights to simulate lights over doors & such as emissive lights take so long to render and for some reason I'm seeing more instead of fewer fireflies as the render progresses.

    Sometimes I really miss the old AoA advanced lights.

  • Oso3DOso3D Posts: 14,415

    I only have 16 GB RAM (but I DO have a GTX 970).

    As for the sun... it's probably because you are in Sun-Sky Only mode. Which means it's ONLY sun and sky. ONLYYYYYY

    But no fear! Go to Dome and Scene. If there's an environment map, nix it, and voila! Sun operates normally, as well as all your other lights.

    (I've been bitten by that many many times)

     

  • kyoto kidkyoto kid Posts: 35,526
    edited March 2016

    ...already set to Dome and Scene with no environment map (that seems to always block the Iray sun for me).  The "moon" (sun) works fine but none of the Photometric spots show.  I can get items with the emissive shader to work fine but they really crunch the render time. Went from about 6 minutes render time to 42 and still had a bit to go before it would be clean of fireflies (and that's just with one emissive light).

    The Photometric lights show fine in open GL mode but not at all when rendering.

    Also seeing something strange with the render progress monitor, it will show the iterations in sequence, then start skipping some but giving no report on where the conversion % is at and after a couple minutes of this behaviour it will jump from 0% to something like 80% - 90%.  I then closed the scene opened a different one and when I tried to render it the same thing happened. Even after closing and restarting the Daz programme, it still happens.

    Never saw this before until tonight.

     

    Post edited by kyoto kid on
  • Oso3DOso3D Posts: 14,415

    Maybe click on 'defaults' for Render Settings, to see if you missed something?

    That's weird. ;)

     

  • DanaTADanaTA Posts: 11,990
    Nyghtfall said:

    I decided to stop fighting my need to be visually creative, and renewed my Photshop subscription, last night.  CC loads in one second on my SSD.

    Wow!  My SSD is the boot drive and I'm trying to keep it only for the OS as much as possible.  It's only a 120G drive.  But that makes me consider replacing one of my other drives with a new SSD.  Thing is, my other drives are 1TB, 1TB, 500GB.  I can't afford an SSD right now, and certainly not one that could replace one of those.

    Dana

  • kyoto kidkyoto kid Posts: 35,526
    edited March 2016

    Maybe click on 'defaults' for Render Settings, to see if you missed something?

    That's weird. ;)

     

    ...I did a couple more tests and finally kind of got them to work but had to crank the luminosity values way way up and they had only a minor effect, whereas the mesh lights I used were set to  a much more "reasonable" value.   Odd in that when I used them in an RRRR submission which was an interior scene, they worked really well without having to pump up the luminosity anywhere near as much.

    Well the mesh lights give the effect I need so guess I'll just have to bite the bullet and deal with the long render times.

    Gads it would be so nice to have AoA's Advanced Spotlights updated to Photometric.

    Post edited by kyoto kid on
  • KhoryKhory Posts: 3,848

    Emissive lights add render time if they are on higher poly objects. Or if you don't use them to sufficiently lighten the scene for an optimum render time. If you the surface you add them to is low poly they add little to no time to the render. If your putting them somewhere the surface will not show then use a simple 1 poly plane over the surace and you can cut down on render time with that. You can also set the emissives kcd/m^2 and then you won't need to set the luminosity levels so high.

  • kyoto kidkyoto kid Posts: 35,526
    edited March 2016

    ...I'll have to check the sphere and plane again don't remember how many sections each has. 

    I do use the kcd/m^2 setting.  The plane is at 125 kcd/m^2 and set into a window frame off camera replacing the glass, while the sphere 500 kcd/m^2 (as it is further away to simulate a globe fixture over a doorway just off camera and is a "warmer" light).

    Post edited by kyoto kid on
  • Oso3DOso3D Posts: 14,415
    edited March 2016

    What's the luminosity of your photometric lights?

    Can you post a screenshot of the light parameters?

    Post edited by Oso3D on
  • kyoto kidkyoto kid Posts: 35,526
    edited March 2016

    ...currently running a test right now with lower poly primitives (sphere: 8 sides 8 segments, plane: 1 segment).

    The luminosity of the Photometric spotlights is set to 100,000 (they are turned off for now).

    Post edited by kyoto kid on
  • Oso3DOso3D Posts: 14,415

    Oh. That's normal. Photometric spotlights often have to be set in the millions to light normally.

     

  • kyoto kidkyoto kid Posts: 35,526
    edited March 2016

    ...didn't need to do so in this scene:

    The stage and gold angel statues were lit with Photometric spots. Again I'm currently running a test render so cannot look up the settings for this scene.

    such a horrid clang.png
    1200 x 960 - 2M
    Post edited by kyoto kid on
  • TesseractSpaceTesseractSpace Posts: 1,052

    One thing I found to reduce vram usage, beyond just removing objects not in view of the camera, is removing all textures from objects that aren't on camera but might not be removable from the scene for one reason or another (being used to cast shadows from offscreen for example.)

    Given that I'm stuck with 2gb of VRAM, I have to work to keep from dropping to cpu. (The graphics are hardwired and there's no expansion slot, it's a tiny desktop with a very laptop build.)

  • ToborTobor Posts: 2,300
    kyoto kid said:

    I do use the kcd/m^2 setting.  The plane is at 125 kcd/m^2 ...

    If the higher values are a bother, use cd/cm^2; the output is 10X those of kcd/m^2 (1 centimeter-candle is equivalent to 10,000 meter-candles). The centimeter is also D|S's default unit of measure of all lighting fixtures, making cross calculations a little easier.

    One thing that seems to be left out in these comparisons is that the illumination from mesh lights is always diffuse. Be sure that's what you want.

  • kyoto kidkyoto kid Posts: 35,526
    edited March 2016

    ...yes, I am aware of the softness quality of emissive lights which is why I turned to the photometric lights.

    The issue I have is that with the photometric spot and point light, I need to use absolutely ludicrous values to get the same effect that say a 250 watt outdoor light or streetlight would produce in RL. That isn't "real world physics".

    BTW, changing the emissive primitives to as low poly as I could go did little to improve the render time. It still took nearly 4 hours to render the scene that normally took only 6 minutes without the emissive lights.

    Post edited by kyoto kid on
  • macleanmaclean Posts: 2,438

    I just noticed something which could be a bit of a resource-killer. I'd also like to have it confirmed so I know it's not just me.

    I have the Aux Viewport pane docked together with my Scene/Content panes, and today I had it set to Nvidia Iray to see what the scene looked like. After I went back to the Scene pane (in other words, covering up the Aux pane), I noted the scene was sluggish and checked in Task Manager. I was on almost 100% cpu, and I realised the Aux view was still continuing to process the scene. When I reset it to Texture View, the cpu usage dropped back to 1%.

    I had assumed that when the pane wasn't visible, it stopped updating the Iray view, but apparently that isn't the case. Which could mean that anyone with a similar setup to mine, could be wasting a lot of resources.

    If someone else could check this, I'd be interested to have it confirmed.

    mac

  • kyoto kidkyoto kid Posts: 35,526

    ...you mean like Win 10's Cortana, it keeps functioning evne though it's "turned off"?

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