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

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  • IceDragonArtIceDragonArt Posts: 12,468
    Khory said:

    Tabor, I guess I am looking at it from the new user perspective. If they load that shader and render with no changes they get what is basically a dark yellow that casts no light. For them it is not just a funky outcome but pretty worthless and off putting. I'm not talking about potential since most new users expect a shader preset to just "work". At least with the Uber defaults they won't get a muddy yellow that they have to start out with. And solving "why isn't it  bright enough" is less complex than solving "why is it so ugly". Having or choosing to adjust presets is not a negative if your in tune with what they are expected to do and how they do it. But if your a new user that isn't always clear or easy and it really is a better deal for them if they "work out of the box". When they give a result that seems counter to the expected outcome that can be really off putting for a newer user.

    I understand how emissive lights work but I'm not actually a newbie to Iray. In fact I just finished a light set that uses both the photometric and the emissive lights in order to get the look that I wanted. And I have been working on emissive shaders and lighted props on and off for over a month. I tend to use kcd/m^2 for the same reason you use cd/cm^2, because you can use lower luminance settings which I think are easier to fine tune.

     

    This is totally true.  I have been here about 4 months now and still find Iray to be completely overwhelming.  When I purchase a shader or texture I do expect it to work with a minimum of hassle.  Mostly because in many ways, I still have no idea what I am doing despite my pages and pages of notes.

  • Oso3DOso3D Posts: 14,414

    Any guidelines on the lowest/best settings you can set Firefly filter with?

    I THINK a lot of my renders come out a little too blurry, but I have no clue. Change it to box and 1 pixel? Professor in the library with the wrench? Meep?

     

  • FishtalesFishtales Posts: 5,346

    @Will

    I generally keep the Firefly off, when on and the Nominal Luminance is set it turns off or at least affects some other things like a volume mist, snow sparkle and the Bloom Filter.

    The Pixel Filter I have set for mitchell and Pixel Filter Radius set at 1.20 for my renders which are 1440x960. The setting depends on the number of pixels in the image. I found out in Photoshop when working on photographs that the more pixels there are the bigger radius that can be used to sharpen them.

  • Oso3DOso3D Posts: 14,414

    Yeah, I'm inclined to go without that automatic stuff and just clean it up in post. Mmm. Will have to experiment.

     

  • KurzonDaxKurzonDax Posts: 228

    Your scenes must not be ventilated enough.  

    A Gaussian filter pretty much by definition results in blurring.  This isn't a bad thing, since a digitally rendered image without any blurring will likely look decidedly unrealistic.  The 1.5 pixel radius that defaults is way too large IMHO for an average sized render.  I usually run it down to somewhere between .9 and 1.1, depending on what I'm looking for and the size of the render.  As FIshtales said, the larger the render, the larger the radius can be.  

    Having said that, I'm also partial to using either Mitchell or lanczos(sp?) for generating a sharper end result.  Those tend to give results that resemble the final sharpening I would do to a photo in Photoshop.  

  • Oso3DOso3D Posts: 14,414

    Yeah, so far I've been doing a render at default values and then running it through a Sharpen in GIMP, which seems to produce a decent result. It worried me a little why I seemed to need to use it so much...

     

  • ZilvergrafixZilvergrafix Posts: 1,378
    edited March 2016

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    Post edited by Zilvergrafix on
  • KurzonDaxKurzonDax Posts: 228
    edited March 2016

     

    This is the edited version of this post because I was pretty much an uncalled for jerk in my original.  Major sincere apologies to Zilver sad

     

    Bump maps are actually pretty useful with Iray.  It's probably not necessary to convert them to a normal map yourself, since Iray actually converts bump maps to a normal map internally anyway.  Doing it yourself using one of the online tools (like http://cpetry.github.io/NormalMap-Online/ ) gives you a bit more control, but the end result probably won't be much different than what Iray will do on it's own.  Leaving it as a bump map, however, gives you the flexibility to still use a regular normal map.

    Using a bump map, in addition to a normal map, you can take advantage of having two levels of detail.  However, bump maps should typically be used for details that don't need to be visible from any angle.  Generally, the features provided by a bump map are best visible when looking straight on, or somewhat off to one side or the other.  For example, bump maps are perfect for skin pores because pores are small, and do not necessarily need to be visible from all angles.  Bump maps also perform an excellent job of breaking up specular reflections, adding a level of realism.  

    The real problem, as I see it, is the general and pervasive lack of bump maps that have been built properly.  Taking a diffuse map and just desaturating it is not how a good bump map is made.  Ideally, a bump map is generated the same way a high quality normal map is, by extracting details from a very high-resolution version of the model.  This isn't always practical, unfortunately, so the desaturation method was probably born.  It's still possible to acheive a decent bump map by manipulating a diffuse texture in Photoshop, or via some of the tools that are available out there, but it requires some effort.  Probably the best results I've seen came from a trial version of CrazyBump.  Unfortunately, buying it is ridiculously expensive. On the positive side, it also generates some really good normal maps as well.

    Reflection or specular maps can also be useful, depending on how much realism you're looking for.  With the exception of metallic or very glossy surfaces, specular highlights on real objects are rarely even.  This is especially true of natural human skin.  Even wet skin doesn't give perfectly even specular reflections.   Other surface made of organic materials are often the same.  Take, for example, a varnished wood surface.  Even though the varnish provides a certain amount of glossiness, the underlying roughness of the wood, and the uneven thickness of the varnish results in uneven specular highlights.  Specular maps simply attempt to approximate this.

    Transparency maps are useful in circumstances where not using them would result in enormously excessive geometry (e.g. trans-mapped hair) or where the effect simply can't be produced effectively with geometry (intricate lace). 

    The bigger concern with using all these maps is that they start adding up when it comes to the amount of RAM your scene will be using on your video card.  Bump maps, and even normal maps in some cases, quickly do become useless the further away from the camera an object is.  The same is true of specular maps.  If an object is going to be in the background, or blurred from using depth of field, you'll save some RAM space by eliminating unnecessary maps.  Doing this for one or two objects probably won't make that much of a difference, but if there are lots of objects, each with their own set of maps, it can start to quickly add up.

     

    Post edited by KurzonDax on
  • KurzonDaxKurzonDax Posts: 228
    edited March 2016

    On the topic of HDRI maps.  The real problem is that most people (myself included) tend to use freebie HDRIs from various sources, since high quality HDRIs tend to be expensive.  The problem is these freebies generally just aren't very well made.  There is a reason quality HDRI maps cost money.  They take work, and skill, to assemble correctly.  However, tons of money doesn't need to be spent for quality.  I have seen some very good results posted in these forums from people using the DimensionTherory HDRI maps available here in the store.

    On the other hand, I have rarely seen or produced good results with many of the free maps found using the hdrlabs website.  The problem is most of those maps simply lack the dynamic range needed to adequately light a scene.  In many cases, they are nothing more than a group of low dynamic range photographs stitched together to give a 360x180 spherical image.  You could create the same thing with the camera on your cell phone and some photo-stitching software.

    Post edited to remove more jerkiness.

    Post edited by KurzonDax on
  • ZilvergrafixZilvergrafix Posts: 1,378
    edited March 2016
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    Post edited by Zilvergrafix on
  • KurzonDaxKurzonDax Posts: 228
    KurzonDax said:
    Sorry to totally rain on your post, but I don't think it's helpful to have new users thinking all these maps are bad and must be removed when that is factually not the case.

     

    Ok, flag my post for some moderator delete my contribution and save the world, no problem.

    You know what, I owe you an apology.  My response above was way too heavy-handed.  My intentions were good, but I was pretty tired and cranky last night, so I shouldn't have responded at all.  I'm going to reword the post to make it more constructive, and less like an absolute jerk.  

  • mjc1016mjc1016 Posts: 15,001

    There are some free HDRis with decent range...you just have to look for them.

    That said, try some of the Noemotion ones (they allow commercial use), the Aversis (non-comm only) and OpenFootage (even the free versions have decent range and the pay versions with much higher range are failry inexpensive).  And Greg Zaal's HDRIHaven has some decent ones (again the free ones are lower range but the full versions are pretty inexpensive).

  • Oso3DOso3D Posts: 14,414

    One of my biggest pieces of advice isn't specifically Iray, but something someone linked about photo editing, about postwork.

    A GREAT way to correct an image:

    Go into Paint.net/GIMP/Photoshop/whatever, something with layers and common layer effects.

    Copy the image into a second layer

    Set top layer to Overlay

    Make top layer B&W (Desaturate in GIMP, usually luminosity works, IMO)

    Gaussian blur top layer by 1% of the average dimension. IE: if you have a 1200 x 1000 image, blur 11 pixels.

    Adjust opacity of top layer until you get the desired look (I find 30-50% is about right, most of the time)

     

    This approach helps tone balance an image really well, add some sharpness without getting pixelated.

     

  • TabascoJackTabascoJack Posts: 865

    One of my biggest pieces of advice isn't specifically Iray, but something someone linked about photo editing, about postwork.

    A GREAT way to correct an image:

    Go into Paint.net/GIMP/Photoshop/whatever, something with layers and common layer effects.

    Copy the image into a second layer

    Set top layer to Overlay

    Make top layer B&W (Desaturate in GIMP, usually luminosity works, IMO)

    Gaussian blur top layer by 1% of the average dimension. IE: if you have a 1200 x 1000 image, blur 11 pixels.

    Adjust opacity of top layer until you get the desired look (I find 30-50% is about right, most of the time)

     

    This approach helps tone balance an image really well, add some sharpness without getting pixelated.

     

     

     

    I followed your instructions above, and the results definitely look better,  But it just reinforces my belief that I need to sit down and really learn GIMP so that I understand what I just did.  smiley

     

  • KurzonDaxKurzonDax Posts: 228
    mjc1016 said:

    There are some free HDRis with decent range...you just have to look for them.

    That said, try some of the Noemotion ones (they allow commercial use), the Aversis (non-comm only) and OpenFootage (even the free versions have decent range and the pay versions with much higher range are failry inexpensive).  And Greg Zaal's HDRIHaven has some decent ones (again the free ones are lower range but the full versions are pretty inexpensive).

    The Averis one's I've used.  Their monthly freebie that you have to sign up for is usually pretty good, depending on the type of scene you're rendering.  I'll have to try OpenFootage.  Another site for relatively inexpensive HDRIs is 3docean.com.  I've bought a couple from there for around $15 each that ended up working out well.  The only catch there is that the images are produced by independent artists who just sell their work via the site, so the results may vary.  Many of them provide example renders, though, so that at least helps you to get an idea.

     

  • Oso3DOso3D Posts: 14,414

    TabascoJack: If it helps, I have no idea what the heck I just said. I just know it makes magic to picture grunt.

     

  • KurzonDaxKurzonDax Posts: 228

    @timmins.william Yeah, I do that alot with images that need just a bit of localized contrast enhancement.  I don't know if Gimp has a "soft light" blending mode similar to Photoshop, but if the effect needs to be a bit more subtle, using soft light instead of overlay can help.

  • mjc1016mjc1016 Posts: 15,001
    KurzonDax said:

    @timmins.william Yeah, I do that alot with images that need just a bit of localized contrast enhancement.  I don't know if Gimp has a "soft light" blending mode similar to Photoshop, but if the effect needs to be a bit more subtle, using soft light instead of overlay can help.

    There is a wide selection of blending modes in GIMP...I'm not sure if they exactly match their PS counterparts, but yes, there is a 'soft light'.

  • KurzonDaxKurzonDax Posts: 228

    I need to play around with Gimp more.  I pay for a PS subscription everymonth because I use it so much, and because it's what I know the best.  I really should try to get more familiar with Gimp to eliminate that expense.

  • DanaTADanaTA Posts: 11,986
    KurzonDax said:

    I need to play around with Gimp more.  I pay for a PS subscription everymonth because I use it so much, and because it's what I know the best.  I really should try to get more familiar with Gimp to eliminate that expense.

    From everything I've read by users of both, it comes close but no cigar.  Eh, I'm still using Photoshop CS2 and it suits my needs.  For now.

    Dana

  • Oso3DOso3D Posts: 14,414

    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.

     

  • SickleYieldSickleYield Posts: 7,468
    edited March 2016
    KurzonDax said:

    I need to play around with Gimp more.  I pay for a PS subscription everymonth because I use it so much, and because it's what I know the best.  I really should try to get more familiar with Gimp to eliminate that expense.

    Give it a try.  You can't use PS actions but you can use PS brushes, and now the program has a lot of features it didn't when I first got it.  It's always served me well.  I tried a trial version of some edition of PhotoShop a couple of years back and couldn't stand the interface.

    GIMP can't paint directly on a 3D model, mind.  I have 3D Coat for that.

    Post edited by SickleYield on
  • KurzonDaxKurzonDax Posts: 228

    Ok, you all convinced me to give the Gimp a shot.  I'm just so comfortable with PS from using it for years.  I rarely use the actions unless it's for some repeatitive thing I need to do (like modifying a batch of images in some way).  I never use the bazillions of "creative" actions that people have come up with everywhere, so there won't be much loss there.  The brushes are a big thing though because I'm a bit of a hoarder when it comes to those.  

  • mjc1016mjc1016 Posts: 15,001

    One thing about GIMP...it's toolset is constantly expanding.  So if you are looking at tutorials, make sure they are made for the version you are using.  (I just ran into this, because I KNEW how to make text along a path...but that was in the 2.6 and earlier versions, in the 2.8 series they moved the tool...angry)

  • Gr00vusGr00vus Posts: 340

    I use GIMP exclusively, and it's suitable for most of what you'd do in photoshop, though you'll have to track down external plug-ins/scripts and install them to replicate some things. I still haven't found a good substitute for macros in GIMP to help automated repetitive tasks - anyone know how to do that?

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

  • Nyghtfall3DNyghtfall3D Posts: 582
    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.

  • Gr00vusGr00vus Posts: 340
    edited March 2016

    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.

     

    Post edited by Gr00vus on
  • mjc1016mjc1016 Posts: 15,001
    Gr00vus said:

    I use GIMP exclusively, and it's suitable for most of what you'd do in photoshop, though you'll have to track down external plug-ins/scripts and install them to replicate some things. I still haven't found a good substitute for macros in GIMP to help automated repetitive tasks - anyone know how to do that?

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

    Macros, layers and brushes are things being worked on for the next major update (2.10).

    Yes, links to software, especially free, OpenSource software are allowed (other commercial software...if it is something not directly in competition to Daz products is usually fine, too).

  • KurzonDaxKurzonDax Posts: 228

    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.

  • Nyghtfall3DNyghtfall3D Posts: 582
    edited March 2016

    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.

    Post edited by Nyghtfall3D on
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