What LIGHTS are ON during a default IRAY render?
Fauvist
Posts: 2,219
in The Commons
I know there's things like domes and suns and headlights in the parameters pane for an IRAY render - but what is CREATING light? If I want to remove all the light(s) from an iRay render, what do I turn off, or delete? I want to be able to put my own lights in the scene, and have them uneffected by default stuff.
Thanks!
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I think you just need to set the mode to "Scene Only" and set the headlamp off either completely (I think it's a setting in the render pane) or at least on the camera you are using. Then the only light in your scene should be from (a) lights you added yourself, and/or (b) any emissive surfaces in your scene.
(Edit to fix typos)
Emissives (and sometimes scene lights) can be difficult to track down when using a pre-packaged scene. I find this product helps me find them quickly:
https://www.daz3d.com/iray-light-manager-pro
To answer the first bit of your question about what is CREATING light - here's what I think is the case (someone please correct me if I'm wrong):
In Dome and Scene or Dome Only mode then it's the bright parts of the image in the environment map that are creating the light. The lighting can be made brighter or dimmer by changing the intensity, and the position by rotating the dome, but you are otherwise limited by the environment map you are using.
In Sun-Sky mode, DS generates a light to represet the sun placed according to the latitude, longitude, time of day and UTC offset hours to simulate where the sun would be in real life - where "Front" in your scene is pointing due South. There are parameters to make the sun brighter or dimmer, but I've not really used them myself.
Try this free light setup http://www.valzheimer.info/2016/11/va2016-rgb-hdri-soft-lights-for-daz.html
While it is a great IRAY light setup, it also comes with a headlamp blocker which keeps your scene lit, when they (headlamps) are all off. Makes it easy to navigate in non iray view when all the lighting is off. I use it for much of my lighting needs.
That's awesome. I never knew what headlamp blockers did. It drives me crazy when my preview is all dark because my emissives and HDRI don't show up in preview (that I'm aware). I've been deleting headlamp blockers because I alway turn off the headlamps. Doh! Gonna try this tonight.
If a scene is too dark to navigate, just use control L and it should make the preview screen much brighter. This will not change how the scene renders.
The default light is the HDRI "DTHDR-RuinsB-500.hdr". The default Environment mode is "Dome and Scene". The default HDRI is decent enough for lighting but doesn't have a real image associated with it.
Defaults can be changed in the preferences.
BTW, as Havos mentioned, CTRL-L will toggle preview lights. Headlamp blockers are a bit of a relic from 3DL, although they can be helpful to people that haven't looked at the Iray options.
I say relic because there are specific places to control headlamps in the Render Settings and Parameters tabs.
The menu point is just misleading - it shows as checked and with a glowing lamp when the light is off, and the opposite when the light is on.
The biggest problem I have is when I lock the focal distance on my camera to something really low (like .01) because I like a camera I can pan around instead of it rotating around a central point. Anyway, having a really low focal distance always lowers the lighting in my scene (Control-L does nothing to help) but the Headlamp Blocker fixes it. So it's mostly a problem I created for myself, but now I have a solution.
Right click to pan the camera without moving it!
Yes, the focal point thing is a bit of an issue, and not something a lot of people would think of. I think it should look alright if you look through the perspective view camera. I tend to create a camera I use only for scene set up, and set this with an appropriate locked focal length to ensure it does not make the scene too dark.
The default light is a HDRI. The quickest way to neutralize its influence is an empty cube textured black surrounding your scene, then you can add lights or emitters to place lighting where you want/need it.
I see the control you're talking about, the one right under the menu icon thingy at the top right? I think I knew about that but forgot it. I'm so used to clicking on the big directional cube. I guess my problem is I'm trying to make everything work like it did in Poser, when this is a whole different can of worms. That's usually where I get myself into trouble.
The command is "Preview Lights" - when it is on the actual lights in the scene are used (well, the first seven in most cases - OpenGL is mostly limited to eight lights, one of which is the headlamp), which may make the area being viewed dark, when it is off a pseudo-headlamp is used instead, so the lighting is constant.
The quickest way to neutralize the HDRI influence is to set Render Settings>Environment>Environment Mode to Scene Only.
You don't have to make the cube, texture the cube, position the cube, and worry about moving the camera outside of the cube. Why use a workaround when you have a direct solution in the software?
No biggie either way, what I suggest uses the same daz studio software, create menu/primitive/cube. done
I would just put it to scene only in render settings, then under edit, delete all lights in case the scene came with any, which will give you a black scene. Then use the light bulb icon so you can see the scene in texture mode, add and position your lights (look through each light to place correctly). Then go to your camera making sure headlamp is off, switch to IRay and your scene is lit!
OK, I interpreted "Preview Lights" as some kind of lights that you could use if no other lights (like Camera Headlamp) were turned on. Therefore it seemed a bit odd that the scene might go black if I set them to On, and vice versa.
The way to think about the Preview Lights feature is as a verb -- preview the light(s). And it only works with scene lighting; that is it is limited and really designed to help visualize the modelling of spot, point, and distant lights you have added. It does not preview emission lights or the Iray dome light, both of which can only be interpreted by the Iray engine in real time.
If you've done studio photography using those big umbrella lights the Preview Lights setting is akin to turning on the modelling light inside the umbrella. It casts a light that can be used to gauge the lighting of the flash -- which you cannot visualize any other way except by taking a picture.
How the Preview Lights feature works when there are no scene lights is a bit of an oddity, but the On/Off setting is only for posing, and does not affect the rendering of the scene.
If you make a black cube, and then you create a light in the distance, won't the cube block the light? Or is there some setting to make the light go through the cube?
I think he's saying make the cube big enough that you can place lights inside it to light your scene. At least that's what it sounds like, but I could be wrong. In terms of rendering efficiency, I think switching to Scene Only, or just setting the environment intensity to 0 would render fastest. If you do the black cube, that's an extra object that all your light paths have to bounce off of. In my experience, the open sky scenes always render faster than ones in an enclosure.
Back to your original question, like some one already said, delete (or make invisible) all lights so your render is totally black. Then add the lights back (or add new lights) one at a time so you know exactly what's happening. The more of a control freak you are, the closer your renders will be to what you envisioned.
Thanks, good to know it doesn't affect the render, I use to turn it off before rendering but I guess that's not necessary then.
Question:
I am new to Daz Studio, and I am curious to know if that HDRI image be replaced with something else? I can see that there is an image there under Rendering - Environments.
Thank You
When I was a Poser user, I used to pray we'd get preview lights, because 99.9% of the time I forgot to turn off the "preview" lights I set before rendering (because all lights in Poser DO render unless you turn them off). I love DS's preview lights. LOL
:)
Laurie
Yes you can plug in any other HDRI... that's the beauty of having it. There are commercial HDRI sets that will change the image automatically.
Here's a link to sites with HDRIs, some free and some not.
@jukingeo And here is a link to Iray HDRs in the Daz store.