Lighting problem

DaveDave Posts: 207
edited December 1969 in The Commons

I created a scene that i then used an HDR for the background so far so good looks like this
my HDR file came with an ibl file I dont know how to use that so i tried adding a single light from the direction i thought the sun was coming from but it leaves a jet black shadow there is no option to adjust the shadow intensity on this light that i can see.
The HDR on its own dosnt look right as i think the figure should cast a shadow the same direction as the trees

Comments

  • FistyFisty Posts: 3,416
    edited December 1969

    Try using a spot light instead of a distant light, place it about 10 to 15 feet away from the character and scale it up real big, like 500 percent.

  • mjc1016mjc1016 Posts: 15,001
    edited July 2015

    Why do you even need a supplemental light source for shadows?

    She is casting shadows, at about the strength I'd expect for sitting in the shadow of the palm...in fact, I think her hand is a little too strong, for where she is sitting.

    scene-with-no-light.jpg
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    Post edited by mjc1016 on
  • DaveDave Posts: 207
    edited December 1969

    to my eye the shadows on the palms look long and projecting to the right of the picture and the one where i used the light though not ye quite placed right looks correct to me but obviously far too dark

  • prixatprixat Posts: 1,616
    edited December 1969

    A couple of things I've noticed:

    First, as you've shown, the Iray 'Ground' shadow-catcher is not reacting to 'non-hdr' lights properly. With distant lights I get solid shadows and spotlights have no shadows.

    It could be something that's not implemented yet, but worth reporting as a bug!

    Second, sIBL is designed for biased renderers, when I load a set into another program I use both HDR files, and the hires jpg and the 'Sun' from the sIBL setup file.
    With only one HDR, currently allowed in Iray you have much less light and its going to throw the relative intensities off.

  • ShawnBoothShawnBooth Posts: 465
    edited December 1969

    It also appears that you have your light positioned a little too far forward. Based on the BG image, you want your light to be more of a rim type light. Look at the tree trunks and the shadows they cast. Your character's shadow is not at a matching angle to the palms' shadows.

    Why not use a mesh light instead of the spotlight/distant -

  • DaveDave Posts: 207
    edited December 1969

    I think i have a lot to learn about DAZ lighting seems a lot more involved than vues lighting im used to . Ive tried a mesh light dimension theory iradience light that cast its own shadow when placed some where near where i think the light is coming from not sure where Im going wrong with the spot light dosnt seem to be doing anything

  • DaveDave Posts: 207
    edited December 1969

    this is what I get with the spot light

    spot-light.jpg
    1920 x 1080 - 787K
  • mjc1016mjc1016 Posts: 15,001
    edited December 1969

    this is what I get with the spot light

    If you don't have Scene and Dome, then you will only get the Dome.


    If you do have it set for both, then the spot is probably not 'strong' enough...what are your settings for it? The Luminance value will need to be pretty high to overcome the 'strength' of the light from the HDR image..

    And seriously, do you not see the shadow from her hand/arm? It runs, accounting the angle of her arm and the angles of the trunks, in pretty much the same direction as the rest of the shadows and about the same strength. She is in an area where the light is being partially blocked...look at the softer shadows towards the lower left...those are from the palm fronds...and her shadows are slightly stronger to about the same as those.

  • SzarkSzark Posts: 10,634
    edited December 1969

    When using a HDRIs and with the Ground ON you can increase or decrease shadow intensity. The character is casting a shadow under her right hand and left leg

  • mjc1016mjc1016 Posts: 15,001
    edited December 1969

    Szark said:
    When using a HDRIs and with the Ground ON you can increase or decrease shadow intensity. The character is casting a shadow under her right hand and left leg

    And other leg, too...if you look closely enough.

  • SzarkSzark Posts: 10,634
    edited December 1969

    yeah just a tad.

    One thing that hasn't been mentioned yet is that HDRI's will only cast true directional shadows if there is a define sun and not a broad spread of white where the sun is.

  • ShawnBoothShawnBooth Posts: 465
    edited December 1969

    Szark said:
    yeah just a tad.

    One thing that hasn't been mentioned yet is that HDRI's will only cast true directional shadows if there is a define sun and not a broad spread of white where the sun is.

    Excellent tip, thank you.

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