Loading...
> >

Horizon Height for HDRI Dome - how to?

AndySAndyS Posts: 1,438
in Daz Studio Discussion

Hi,

 

in a different thread I already got the solution to adjust the height of the horizon using the Sun-Sky iRay setting. The parameter "Horizon Height" was really usefull.

But now with purchasing the "Skies of iRadiance" I found, that the horizon height parameter isn't available using an HDRI for the entvironment. It doesn't matter what skies or DAZ4.8 devault setup were used.
Depending on the adjustment of the camera and the base environment of the scene, it is necessary to adjust the horizon level of the iray dome to fit with the limits of the set.

But how to ??

Even using "finite Sphere" the parameters for "Dome Origin" nor "Dome Orientation" (y-axis I hope) don't show any effect.

Andy crying

Comments

  • SzarkSzark Posts: 10,634

    have you tried the Z axis

  • AndySAndyS Posts: 1,438

    Hi Pete,

     

    why Z?

    As I understood, the x/y/z - Origin should be the offset of the Dome along these axises.
    So Y is (should be) responsible for the movement up/down. But none of the movements worked.

    Or was your answere just a shot into the dust?

    Only large values for x-/z-Orientation result in strange effects of the sky rendered. Y-Orientation without any effect at all.

     

    Andy

  • SzarkSzark Posts: 10,634

    LOL  yeah I concur with your thoughts until I did a render the other day and wanted the HDRI higher so after trying Y and tried Z and it looked like it went higher.

  • Tako YakidaTako Yakida Posts: 548
    edited December 2015

    Have you tried parenting the dome to a null (if parenting is possible with that dome) and moving the null? I find nulls help in so many unexpected ways with things.

    If it's not parentable, the way I have fixed this problem in the past is parent the whole scene to the null, then rotate the null on x or z (with the camera parented as well).

    If something goes weird like G3F turns to spaghetti when parented, just unparent everything once rotated and it returns to normal.

    Post edited by Tako Yakida on
  • SzarkSzark Posts: 10,634

    The Iray dome is a virtual one and no geometry exists Tako

  • DAZ_SpookyDAZ_Spooky Posts: 3,100

    If I recall correctly, you can only translate a finite dome. 

  • Tako YakidaTako Yakida Posts: 548

    No problem. My second option would be what I recommend in that case. If you rotate the entire scene using a null as a pivot you can effectifely change the horizon unless the dome detects the position of the camera and adjusts itself, in which case we would have been thrwarted by the dastardly fiendish dome gods. :)

  • AndySAndyS Posts: 1,438

    Yep,

    Tako Yakida said:

    No problem. My second option would be what I recommend in that case. If you rotate the entire scene using a null as a pivot you can effectifely change the horizon unless the dome detects the position of the camera and adjusts itself, in which case we would have been thrwarted by the dastardly fiendish dome gods. :)

    that exactly is the dilemma.
    "The dome detects the position and orientation of the camera and adjusts itself."

    This is because it is a virtual one and only generated by the nVidia render engine.

    As I told you in the opening post, only for the sun-sky-only dome you have an option to adjust the horizon hight. This is missing as soon as you apply a HDRI sky map.

    I don't think, it is the fault of nVidia. Perhaps it is one of the million of bugs in DAZ. A missing link in the interface.

  • Steven-VSteven-V Posts: 727

    I am not sure how you would adjust the horizon in an HDRI map. It's a sphere. You are inside the sphere, at its center point. How exactly are you going to move the horizon "up?" If you move the dome up, the center point moves up with it.

    You can rotate the sphere around the center point -- I do that all the time, at least horizontally (I assume you can rotate it vertically but I have not needed to so I can't say for sure). So you could rotate the horizon to have one side higher and one lower (I think). But you can't move the whole thing "up" because there is no physical "up" to move it to.

    In Sun/Sky you have the option because the sky is dynamically generated/calculated and not taken from a 360 degree image map.  Effectively, every time sun/sky renders, it creates its own image map with a clear blue sky, plain dirt ground, and sun disk in the requested position. You can see this in reflective surfaces after a render.  Because it is generating the sky each time you render, you can ask it to just put the dirt in a lower part of the sphere, and it can do that. 

    But if you have a map already, how is the engine supposed to know which part of the map is what you consider a 'horizon' and adjust it? Each image is unique and the horizon may be lower or higher on one image than another. And if it did somehow move the image along the inner surface of the sphere, that would result in stretching on one side and squeezing on the other and you would get a distorted looking image.

  • AndySAndyS Posts: 1,438
    edited December 2015

    Hi Steven,

     

    I think, there are special rules related to building the HDRIs to match sky and ground.

    But the problem of the horizon related to the environment of an individual scene-set, please let me demonstrate it using the sun-sky setup.
    In the attached picture you see my environment, the sand dunes. Depending on the position and orientation of the camera, the horizon of the iRay Dome appears more or less above the landscape's limits. Using the Sun-Sky setup there is a parameter to correct the position of the horizon, so it is covered by the landscape's limits (pull the horizon down). But applying a real HDRI there isn't any chance to do it anymore.

    To your remark of the dynamically generated sky image: It doesn't matter whether using sun-sky or HDRI, the horizon of the render result is in the same position (if I have a horizon height = 0 correction).

    Horizonhight_Demo.jpg
    400 x 360 - 17K
    Post edited by AndyS on
  • vwranglervwrangler Posts: 4,901
    edited December 2015

    Since you're using a finite sphere, have you tried using the Ground Origin sliders?

    The attached is an HDRI-only render from one of Dimension Theory's sets. The first has the Ground Origin Y set to the default, 0. The second has the Ground Origin Y set to -200.

    The Ground Origin sliders are near the bottom of the Environment section of the Render panel.

    groundOrigin0.png
    892 x 816 - 866K
    groundorigin-200.png
    892 x 816 - 398K
    Post edited by vwrangler on
  • AndySAndyS Posts: 1,438
    edited December 2015

    Hi,

     

    good hint.
    But why didn't you talk about the other parameters? Such as "Ground Position Mode" had to be chnaged against the Default.

    Generally: If you have larger sets (mine is ca. 50 meters in all directions from the origin) you need a larger dome to get your set equally illuminated.
    And as I saw: The ground origin not only changes the horizon height - it lowers the complete dome. So it influences the angle of the sunlight, too.

    DomeHeight_for_HDRI.jpg
    370 x 871 - 76K
    Post edited by AndyS on
  • Gendragon3DGendragon3D Posts: 176

    Thanks so much for the tip, I was looking for this for a while without getting a solution for my work and thanks to this topic I found the solution!

    Gendragon3D
    My freebies: https://www.sharecg.com/pf/gendragon

Sign In or Register to comment.