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

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  • DAZ_SpookyDAZ_Spooky Posts: 3,100
    edited December 1969

    I apologize if this has already been asked but I didn't see it when I read though the posts. I've noticed that when I use Iray certain things like Vein Set from the MASSIVE Morphs for Genesis 2 Female set won't show up in the Iray render but will show up in a normal render. Is there a setting that I need to adjust? I'm using the Iray sunlight and the Iray preset mat for Gen 2.

    I also noticed that the skirt which shows wrinkling in normal rendering also doesn't show the wrinkling in the Iray render, so I'm hoping it's just me not understanding the settings.

    It depends on how the veins and wrinkles are set up. IIRC both of those are HD Morphs. If I am remembering correctly, it is a simple fix. In your parameters pane there is a new setting called Render SubD Level (Minimum) which will need to be adjusted to use HD Morphs. For most HD morphs a level of 3 is sufficient.
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  • TjohnTjohn Posts: 9,752
    edited December 1969

    tjohn said:
    I've seen some renders by Totte and others that appear to be Dimension Theory HDRI sets, including shadow catchers, in Iray.
    Could someone give some step by step on how this is done? Please? :)

    Shadow catching appears to be automatic.

    Render settings for this image:

    Environment mode: Dome and Scene
    Dome mode: Finite sphere (just because HDR image was too low resolution for infinite sphere and in finite mode theres an option to adjust sphere radius).
    Environment Map: HDR image

    Except for reduced sphere radius, rest of the setting ware default.


    Thank you! I'll try that out. :)

  • macleanmaclean Posts: 1,864
    edited December 1969

    I've been looking at promo scenes from my products in Iray, and I thought you might be interested in the results.

    I'm not keen on the sun-sky environment in Iray. It gives good results, but I prefer a light I can look through to see what's going on. Setting latitude/longtidute, date & time is not my idea of fun, so I'm experimenting with the Photometric light instead.

    Render settings
    Environment - Scene Only

    Tone Mapping
    Ev 13.94
    shutter speed 1/1000th
    f-stop 2.8
    ISO 200

    Photometric light
    Shadow softness - 0%
    Lumens - 200,000
    Temperature - 5000k

    Ceiling light panels - Emissive shader
    Temperature - 5500k
    Lumens - 20,000

    Render 1 - Strong sunlight
    Photometric light - Point

    Render 2 - Weak sunlight
    Photometric light - Disc
    All other settings as above

    Render 3 - Hazy sunlight
    Photometric light - Disc
    Height - 3.00
    Width - 3.00
    All other settings as above

    Render 4 - Medium sunlight
    Photometric light - Cylinder
    Height - 1.00
    Width - 1.00
    All other settings as above

    Render 5 - Default settings
    Photometric light - Point
    Height - 10.00
    Width - 10.00

    Ev 13
    shutter speed 1/128th
    f-stop 8.0
    ISO 100

    All other settings as above

    All render times approx. 10 mins/90% convergence

    The last Iray render at default settings is of course, too dark, but I wanted a comparison. To get a better result, I would have increased the PM's Lumens, upped the film ISO or Ev.

    Re the Photometric light's dimension. Basically, the trick is, if you want harder shadows, decrease the size. for softer shadows, increase it. In photography, fill panels (large white panels) are used to fill in hard shadows and the larger the fill, the softer the shadows will be. so it's the same principle.

    Also, I would have added an emissive shader to the monitor screen, but I can't figure out how to add the texture to it. Can anyone tell me how to do that?

    mac

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  • macleanmaclean Posts: 1,864
    edited March 2015

    As a comparison, here's the original promo rendered in 3Delight.

    I can't remember what the render time was. It has 4 lights - sun, room and 2 fills.

    mac

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    Post edited by maclean on
  • DAZ_SpookyDAZ_Spooky Posts: 3,100
    edited December 1969

    maclean said:
    I've been looking at promo scenes from my products in Iray, and I thought you might be interested in the results.

    I'm not keen on the sun-sky environment in Iray. It gives good results, but I prefer a light I can look through to see what's going on. Setting latitude/longtidute, date & time is not my idea of fun, so I'm experimenting with the Photometric light instead.

    Render settings
    Environment - Scene Only

    Tone Mapping
    Ev 13.94
    shutter speed 1/1000th
    f-stop 2.8
    ISO 200

    Photometric light
    Shadow softness - 0%
    Lumens - 200,000
    Temperature - 5000k

    Ceiling light panels - Emissive shader
    Temperature - 5500k
    Lumens - 20,000

    Render 1 - Strong sunlight
    Photometric light - Point

    Render 2 - Weak sunlight
    Photometric light - Disc
    All other settings as above

    Render 3 - Hazy sunlight
    Photometric light - Disc
    Height - 3.00
    Width - 3.00
    All other settings as above

    Render 4 - Medium sunlight
    Photometric light - Cylinder
    Height - 1.00
    Width - 1.00
    All other settings as above

    Render 5 - Default settings
    Photometric light - Point
    Height - 10.00
    Width - 10.00

    Ev 13
    shutter speed 1/128th
    f-stop 8.0
    ISO 100

    All other settings as above

    All render times approx. 10 mins/90% convergence

    The last Iray render at default settings is of course, too dark, but I wanted a comparison. To get a better result, I would have increased the PM's Lumens, upped the film ISO or Ev.

    Re the Photometric light's dimension. Basically, the trick is, if you want harder shadows, decrease the size. for softer shadows, increase it. In photography, fill panels (large white panels) are used to fill in hard shadows and the larger the fill, the softer the shadows will be. so it's the same principle.

    Also, I would have added an emissive shader to the monitor screen, but I can't figure out how to add the texture to it. Can anyone tell me how to do that?

    mac


    Nice looking Renders.

    First things first. LOL.
    Lat-Long, Time of year/day is only one way to use the sun. You can also use the sundial or just put an object in the scene (Usually a null) and on the environment section of the render settings you can go to the SS Sun Node dropdown pick your object. Wherever you place your object is the direction that the sun is coming from.

    As for adding an image to an emissive shader, set the emission color to white and add your map there, (also put it in the diffuse channel as normal). You may have to adjust the temperature to get a more correct color from the light, though 6500K should give you, about, what you are looking for.

    Your observation on Photometric lights is correct. Think it like comparing a bare photo strobe to a Soft box.

  • macleanmaclean Posts: 1,864
    edited December 1969


    Lat-Long, Time of year/day is only one way to use the sun. You can also use the sundial or just put an object in the scene (Usually a null) and on the environment section of the render settings you can go to the SS Sun Node dropdown pick your object. Wherever you place your object is the direction that the sun is coming from.

    As for adding an image to an emissive shader, set the emission color to white and add your map there, (also put it in the diffuse channel as normal). You may have to adjust the temperature to get a more correct color from the light, though 6500K should give you, about, what you are looking for.

    Your observation on Photometric lights is correct. Think it like comparing a bare photo strobe to a Soft box.

    Yes, I know about the sundial and null, but I still like to look through a light.

    After I posted, I played with the monitor screen and figured out the map had to go in emissive color. I don't have a diffuse channel though, and I had to ramp up emissive to a few billion to get a result.

    Still playing with it though.

    mac

  • Mr Gneiss GuyMr Gneiss Guy Posts: 462
    edited December 1969

    scatha said:
    Right, so the render acceleration is ONLY going to work for people with an NVIDIA graphics card... which seems ridiculous to me.

    Welcome to the wonderful world of video cards. Please note, Nvidia wrote iRay, so of course it is going to work with their cards. And before people slam Nvidia for pushing CUDA, AMD tried the exact same thing with proprietary APIs, which not many people ever adopted http://en.wikipedia.org/wiki/Close_to_Metal

    So, Nvidia is providing a free software to work with their cards. At least they were nice enough to make it work with just the CPU as well.

  • CypherFOXCypherFOX Posts: 3,296
    edited March 2015

    Greetings,

    maclean said:
    Yes, I know about the sundial and null, but I still like to look through a light.
    That's why I use a Distant Light as the object, instead of a 'null' object. It lets me adjust the sun location, while looking through the sun. My one early discovery in the Iray stuff, and it's stood me in really good stead so far. :)

    I also do all the lighting in Watts instead of the default units, because my mind doesn't think in those units, but I sure know what a 120W lamp and 45W light are going to look like.

    -- Morgan

    p.s. Very nice renders! I really love the way interiors get lit with this renderer.

    Post edited by CypherFOX on
  • ReddofNonnacReddofNonnac Posts: 16
    edited December 1969

    Thanks! I'll give it a try when I get home tonight.

    I apologize if this has already been asked but I didn't see it when I read though the posts. I've noticed that when I use Iray certain things like Vein Set from the MASSIVE Morphs for Genesis 2 Female set won't show up in the Iray render but will show up in a normal render. Is there a setting that I need to adjust? I'm using the Iray sunlight and the Iray preset mat for Gen 2.

    I also noticed that the skirt which shows wrinkling in normal rendering also doesn't show the wrinkling in the Iray render, so I'm hoping it's just me not understanding the settings.

    It depends on how the veins and wrinkles are set up. IIRC both of those are HD Morphs. If I am remembering correctly, it is a simple fix. In your parameters pane there is a new setting called Render SubD Level (Minimum) which will need to be adjusted to use HD Morphs. For most HD morphs a level of 3 is sufficient.
  • Zev0Zev0 Posts: 5,325
    edited March 2015

    edited

    Post edited by Zev0 on
  • kyoto kidkyoto kid Posts: 27,827
    edited December 1969

    Dumor3D said:
    Kyoto Kid said:
    ..OK re-rendered and saved to the right folder.

    ...OK have an interesting issue occurring. The three attachments below illustrate an odd anomaly I came observed when rendering a test scene in Iray. I had converted all the glass in the scene to the Iray Uber glass material so as to get the reflections I needed. As can be seen the elements of the shelter's interior line up differently with the window frame closest to the camera. This did not occur in the 3DL render test as can be seen in the attachments below. What appears to be happening is the Iray Uber Glass shader is for some reason distorting the imagery behind it. Same is evident in the bus behind the girls In RL this aberration does not occur unless the glass is very thick and viewed through at an extremely low angle. The glass in the shelter window is seen almost head on.

    In looking at the default refraction for the Iray glass material index in the surfaces tab set at it is1.55 which is on the high end for Crown glass (IOR range of 1.5 - 1.6). Though "physically correct", it apparently creates an unrealistic effect in the finished rendered scene. I tired the Thin Glass material, but it still presented the same IOR issue as the regular clear glass. Lowering the IOR of the glass does help but it also reduces the reflectivity quality as well.

    Wondering if anyone knows of a workaround.

    Fig 1, Screen Shot of the render settings.

    Fig 2. 3DL rendered image.

    Fig 3. Iray rendered image with glass at default IOR

    Fig 4. Iray rendered image with glass set to IOR of 1.0

    Window glass should be set to a refraction of about 1.40. A little change to that setting makes a big difference. Yes, crown glass does and should create more distortion, more reflection and it catches more light within the glass, such as crystal. Generally speaking... the higher that number in the real world equals more expensive crystal. :) Also, yes, if the glass is thick, it will cause more distortion of the objects behind. The same thing happens with real world glass, such as looking through the bottom of a coke bottle.... if you can find a coke bottle anymore.
    ...I actually reduced it to 1.3 (water) and the distortion was still very evident. I'll give the "thin glass" material a try.to see if that helps.

    ...as to Coke bottles, I have a couple as we have Coca Cola from Mexico in the stores here (real cane sugar instead of that high fructose rubbish), and it still comes in the classic glass bottles.

  • kyoto kidkyoto kid Posts: 27,827
    edited December 1969

    Szark said:
    Anybody find a Chrome mat or have any tips of making one? Me just being lazy and trying to save my brain from imploding. :)

    ...couldn't find one, ended up using Titanium for chrome which look pretty good.
  • SzarkSzark Posts: 10,218
    edited December 1969

    Zev0 said:
    edited
    did you get it scaled right then. :)
  • SzarkSzark Posts: 10,218
    edited December 1969

    Kyoto Kid said:
    Szark said:
    Anybody find a Chrome mat or have any tips of making one? Me just being lazy and trying to save my brain from imploding. :)

    ...couldn't find one, ended up using Titanium for chrome which look pretty good. I opted for Nickel as Chrome has got some Nickel in it as far as I know.
  • Zev0Zev0 Posts: 5,325
    edited December 1969

    Szark said:
    Zev0 said:
    edited
    did you get it scaled right then. :)

    Yes sir. Setting scale multiplier to 10, and just dialling the dome radius between -30-10 did the trick.

  • Zev0Zev0 Posts: 5,325
    edited March 2015

    Is there a way to reduce the Z-scale of the dome? when I reduce size to match scale to figure, the fisheyed lense effect is kind of strong.

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    Post edited by Zev0 on
  • SzarkSzark Posts: 10,218
    edited December 1969

    Cheers Zev0 for that info it helps me too.

  • kyoto kidkyoto kid Posts: 27,827
    edited March 2015

    ..substituted the Thin Glass material and light bending looks more natural as well as the reflectivity works. Look like it is similar to Reality/Lux's "Architectural Glass" setting

    OK now I have to figure out how to get a mirror to reflect properly and why I am getting white artefacts in the one girl's hair (the one who is jumping)..

    Post edited by kyoto kid on
  • SickleYieldSickleYield Posts: 7,241
    edited December 1969

    Zev0 said:
    Is there a way to reduce the Z-scale of the dome? when I reduce size to match scale to figure, the fisheyed lense effect is kind of strong.

    I've tried all of the settings, still can't figure this one out myself.

  • Zev0Zev0 Posts: 5,325
    edited March 2015

    I think they need to add scale dials for each axis (X,Y,Z) of the dome. This will be extremely useful..Unless they already exist somewhere and I am just blind lol.

    Post edited by Zev0 on
  • macleanmaclean Posts: 1,864
    edited December 1969

    Cypherfox said:
    Greetings,
    maclean said:
    Yes, I know about the sundial and null, but I still like to look through a light.
    That's why I use a Distant Light as the object, instead of a 'null' object. It lets me adjust the sun location, while looking through the sun. My one early discovery in the Iray stuff, and it's stood me in really good stead so far. :)

    I also do all the lighting in Watts instead of the default units, because my mind doesn't think in those units, but I sure know what a 120W lamp and 45W light are going to look like.

    -- Morgan

    p.s. Very nice renders! I really love the way interiors get lit with this renderer.

    Ah ha! Using a distant light instead of a null is a great tip!!! I'll definitely try that.

    I'm using watts too, but at high levels. I'm about to post some renders. Check the values to see what I mean.

    mac

  • macleanmaclean Posts: 1,864
    edited December 1969

    My experiments on the emissive shader with a texture - in this case a pc monitor with a screensaver.

    Render 1
    Ceiling panels + Emissive shader
    Emission Temperature - 4000k
    Luminance - 3000
    (I kept the ceiling panels' emissive level low, to make the monitor appear brighter)

    Monitor screen - Emissive shader + texture
    Base Color = white + texture
    Emission color = white + texture
    Luminance Units = W (Would it have been too much to use the full word 'Watts' instead of a cryptic W?)
    Luminous Efficacy = 5000

    Render 2
    Luminous Efficacy is set to 20,000. All other settings as above.

    I tried a render at 50,000, but not many monitors give out that much light. It would depend on the rest of the scene and how it's lit.

    mac

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  • SpitSpit Posts: 2,164
    edited December 1969

    maclean said:
    My experiments on the emissive shader with a texture - in this case a pc monitor with a screensaver.

    Render 1
    Ceiling panels + Emissive shader
    Emission Temperature - 4000k
    Luminance - 3000
    (I kept the ceiling panels' emissive level low, to make the monitor appear brighter)

    Monitor screen - Emissive shader + texture
    Base Color = white + texture
    Emission color = white + texture
    Luminance Units = W (Would it have been too much to use the full word 'Watts' instead of a cryptic W?)
    Luminous Efficacy = 5000

    Render 2
    Luminous Efficacy is set to 20,000. All other settings as above.

    I tried a render at 50,000, but not many monitors give out that much light. It would depend on the rest of the scene and how it's lit.

    mac

    Excellent work--thanks for the tips. I much prefer the first because it looks like the bright part of the screen saver is what is lighting the desk. The second one doesn't look natural--like the 'black pixels' of the monitor are sending out as much blue light as the swirly whirly part.

  • evilded777evilded777 Posts: 2,092
    edited December 1969

    maclean said:
    Re interiors

    I'm wondering if object area has an effect on lighting level? In the image below, I set Luminance to 40,000 (from the default 5,000), and although it could definitely be lighter, it's not pitch black. But there are 6 fairly large lighting panels as a single material and I applied Emissive to them. All other settings are at default..

    So maybe instead of trying a candle or ball, you need to use something pretty big. This is just a guess on my part, but in the real world, 6 large panels will give more light than a candle.

    mac

    This is a definite, mac. Something I've learned the hard way with unbiased rendering... IF you want to light an entire scene, your light source is going to have to be physically plausible. A candle in a completely dark room is just not going to light the whole thing. And you need to adjust the tone mapping. Unbiased rendering requires a lot more knowledge of photography than does a biased engine like 3Delight.

    I'm betting you did not change any of the tone mapping settings in that render. If you changed just the Film ISO you'd see the difference. For indoors, I'd start with at least an ISO of 400 and tweak the other camera settings from there.

    There is going to be a somewhat steep learning curve here; one really needs to learn the renderer from scratch.

  • Oso3DOso3D Posts: 12,344
    edited December 1969

    REALLY hope Daz considers a good description of things like Film ISO for us folks unused to unbias. ;)

  • AprilYSHAprilYSH Posts: 1,059
    edited December 1969

    There are quite a few threads and so many great tips and tricks, thanks all and special thanks ...

    I've made a new video on lighting and creating a scene with Iray, for those that have been confused! I've been head-down in this thing for two days and I've done a lot of Googling and reading of PBR docs, so at least it's something.

    Please pardon my voice, I'm still not totally over this pesky "being sick" thing.

    https://www.youtube.com/watch?v=L5FZ5gS9v50&feature=youtu.be

    The biggest thing I'm noticing about converting shaders with the Uber Base clicky is, always check for ambient, SSS and translucency settings. It natively seems to put SSS maps into the translucency channel, where they need to be, but if there aren't those maps you need to turn the translucency value way down.

    Skins that have the colored diffuse put into the SSS channel (Monsterina is one) are now borked. Iray is very sensitive to color in the translucency or SSS channels. DAZ's material for G2F puts Bree's colored SSS map in Translucency, but it's also controlled by a grayscale map in the "translucency weight" channel that was made specifically for this use.

    Basically, if you don't have two maps for that, you're going to want your skin translucency much lower than the .50 DAZ went with on their sample material. Their SSS is mapless. I prefer a specular/glossy shader type on the cornea and sclera and to just turn the reflection layer right off with cutout opacity, but that's a matter of personal preference.
    Posted in the other thread http://www.daz3d.com/forums/viewreply/780607/

    Great video, thank you SY!
    And also a ton of great info on her DeviantArt page I've just discovered cos I'm slow like that :shut: but I assume I'm not alone :coolgrin:, go check it out : http://sickleyield.deviantart.com/

    Razor 42 said:
    I have put together a free Q&D set of light and render presets for use with BETA Daz 4.8 and IRAY.

    See the freebie forum thread here: http://www.daz3d.com/forums/discussion/53797/

    Or go straight to download here: CLICK TO DOWNLOAD

    Thank you DA!

    And everyone needs to bookmark these...


    Nvidia Iray:

    Nvidia Iray Documentation

    Iray Uber Shader:

    Iray Uber Shader Documentation

    These documents are fluid and will change over the course of the beta to add/clarify more information. :)

    Please note that some pages are still being worked on. If you get "permission denied" that page is not yet live. :) As I said, these are fluid through the beta. The pages with the most pertinent info are Tone Mapping, Environment, and the Iray Uber Surface shader pages, and those are all live and available.

  • evilded777evilded777 Posts: 2,092
    edited December 1969

    In this render, I set the light sources (walls and ceilings) to emissive.

    I changed nothing on the lights but to set them to 6500 Kelvin ('daylight').

    However, I changed the tone mapping settings: Flim ISO = 400, F/Stop = 5.6

    This was just a quick render, I changed nothing else... no shaders, nothing.

    The tone mapping settings are still not quite right... but I stink at those.

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  • evilded777evilded777 Posts: 2,092
    edited December 1969

    ok, still nothing special. I toned down the wall lights (5000 kelvin to make them warmer and 1500 luminance), slapped some metal and plastic shaders on the walls and doors and adjusted the tone mapping (ISO = 300, f/stop = 4).

    Even though unbiased rendering is great with light, to think that we can throw away all the tricks we've learned about lighting a scene is a fallacy. You have to think about it differently, but a lot of it still applies.

    This scene is in no way ready for a character or big prop. I'd need some more area lights or spots or points to give my subject the light I am really looking for. All I've done to this point is setup the environment to something like what I would want.

    I hope this information is of some help to someone.

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  • RAMWolffRAMWolff Posts: 8,155
    edited December 1969

    Thanks for starting this thread Jaki. This should be STICKIED DAZ!

  • evilded777evilded777 Posts: 2,092
    edited December 1969

    I realized I should have included a render with the default tone mapping settings so one could easily see the difference (these are much darker appearing on the forum than the renders appear on my monitor.. so I'm still not quite right). Anyway, these are default tone mapper settings of ISO 100 f/stop 8 with the lights the same as the image immediately above.

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