Question about skydomes and other types of backdrops

So, I'm not exactly new but I wason hiatus from DAZ for a few years and while I still remember a lot thereis some stuff that I find confusing and I need to relearn....

On that topic, I'm getting a little confused when it comes to adding backdrops to an environment... I mean, I know how to do that from the scene tab, but sometimes I'm not sure where to get backdrops I need or how to use them. For example yesterday I was trying to add a backdrop but Studio automatically resized it to fit the whole picture, while in osme other cases, like a backdrop that comes with studio, it just fills the view and we use cameras to select the charcters and background we need....

HDRIs are, I think, just light settings

also tried using some cityscapes backgrounds, but they didn't work too well for me (in some cases there is no water, just a horizon......

Or, long story short, could you pooint me out to some tutorials on related topics? Or what are some good backdrops, ideally with landscapes, that Icould use?

thanks for any advice

Comments

  • A model carrying a backdrop image will be cropped for the camera view, like any other item.

  • A model carrying a backdrop image will be cropped for the camera view, like any other item.

    Well, while I appreciate any input this is a great example of a post that doesn't help at all.......

    I'm obviously pretty confused about some major points and about the use of backdrops.... a random sentence that really has no meaning for me is not going to help

    "A model carrying a backdrop" = What does that even mean? Is it English? A model as in a 3d figure of a chick or guy? How can they even 'carry backdrops"?....I understand backdrops are added to a scene

    I mean, if explaining something takes too long point me to some resources or just give me the basics..... that sentence really doesn't halp at

  • WendyLuvsCatzWendyLuvsCatz Posts: 37,945

    Do you want

    a background image

    an environment dome image usually a 360 HDRi

    a cyclorama 

    a curved or straight primitive with an image mapped to it

    all behave differently and have different advantages and disadvantages 

    cityscapes for example are curved and flat planes you stick behind

    a cyclorama of which there are several in store and movie theatre stages and photographers use in real life is a sort of set open one side that can have various backdrops, grounds and transmapped foreground image props added, lighting is very important with it as to not give away the illusion, both in DAZ studio and real life but iray being PBR you can look at photography manuals and tutorials for tips.

    an environment dome provides lighting as well as a 360 image and is like a big sphere encompassing the scene, a HDRi with camera metadata important for DAZ studio to utilise it.

    a background just fits any image to the background stretched or tiled and does nothing to the scene, just as easy to add in post to a png render with an alpha channel 

  • Do you want

    a background image

    an environment dome image usually a 360 HDRi

    a cyclorama 

    a curved or straight primitive with an image mapped to it

    all behave differently and have different advantages and disadvantages 

    cityscapes for example are curved and flat planes you stick behind

    a cyclorama of which there are several in store and movie theatre stages and photographers use in real life is a sort of set open one side that can have various backdrops, grounds and transmapped foreground image props added, lighting is very important with it as to not give away the illusion, both in DAZ studio and real life but iray being PBR you can look at photography manuals and tutorials for tips.

    an environment dome provides lighting as well as a 360 image and is like a big sphere encompassing the scene, a HDRi with camera metadata important for DAZ studio to utilise it.

    a background just fits any image to the background stretched or tiled and does nothing to the scene, just as easy to add in post to a png render with an alpha channel 

    Actually, this is quite interesting....... I guess I'm still not clear on what the exact differences are, or how to use some of them, but this is a start, thanks.

  • My 3D SpinMy 3D Spin Posts: 600

    Create a Primitive plane Size it up to how large background you want - Then create another primitive and
    place as your ground - The background Primitive you go into Surface tab and Basecolor - go to browse
    and bring up the image you want for background. Then if you have some good Ground shader place
    that on your ground- Populate the ground primitive with the props you want - like trees, bushes. Rocks
    whatever.
     

    The good thing about a background like this is that if you use a Camera with Depth of Field  the background 
    will also get blurred!

  • JonnyRayJonnyRay Posts: 1,744
    edited August 2019

    A few of my observations on the information that SadKitty and My 3D Spin provided:

    HDRI images

    HDRI Images are easy to use in Iray rendering (and not terribly difficult anymore in 3Delight) and probably the most common way right now to add a sky or background to your image. They have a few advantages in that they comppletely surround your scene, provide lighting which automatically matches your background (no more shadows going left in the background when the lighting on your figure casts a shadow to the right), and often include a ground texture for a full environment. The drawback is that the quality of the HDRI will drastically affect your experience with them and you are somewhat limited in how you place your figures and props within them since you can't move the dome. Also they have to specifically be designed to support Depth of Focus (DOF) from your camera; so most of them will be sharp and in focus despite looking like the background is far away from your figure.

    Backdrop

    If you want to use the Backdrop feature, you can do it, you just need to edit the image you're going to use to be the size of your render. That will avoid any distortion of the image when Studio tries to make it fit the background. I used that technique for my Neko in Venice image in my gallery. The main advantage to the backdrop over the flat primative is that it is technically "outside" your scene; so you don't have to worry about it blocking lights or remembering to change the angle of the plane if you move your camera.

    Flat Primative with an Image

    For flat backdrops, when you have a sepcific camera angle already setup, using a primitive plane and putting the image on there is the most flexible.

    Curved Primative with an Image

    Several environment sets for sale here use these. The advantage over the flat primative is that the background curves around your set so you aren't limited to only shooting in one direction. This is particularly useful when you're shooting an indoor scene and want to have something ouside the windows but don't want to be limited in your camera angles.

    Skydomes

    By this I mean the "old" way we used to do this which was to create a large half-sphere which covers your entire scene and has an image mapped on the inside. Advantages here are that I get the flexible camera angles like the curved primative, I can move and re-size the dome to adjust to my scene unlike HDRIs, and I get the full sky and surrounding environment. Drawbacks however are that I won't get a ground like with most HDRIs.

    Also, these can cause issues when you're rendering with Iray. For instance, if you set your Render Settings / Environment to use Sun-Sky or load an HDRI sky image thinking it will provide daylight, technically Iray will think there's a solid dome covering everything; so the light you're expecting to come from the Iray environment settings will be blocked by your skydome.

    Cylcloramas 

    For example, the "Millenium Environment" that comes with Studio. These are really falling out of favor. They have an advantage of providing true depth where some elements are closer to the camera than others. And they are lightweight environments on your computer because all of the background items are pre-rendered flat props instead of full 3D geometry, but like Kitty said, you have to be REALLY careful about lighting and camera angles or the illusion is spoiled; so they aren't very flexible.

    No Backdrop

    Finally, I'd be remiss if I didn't also mention that many people will choose to render without a backdrop at all and composite their render over a 2D image using something like GIMP or Photoshop. Since those 2D image editors provide other tools as well for postwork, this can be a great option and is a technique I used for my Walking a New Path image in the gallery. If you're doing this, you'll probably want to learn a little about Iray Shadow Catchers because casting realistic shadows on the backdrop is the trickiest part to this technique.

    Post edited by JonnyRay on
  • HylasHylas Posts: 4,819

    ^ Great overview. I personally use HDRI, backdrop, or no backdrop.

    I wouldn't use no backdrop in combination with DOF. I tried that recently and it didn't handle the transparency of the blurred edges correctly.

    Agent Unawares has several free HDRI's that I can absolutely recommend. They are sky only, no ground or landscapes.

    Era7 has some free HDRI's, as well as several free backgrounds that aren't HDRI. Mostly outer space and toon stuff.

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