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

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  • What are the settings to look at to make the skin look paler ? I'm playing around with Translucency Color right now.

  • SzarkSzark Posts: 10,633

    I just found out yesterday that reflective glass does not give reflections back without some sort of backdrop on the outside of the window, weather it be the Environment Pane > Backdrop itself, a plane, HDRI or the Sun/Sky. Viewport colour only will not give any reflections back. Now I have no idea if that is Iray or how DAZ3D implemented it. Either way it really messes with compositing in a background.

    Has anyone else noticed this?

  • SzarkSzark Posts: 10,633

    Looks like I found something new then...again. :)

  • mjc1016mjc1016 Posts: 15,001

    I haven't looked at it...but if it is a volume, then it makes sense.  For volumes to work properly there must be clearly defined 'limits' to them.  A defined
    backdrop of some sort would provide that limit.

    Something to try....use modeled glass (squashed cube) and see if that makes a difference.

  • SzarkSzark Posts: 10,633

    Tried a cube and plane it makes no difference at all. I tested this extensively over many hours trying different things and the result was always the same. LOL make sense to you mjc cause you know this stuff but for me used to 3DL it didn't even occur to me. A bit of a pain really but something I can and will get around.

  • kyoto kidkyoto kid Posts: 35,504
    edited December 2015

    What are the settings to look at to make the skin look paler ? I'm playing around with Translucency Color right now.

    ...I posted a similar question on the Fiddling With Iray Skin Settings thread: Here's what I was learned (and it does work).

    Adjust the Translucency colour and weight (the lower the weight the more "paler").

    Remove all unneeded maps like Translucency and SSS

    Adjust the Gamma of the skin map using the Image Editor (note: not the Layerd Image Editor) in the Surfaces Tab. The farther below 2.2, the lighter the skin tone but don't go too low or the colour becomes unnatural. If, when you open the skin map it is already set to 0 that means it is using "auto Gamma" and you will need to manually set it to your preference.  You will have to do this separately for each map (face, arms, torso etc...).

    Here's what I did for a character that used the Josie 7 Iray skin map which "out of the "box was too dark for my need.

    Removed the Translucency map (there was no SSS map), set the Gamma to 1.8 and the Translucency weight to .3.

     

     

    Leela j7 Iray map..png
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    Post edited by kyoto kid on
  • mjc1016mjc1016 Posts: 15,001
    Szark said:

    Tried a cube and plane it makes no difference at all. I tested this extensively over many hours trying different things and the result was always the same. LOL make sense to you mjc cause you know this stuff but for me used to 3DL it didn't even occur to me. A bit of a pain really but something I can and will get around.

    And in the most recent builds of 3DL, proper volumetric glass (actual thickness to it) is needed, too.  As to this...like I said, I haven't played with it, so I can't say 'why', if it isn't volume based.  But knowing that it is required does help.

  • SzarkSzark Posts: 10,633
    edited December 2015

    Oh I realise the glass with volume is better in Iray (didn't know about the latest 3DL, cheers for that) but having to have a backdrop of some description was a surprise. But yeah knowing it makes things easier hence why I posted my findings...to help others that might have had the same problems but alas it seems I am the only one that found it.

    So you said it was probably Iray that needs it, is that certain or just an educated answer cause I sure would like to know for sure.

     

     

    Post edited by Szark on
  • Gr00vusGr00vus Posts: 340
    edited December 2015

    To clarify - you're saying there's nothing else outside the window in the scene, right? If that's the case, I don't think the viewport/background color gets factored into the iray render. You need something outside the window for the window to reflect in iray, iray (being a physically based renderer) can't fake a reflection if there's nothing to reflect. Maybe you could try putting the image you want reflected on a  simple plane prop outside the window (with the image side of the plane facing the window), parallel to the window just off screen? That would probably get a reflection onto the window for you and allow you to composite. 

    Szark said:

    I just found out yesterday that reflective glass does not give reflections back without some sort of backdrop on the outside of the window, weather it be the Environment Pane > Backdrop itself, a plane, HDRI or the Sun/Sky. Viewport colour only will not give any reflections back. Now I have no idea if that is Iray or how DAZ3D implemented it. Either way it really messes with compositing in a background.

    Has anyone else noticed this?

     

    Post edited by Gr00vus on
  • SzarkSzark Posts: 10,633

    No you don't get the reflections of what is on the inside of the building/structure etc. I realise if there is nothing outside then it won't reflect what is on the outside. I know what Iray is compared to 3DL and we can't fake things like we can in 3DL. What I am saying is that if you don't have a backdrop, plane, HDRI or Sun/Sky it will not reflect anything that is on the inside like lights, furniture etc etc. 

  • Gr00vusGr00vus Posts: 340

    So the interior window surface doesn't reflect the stuff its facing on the inside of your structure? That is weird.

  • SzarkSzark Posts: 10,633

    yes that is correct unless you have some sort of backdrop as explained in my first post about this.

  • Arnold CArnold C Posts: 740
    kyoto kid said:

    Here's what I did for a character that used the Josie 7 Iray skin map which "out of the "box was too dark for my need.

    Removed the Translucency map (there was no SSS map), set the Gamma to 1.8 and the Translucency weight to .3.

    Looks nice. smiley

    Some people use the term "SSS map" for the maps that reside in the "Translucency Color" texture slot.

     

    Szark said:

    I just found out yesterday that reflective glass does not give reflections back without some sort of backdrop on the outside of the window, weather it be the Environment Pane > Backdrop itself, a plane, HDRI or the Sun/Sky. Viewport colour only will not give any reflections back. Now I have no idea if that is Iray or how DAZ3D implemented it. Either way it really messes with compositing in a background.

    Has anyone else noticed this?

    Hi, Pete. 

    Iray ignores viewport colors and backdrops, for it they're simply something non-existant. Iray needs something "physical", a colored or textured mesh to be reflected. You're able to see the backdrop in your render, because the render of your objects is layered over the backdrop. Similar to how it was done in the old days of the movie industry, where they used so-called "Matte Paintings" to have something in the background of the scene which was too expensive to build for the set.

    If you use a simple plane "Primitive" and slap your backdrop texture on it, you will get reflections. Positioning of lighting is a bit tricky, because your backdrop plane will cast and catch shadows. A bit of a drawback if you want to use something like the nice old "Millennium Environment" scenery.

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  • SzarkSzark Posts: 10,633

    Yeah that is cool Arnold thanks man, good stuff for reflecting the environment, excellent points. However it showed me to be more specific as when in Scene only lighting mode a Black Backdrop via the Environment Pane will give you reflections of what is on the camera's side of the glass like interior props and lights etc) . Which is more my point and not reflecting the environment isn't the issue.

  • Gr00vusGr00vus Posts: 340

    Is there a light source inside the structure? If so, where is it in relation to the window and the objects that should be reflected?

    Szark said:

    yes that is correct unless you have some sort of backdrop as explained in my first post about this.

     

  • SzarkSzark Posts: 10,633

    Trust me it isn't about light, the interior is well lit with an additional a row of lamps only 5 or so inches away from the windows. As I posted earlier about this issue I have tested it and if you use Scene Only light and glass (plane or cube) you have to have some sort of backdrop including the the Backdrop colour via the Environment Pane to get reflections of the well lit interior on the inside of the glass. I would surmise that is will work with an image placed there too but that I haven't tested as it didn't occur to me until now. LOL I tested using the well lit scene and as soon as I used Backdrop > Black (thinking along the lines of a mirror) the reflections popped out saying "here we are", nice and crisp. This is when I tested Dome ON, dusk lighting and again reflections, HDRI reflections, Viewport Colour only, Black no reflections. Arrrrrrrrrrrrrrrrr 

    I see what mjc is saying about real world physics etc and I assumed a 3DL mentality and assumed the engine was more clever than me. :) 

  • RafmerRafmer Posts: 547
    Szark said:

    I just found out yesterday that reflective glass does not give reflections back without some sort of backdrop on the outside of the window, weather it be the Environment Pane > Backdrop itself, a plane, HDRI or the Sun/Sky. Viewport colour only will not give any reflections back. Now I have no idea if that is Iray or how DAZ3D implemented it. Either way it really messes with compositing in a background.

    Has anyone else noticed this?

    I noticed the same about the bloom effect. Emissive surfaces won't have bloom if there is nothing behind in the camera view. Even inside the a building; if there is a window behind the emissive object and there is nothing outside; the bloom won't work. I uploaded an example with a lighsaber cheeky.

    bloom.png
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  • SzarkSzark Posts: 10,633

    Rafmer what happens if you go to the Environment Pane and engege Backdrop and use the coloir black and rerender? You are just using Scene Only lighting?

  • RafmerRafmer Posts: 547
    edited December 2015
    Szark said:

    Rafmer what happens if you go to the Environment Pane and engege Backdrop and use the coloir black and rerender? You are just using Scene Only lighting?

    Yes, it's scene only lightning and yes, the bloom effect works when adding a black backdrop color.

    bloom2.png
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    Post edited by Rafmer on
  • SzarkSzark Posts: 10,633

    thanks for sharing that Rafmer, it bits like this that help us all learn what is what and what we can and cannot do.

  • Gr00vusGr00vus Posts: 340

    Can you try it with the window surface set to use a mirror or reflecive solid metal shader and see if you get reflections? I'm asking as I have a hunch that this has to do with the way light is being propegated/bounced around by the renderer. It seems like in both your cases, the effect you're trying for doesn't happen if there's nothing behind the window/object for light to bounce off of.

  • SzarkSzark Posts: 10,633

    oh yeah I get reflections on all the metal within the interior itself and yes if I make the window an opague reflective material is does give reflections no problem as one would expect. So yes when in Scene Only lighting mode you need a Backdrop, HDRI and Sun/SKky Draw Dome On or at least a plane, plain coloured or image based present to get interoir reflections of windows.

  • Gr00vusGr00vus Posts: 340
    edited December 2015

    So it's something to do with the glass shader. Have you tried different glass shaders? I wonder if playing around with the index of refraction might do something. Maybe fiddling with the opacity a bit. Seems like the shader you're using is relying on light bounced back/emitted from another object behind it and passing all light through if there isn't one.

    Post edited by Gr00vus on
  • RafmerRafmer Posts: 547
    Gr00vus said:

    So it's something to do with the glass shader. Have you tried different glass shaders? I wonder if playing around with the index of refraction might do something. Maybe fiddling with the opacity a bit. Seems like the shader you're using is relying on light bounced back/emitted from another object behind it and passing all light through if there isn't one.

    I don't think it is because of the glass shader. Bloom effects don't work on an empty space either if lightning is set to scene only.

  • Gr00vusGr00vus Posts: 340

    I saw that. I haven't used bloom (my current computer can't really handle it), so I don't know what settings are possible for it.  I'm just curious to see if changing the glass shader properties would have any effect at some point.

    Gr00vus said:

    So it's something to do with the glass shader. Have you tried different glass shaders? I wonder if playing around with the index of refraction might do something. Maybe fiddling with the opacity a bit. Seems like the shader you're using is relying on light bounced back from another object and passing all light through if there isn't one.

     

    Rafmer said:
    Gr00vus said:

    So it's something to do with the glass shader. Have you tried different glass shaders? I wonder if playing around with the index of refraction might do something. Maybe fiddling with the opacity a bit. Seems like the shader you're using is relying on light bounced back/emitted from another object behind it and passing all light through if there isn't one.

    I don't think it is because of the glass shader. Bloom effects don't work on an empty space either if lightning is set to scene only.

     

  • SzarkSzark Posts: 10,633
    Gr00vus said:

    So it's something to do with the glass shader. Have you tried different glass shaders? I wonder if playing around with the index of refraction might do something. Maybe fiddling with the opacity a bit. Seems like the shader you're using is relying on light bounced back/emitted from another object behind it and passing all light through if there isn't one.

    nope I played with IOR, roughness, reflection strength etc etc. 

  • evilded777evilded777 Posts: 2,387
    Szark said:

    yes that is correct unless you have some sort of backdrop as explained in my first post about this.

    I remember a thread similar to this in a forum for that other figure posing software and one of the resident experts went about attempting to take a photograph with reflections similar (from the inside) and demonstrated that in reality such a thing was really quite difficult.  At least that's how I remember it. 

  • SzarkSzark Posts: 10,633

    This is true if there is a lot of light outside in the enviroment but it should act more like a mirror in the fact that if is dark outside then the reflections become more prominet and I found this to be true of Iray.

  • evilded777evilded777 Posts: 2,387
    edited December 2015
    Szark said:

    This is true if there is a lot of light outside in the enviroment but it should act more like a mirror in the fact that if is dark outside then the reflections become more prominet and I found this to be true of Iray.

    hmm... actually it was through a window into the night, if I recall correctly

    Post edited by evilded777 on
  • SzarkSzark Posts: 10,633

    Yeah I tried that and in Iray the reflections came out pretty crisp and this is one a single plane mesh but it works the same for glass with volume.

    ON a side note: I also found if the glass is not real world thinkness then you will get double reflections, one from each face of the window, one internally and one on the camera side of the glass.

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