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

jakibluejakiblue Posts: 5,435
edited December 1969 in The Commons

There must be more than just me who is a total newb to this Iray rendering thing - and who are sitting here scratching their heads going HUH???

LOL. I thought I'd start this thread and see if those who are doing wonderful things with it, could give some basic tips and tricks, for all us newbies who have absolutely no idea what to do.

Things like:

What are the lights? What does the Sun Dial do and can you move it? What are these Photometric Spot Lights?

Tips on getting hair to look good.

What is that DAZ Material Ball, and what does it do?

What is an Iray Section Plane Mode?

Tips on setting up a basic test render to get a handle on what everything does.

Anyone wanna join in and help out us poor newbs?? :cheese:

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Comments

  • CypherFOXCypherFOX Posts: 3,220
    edited December 1969

    Greetings,
    I'm just as 'n00b' as you with it, but here's a fun trick I did. I pulled up a saved scene, with a distant light, and I deleted all the other lights (it's an outdoor shot) and went into the Render Settings, changed 'Engine' to 'NVIDIA Iray', selected Environment, Dome, Sun-Sky, Direction, and set the 'SS Sun Node' to 'Distant Light 1'. I hit render, and the sunlight was coming from the same place as the distant light had been. Neat trick; not sure if I should have done anything to the distant light (maybe I'm double-lighting?) but it was a really easy way of setting the direction of the sunlight.

    -- Morgan

  • TotteTotte Posts: 9,390
    edited December 1969

    I only have tested it a little but I think hair looks great using Translucency Weight to like 20% and a darker color as Translucency color.

    At least when I tested in the NVIDIA IRay preview mode.

  • Herald of FireHerald of Fire Posts: 3,450
    edited December 1969

    I'm still trying to figure out how this is all supposed to work. Is it biased? Unbiased? If it's the latter, why does it have a progress bar considering most unbiased engines go on forever?

    I worked out that at the current rate my (rather small) render would take around 12 and a half hours to complete if left to its own devices. It seems incredibly slow, even when compared to engines like Luxrender. I've tried using optimized materials as well as playing around with the lighting, but nothing seems to change the slow render times. Annoyingly, cancelling the render seems to nuke the image as well, so I can't just get it to a 'good enough' state of affairs.

    It's all terribly confusing, and there is scant little documentation on how best to set up a scene for it so I've merely been setting up images as I would for Luxrender. Apparently, that's a bad idea.

  • TotteTotte Posts: 9,390
    edited December 1969

    I'm still trying to figure out how this is all supposed to work. Is it biased? Unbiased? If it's the latter, why does it have a progress bar considering most unbiased engines go on forever?

    I found under Render Settings -> Progressive Rendering some settings, like Rendering Quality and Max Samples and Rendering Converged Ratio, they all seems to affect when a render is declared as Finished.


    I worked out that at the current rate my (rather small) render would take around 12 and a half hours to complete if left to its own devices. It seems incredibly slow, even when compared to engines like Luxrender. I've tried using optimized materials as well as playing around with the lighting, but nothing seems to change the slow render times. Annoyingly, cancelling the render seems to nuke the image as well, so I can't just get it to a 'good enough' state of affairs.

    Cancel the render not on the render view but on the render dialog/sheet, and the render view is still there. If you look in the DAZStudio log file it looks like you can see which devices are used in the render. IRay uses VRAM it says, and if your VRAM on your card cannot hold the scene for rendering, it will fallback to CPU.


    It's all terribly confusing, and there is scant little documentation on how best to set up a scene for it so I've merely been setting up images as I would for Luxrender. Apparently, that's a bad idea.

    That's difficult, but using HDR images (I downloaded a few free in the net and used the ones that comes with HDR Pro Sets by DT), seems to give a great illumination.

  • Twilight76Twilight76 Posts: 195
    edited December 1969

    Hm here a few Infos from the Iray 3 pdf i found:
    (Both Sampler can be activate in DAZ to...)

    Iray has new performance features and new shaders

    Architectural Sampler
    1. Employs Metropolis Sampling
    2. Makes interiors and dark scenes converge faster. Useful for:
    1. Interior scenes lit by exterior light through small windows
    2. Light passing through Translucent or Glossy surfaces
    3. Bright light reflected from Glossy and Specular surfaces
    4. Sub-surface Scattering

    Caustic Sampler
    3. Adds caustic reflections coming off of specular and glossy surfaces
    4. Works well with the Architectural Sampler

  • Herald of FireHerald of Fire Posts: 3,450
    edited December 1969

    Totte said:
    That's difficult, but using HDR images (I downloaded a few free in the net and used the ones that comes with HDR Pro Sets by DT), seems to give a great illumination.
    HDR is fine, but knowing how to set it up is a different matter. In Daz Studio, the only method I know of is to use UberEnvironment which, for obvious reasons, is going to be incompatible with Iray. There's an 'environment' in the render settings, but no option to plug in a HDR for environmental lighting.
  • Hellcat-1466942Hellcat-1466942 Posts: 45
    edited March 2015

    I have never used Iray, but I do have some experience with Cycles and a bit of DSLR photography. I can demystify some of the settings

    Pixel Filter
    The pixel filter is the same thing as anti-aliasing. It is a filter that determines how much a ray (or non-ray sample in rasterizers) contribute to a pixel. Examples of filtering types here: http://wiki.blender.org/index.php/Doc:2.6/Manual/Render/Options/Antialiasing#Filtering

    Firefly Filter
    Unbiased engines are only truly unbiased if these are left off. Turning them off unclamps the maximum brightness value of the pixel and certain situations (caustics especially) can produce the equivalent of "clipped highlight." Different engines have different ways and degrees of effectiveness of preventing these while staying unbiased. Iray and the majority of other engines let you turn the caustics off.

    Noise Filter
    The noise filter reduces graininess. As in photography, there is a tradeoff between noise and image quality unless you allow an image to render/expose longer.

    Converged Ratio
    I am not sure what this is as Cycles does not have an equivalent.

    Samples
    Samples number of rays per pixel. This determines how noisy (grainy) your image is. However, it is not the end all, be all of image quality. You can have a high sample count and still have noise, usually dark areas where less rays reach and bounce toward the camera. Distant, small lights and dark scenes in general will lead to a lot of noise, and require more time to converge. The same thing happens when you under-expose a photograph or shoot at high ISOs. There is no hard rule of how many samples you need and the majority of unbiased engines keep rendering until you stop it, but Iray appears to have a hard limit of samples. Better to set it to 15k and stop it when it looks good.

    Exposure Value
    Exposure Value is a measurement of the overall brightness of an image from a given combination of shutter speed, f-number, and ISO. EV0 is the amount of light from 1 second at f/1.0. You can see a table of EVs for shutter speed/aperture numbers here: http://en.wikipedia.org/wiki/Exposure_value#EV_as_an_indicator_of_camera_settings DAZ studio lets you choose the EV and adjusts the shutter speed for you.

    F-stop & Depth of Field
    F-stop is the size of your aperture in relation to the focal length. Aperture determines how large your depth of field is. Larger numbers produce larger depths of field, longer areas of sharpness. Large F numbers reduce the light reaching the image sensor, requiring longer shutter speeds or higher ISOs. For portraits and certain close ups you will want background blur (Bokeh), so smaller F-numbers are desirable. DAZ studio shows the size of your DOF. In Iray, you have to choose the F-number yourself even if you move the EV slider.

    Shutter Speed
    Shutter speed is usually measured in fractions of a second. In DAZ studio shutter speed is an arbitrary x/second value where on cameras they are equal in fractions of a second to fractions (usually 3rd) of a stop. If you are unsure what shutter speed to use, compare your scene to the sample scenes here: http://en.wikipedia.org/wiki/Exposure_value#Tabulated_exposure_values and move the EV slider to match, then adjust as necessary.

    ISO
    ISO in an unbiased renderer is the same as the ISO on a digital camera and ISO on a digital camera is the same as film "speed." Larger numbers are more sensitive to light but are more vulnerable to noise unless you widen the aperture or lengthen the exposure time.

    Post edited by Hellcat-1466942 on
  • TotteTotte Posts: 9,390
    edited December 1969

    Totte said:
    That's difficult, but using HDR images (I downloaded a few free in the net and used the ones that comes with HDR Pro Sets by DT), seems to give a great illumination.
    HDR is fine, but knowing how to set it up is a different matter. In Daz Studio, the only method I know of is to use UberEnvironment which, for obvious reasons, is going to be incompatible with Iray. There's an 'environment' in the render settings, but no option to plug in a HDR for environmental lighting.

    Just plug an image to the image socket there. Then you can control how much light with the other sliders. Set environment mode to Dome and Scene.

  • GreywulfGreywulf Posts: 51
    edited December 1969

    Cypherfox said:
    Greetings,
    I'm just as 'n00b' as you with it, but here's a fun trick I did. I pulled up a saved scene, with a distant light, and I deleted all the other lights (it's an outdoor shot) and went into the Render Settings, changed 'Engine' to 'NVIDIA Iray', selected Environment, Dome, Sun-Sky, Direction, and set the 'SS Sun Node' to 'Distant Light 1'. I hit render, and the sunlight was coming from the same place as the distant light had been. Neat trick; not sure if I should have done anything to the distant light (maybe I'm double-lighting?) but it was a really easy way of setting the direction of the sunlight.

    -- Morgan

    That is a fantastic tip, thank you!

    This means I can create a single distant light in a scene, use the IPR Preview to help position it where I want, render a draft in 3Delight then switch to Iray and link the SS Sun Node to the Distant Light as you show above for the final image. Brilliant!

    For comparison (and to prove it works), here's the same scene rendered in both 3Delight and Iray using the same Distant Light in both, set up as above. The only difference is I applied the Iray Material Preset to G2F (CTRL-Click and Ignore). I think you can tell which render is which :)

    Thank you, Cypherfox!

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  • Herald of FireHerald of Fire Posts: 3,450
    edited March 2015

    Totte said:
    Just plug an image to the image socket there. Then you can control how much light with the other sliders. Set environment mode to Dome and Scene.
    In that very quote you'll note I mention there's no option to put in a HDR map. None of the controls under Environment have image maps so it's impossible to actually add any kind of environmental light, HDR or otherwise.

    If there's another way to access it, I'm all ears

    Edit: Never mind, found it. I had it set to scene only, so there was no option for HDR :D

    Post edited by Herald of Fire on
  • mjc1016mjc1016 Posts: 14,998
    edited December 1969

    I'm still trying to figure out how this is all supposed to work. Is it biased? Unbiased? If it's the latter, why does it have a progress bar considering most unbiased engines go on forever?

    Spooky explained that there are some preset stop conditions...like 95% convergence and a couple of others.

  • scathascatha Posts: 756
    edited March 2015

    Cypherfox said:
    Greetings,
    I'm just as 'n00b' as you with it, but here's a fun trick I did. I pulled up a saved scene, with a distant light, and I deleted all the other lights (it's an outdoor shot) and went into the Render Settings, changed 'Engine' to 'NVIDIA Iray', selected Environment, Dome, Sun-Sky, Direction, and set the 'SS Sun Node' to 'Distant Light 1'. I hit render, and the sunlight was coming from the same place as the distant light had been. Neat trick; not sure if I should have done anything to the distant light (maybe I'm double-lighting?) but it was a really easy way of setting the direction of the sunlight.

    -- Morgan

    All fine and dandy, but what does this 'Nvidia Iray' do for ATI Radeon users?

    Post edited by scatha on
  • mjc1016mjc1016 Posts: 14,998
    edited December 1969

    scatha said:
    Cypherfox said:
    Greetings,
    I'm just as 'n00b' as you with it, but here's a fun trick I did. I pulled up a saved scene, with a distant light, and I deleted all the other lights (it's an outdoor shot) and went into the Render Settings, changed 'Engine' to 'NVIDIA Iray', selected Environment, Dome, Sun-Sky, Direction, and set the 'SS Sun Node' to 'Distant Light 1'. I hit render, and the sunlight was coming from the same place as the distant light had been. Neat trick; not sure if I should have done anything to the distant light (maybe I'm double-lighting?) but it was a really easy way of setting the direction of the sunlight.

    -- Morgan

    All fine and dandy, but what does this 'Nvidia Iray' do for ATI Radeon users?

    Gives you an alternate renderer, that works fine in CPU mode without the need of a plugin.

  • scathascatha Posts: 756
    edited March 2015

    I think you missed the point...

    This is a setting for Nvidia graphics cards, I presume. These will not work the same with Radeon graphics cards, or will they?

    Post edited by scatha on
  • maraichmaraich Posts: 310
    edited December 1969

    Just poking my head in here so I can learn with the rest of you - I hope!

  • mjc1016mjc1016 Posts: 14,998
    edited December 1969

    scatha said:
    I think you missed the point...

    This is a setting for Nvidia graphics cards, I presume. These will not work the same with Radeon graphics cards, or will they?

    No, you missed the point...

    With an AMD card you will not get GPU acceleration. The renderer will work in CPU mode and give the same results, albeit slower than with GPU enabled.

  • Design Anvil - Razor42Design Anvil - Razor42 Posts: 1,094
    edited December 1969

    You only need an nividia card for gpu rendering,if you dont have one the render engine will default to using your cpu instead.

  • FirstBastionFirstBastion Posts: 4,002
    edited December 1969

    Learning this along with everyone else, thanks for the tips thus far.

  • scathascatha Posts: 756
    edited December 1969

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

  • WilmapWilmap Posts: 2,765
    edited December 1969

    What exactly is the Sun Dial Set for and how do I use it?

  • JimmyC_2009JimmyC_2009 Posts: 8,891
    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.


    Since NVidia make it, it doesn't seem ridiculous to me at all. I have an NVidia card, a cheapo one, and it only adds less than 20% acceleration to a CPU render. I may now buy a better card in the future, but for the moment, I can still use it, and get the same result as someone with a really expensive card, it will just take a bit longer.

    I don't see how anyone is being discriminated against.
  • ben98120000ben98120000 Posts: 447
    edited December 1969

    Some documentation:

    NVIDIA Iray

    Iray Uber Shader

  • KatherineKatherine Posts: 274
    edited March 2015

    scatha said:
    I think you missed the point...

    This is a setting for Nvidia graphics cards, I presume. These will not work the same with Radeon graphics cards, or will they?

    All the settings and render results are exactly the same whether using CPU or GPU. The only difference is speed. Iray is put out by Nvidia. Those users who do not have an video card recognizable by Iray will get the exact same final results. This same concern has been answered in each of the threads it was posted in. :)

    Kat

    Post edited by Katherine on
  • Jason GalterioJason Galterio Posts: 1,246
    edited December 1969

    For those that think this might be an expensive investment...

    Last year I purchased an NVIDIA GeForce GTX 750 Ti right off the shelf from Best Buy. Sticker cost was $179 I believe and I had a $20 coupon.

    I pulled out my old AMD Radeon and had the GeForce in, booted up and drivers installed in less that 5 minutes. (It was literally open the case, remove one screw, remove one power connection, pull card, insert card, one power connection, reinsert screw, close case.)

    The GeForce card has 640 CUDA cores, which is the NVIDIA benchmark you should be looking at for GPU rendering.

    AMD uses an entirely different architecture, which is why you can't really have one rendering package that will use the GPU for both NVIDIA and AMD. It's the equivalent of trying to run a Apple program on Windows.

    Of course, just like Apples vs. PCs, there are users that swear by one or the other. I use to be an AMD devotee, but NVIDIA seems to be making a serious effort to attract the 3D hobbyist as well as the gamers. AMD doesn't seem to be as concerned with that now. That's why there doesn't seem to be as much interest in an AMD GPU rendering solution.

    NVIDIA just made it easier and more attractive for programmers to write software to make use of their particular hardware architecture.

    If AMD devotees want to blame someone, they should be questioning AMD. That's pretty much the only way the changes will happen. As long as AMD thinks there is no market, they will not invest in it.

  • ben98120000ben98120000 Posts: 447
    edited December 1969

    In view port, next to "perspective view", is Draw Styles Options menu. New NVIDIA Iray option is added to the menu. It can be used, for example, to preview orientation of HDR image used for environment map light so you can adjust its orientation if needed.

  • SickleYieldSickleYield Posts: 6,968
    edited December 1969

    Hi! Here's my first journal post on this. Later today or tomorrow I will have one on shader settings and what they mean.

    http://sickleyield.deviantart.com/journal/IRAY-519196777

    The things that I've found that are not immediately obvious are:

    1. Turn off the head lamp in your camera settings so you can get real lights. You can create photometrics just as you would regular spots or points.

    2. Turn off your CPU in the render settings if you have one or more good graphics cards, the CPU will actually slow render down.

    3. More lights are faster, not slower, because this is an unbiased/physically based renderer.

    4. Light level in lumens is different from light intensity, and temperature of a light controls its color to a great degree, where lower equals more red and higher equals more blue and then more white (you CAN get green and purple but the light has to be a high enough temperature, say 7000K, that its own color won't overpower it).

  • KatherineKatherine Posts: 274
    edited December 1969

    Ok, here are a couple things you can do with lighting.

    1. Turn any surface into an Emitter. It will cast light. No more fake "ambient". So real light bulbs. :) Or take a plane/sphere/etc and turn it into an areal light....

    To do this, select the surface and apply the Emitter shader you got with the Iray content. (Hold the CTRL key if you want to keep any maps for the surface)

    2. You can use a skydome that ships with a product. I while it is "better" to use an environment HDRI, you can still find a use for the cool domes you may have laying around.

    Follow the steps above and turn it to an emitter. (use CTRL to keep the texture map) You will need to adjust the Luminance value way up....like 50K. (Shader pane > Emitter)

    This little unicorn's horn is glowing and emitting light. :) The horn in the dark is the render without an environment so you can see the result of the emission property.

    Kat

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  • VaskaniaVaskania Posts: 5,920
    edited December 1969

    I think this got lost in the main thread, so I'll post here as well just in case.

    I'm just looking for a little help with using a camera in conjunction with Iray. The camera and the Tone Mapping tab seem to have similar camera settings and I’m not sure if one outweighs the other or what.

  • Oso3DOso3D Posts: 11,647
    edited December 1969

    Ok, 'emitter' alone may win me over to this. Nice.

  • KatherineKatherine Posts: 274
    edited December 1969

    Vaskania said:
    I think this got lost in the main thread, so I'll post here as well just in case.

    I'm just looking for a little help with using a camera in conjunction with Iray. The camera and the Tone Mapping tab seem to have similar camera settings and I’m not sure if one outweighs the other or what.

    Tone Mapper Docs

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