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Lights NOT working

OminousAutumnOminousAutumn Posts: 388
in Technical Help (nuts n bolts)

I cannot for the life of me get consistant illuminiation. I am using Iray rendering with 5 different point lights each with the same default setting aside from illumination values which range from 15,000-25,000. The render settings are on default but I am seeing nothing. My first render showed tons of illumination but now everything is dark. It seems that one light is working but not the others. I am on the "public shower" scene and at a total loss. Maybe my render settings are incorrect. Maybe there is a maximum number of lights that can be used? I have a "clouds" image as my background. I am beside myself with frustration from the inconsistant results that I am getting from this software's lighting as I have no idea what the variables are that make it work one minute and then now, not. The image attached should likely be very bright considering there is any illumination at all, as well as my first render at the same stage of stopping it, was overexposed.

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Comments

  • FishtalesFishtales Posts: 6,119
    edited September 2015

    As far as I can see from your screen shots you are using Intensity for the lights instead of the Luminous Flux to increase the light output.

    Have you checked the beam length to see if the light is actually reaching the girl?

    Post edited by Fishtales on
  • OminousAutumnOminousAutumn Posts: 388

    I think that may be the answer, thank you. 

  • OminousAutumnOminousAutumn Posts: 388

    I cant seem to get any lit background image to appear. My background under the environment tab has a set of clouds selected. I just want overcast daylight, how do i achieve this? The environment map or the backgroud or both?? On the left is after the render, and the right is how it looks pre render. Not sure how to do this...

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  • FishtalesFishtales Posts: 6,119
    edited September 2015

    Increasing the Environment Intensity and/or map will increase the light coming from the HDRI. Each works differently though. You will alos have to reset the Tone Mapping settings to compensate for the extra light.

    http://docs.daz3d.com/doku.php/public/software/dazstudio/4/referenceguide/interface/panes/render_settings/engine/nvidia_iray/tone_mapping/start#white_point

    Try reading through this and see if it helps.

    http://docs.daz3d.com/doku.php/public/software/dazstudio/4/referenceguide/interface/panes/render_settings/engine/nvidia_iray/environment/start

    Post edited by Fishtales on
  • IceCrMnIceCrMn Posts: 2,129

    you also forgot to turn on the dome :)

    It's the "Draw Dome" button,When it's on the image will show in the render.When it's off you just get the light from it.

  • OminousAutumnOminousAutumn Posts: 388

    Those are helpful thank you. But does the HDRi need to be of a certain resolution? Does any picture cast light, or are the HDRi's you download the only pictures that will cast environmental light? Thank you for all your help. 

  • FishtalesFishtales Posts: 6,119
    icecrmn said:

    you also forgot to turn on the dome :)

    It's the "Draw Dome" button,When it's on the image will show in the render.When it's off you just get the light from it.

    I missed that blush

  • IceCrMnIceCrMn Posts: 2,129

    We've all done it :)

    The HDRI is a special image type so other image types may give some light, but HDR and EXR are the two I've liked the most.

    The most important thing is the number of exposer levels that it has, more is better.Some of the better ones are around 400MB in size though.

    Here is a link to a post that can do a better job of explaining the more technical parts than I can.There is also a good list of where you can download them for free.

    http://www.daz3d.com/forums/discussion/57531/list-of-sites-with-free-hdri

    This one is of the Pixar campus, and is very popular.

    https://community.renderman.pixar.com/article/107/luxor-jr-panorama.html

  • SpottedKittySpottedKitty Posts: 7,232

    Any picture type will cast light... sort of... in an environment setting, but only an HDR type will do a good job. It's right there in the name — High Dynamic Range. The image is built up from several standard images, so that e.g. in a landscape, the shadows are very deep and the sunlight (if there is one) is very bright. Note that this is usually a lot more dynamic range that most monitors are capable of displaying, so you can't really see the difference if you view the image. This is also why the usual image file format of jpg shouldn't be used for an environment image, they can't handle the HDR part of the business, and the extra dynamic range is stripped out. If the environment image isn't a .tiff then it should be an .hdr or one of the other specialised HDRI formats.

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