Iray Rendering
Geoffrey_Woodget
Posts: 98
I’m having a problem with some iray products. If I choose ‘Opengl,’ they render fine, obviously not the best quality. If I choose the iray version and render it in iray, it renders out 2 hours later as totally black. If you look through this blackness you can barely make out the image that’s supposed to be there. I’ve Googled till my fingers fell off, I’ve seen others asking, but haven’t found any relevant answer. ‘The Harpwood Trail,’ is just one example.
Thank you
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Hello, Geoffrey. Here are some questions to help us home in on the problem.
It sounds to me like you're not using lights acceptable to Iray. If you're rendering a premade setting, and that setting uses lights designed for 3Delight (or Poser lights), you may well get a black image.
Go back to basics. Restart a new scene. Choose the Iray rendering option, and hit the Defaults button, to make sure all the settings return to their factory defaults.
Load a Genesis character. Check to make sure that that in the Render panel under Environment tab it says Environment Mode: Dome and Scene.
Select the Perspective Camera and render again to see what you get. Hopefully it'll be an image, and not just blackness.
So before I saw your reply, I went to my scene tab, expanded 'High Quality Lights,' and deleted the Sky Dome. Now the render worked. So then I went and removed the whole High Quality Lights folder from the scene, my viewport looked dark now, but it rendered correctly.
What have I learned here?? If there is an iray render option and a light folder for a product, don't use the light folder for Iray? How do you see what's going on?
For a good Iray render it is almost always necessary to render through a camera other than the Perspective view and to turn the headlamp on that camera Off. (Add a camera with the Create/New Camera menu if you don't have a camera in your scene already.) When the camera headlamp is off, your scene may very well look black in the viewport. Luckily there is a way to view the viewport without the headlamp. To turn on the preview light use the shortcut Ctrl L. Ctrl L toggles the preview light on and off. the preview light will not be rendered. It is just for viewing your scene during setup.
If the product has lights and doesn't indicate whether they are for Iray or 3Delight, shame on them. It is not your fault. I don't own The Harpwood Trail, so I can't check that particular product. In general, never load any light set that has a Sky Dome object like that. That is almost always for 3Delight. It is a big upside down bowl that blocks all the light from your Iray environment HDRI or Sky light.
What have you learned here?? 1) Experimentation often leads to success.
2) There are lots of people in the forum who want to help you enjoy Daz Studio. Ask away.
So the 'Lights' catagory apparently are only for Poser & 3Delight? To a new user that's quite confusing. When I choose the iray render, it comes out beatifully, but again, to a new user. before you render there seem to be no scene lights.
Cntrl + L is toggled on, this is the best you're going to get?
So the 'Lights' catagory apparently are only for Poser & 3Delight? To a new user that's quite confusing. When I choose the iray render, it comes out beatifully, but again, to a new user. before you render there seem to be no scene lights.
Cntrl + L is toggled on, this is the best you're going to get?
Preview lights is on by dfault and shows a (pretty weak) preview of the current scene lighting (not the HDR from render settings, or indeed from an uberEnvironment or other light in 3Delight). Ctrl- L turns it off, using the equivalent of the headlamp instead.
It isn't necesary to use a real camera to switch the headlamp off - it's a good diea for other reasons, such as the preview not being saved in the scene. The preview, and all newly creatred cameras, will respect the global headlamp setting in the General group of Render Settings. I would suggest switching the global value to Never and working with Preview Lights off.
Richard already mentioned about Preview Lights, which is a way to get a (sort of) approximation of the modeling of the Daz Studio lighting you're using. Lighting from the Environment Dome (not the same as a skydome in 3Delight) or emissive lights will not show up.
Though it seems counter-intuitive, when you don't have any "real" lights in the scene (just the Environment Dome, for example), you get a brighter view by turning Preview Lights off. This mode casts a sort of modeling light that you can use to pose the scene.
There is another setting that can cause a dim view, and that's the Focal Distance setting for the camera. Sometimes it can get out of whack. Return it to its default (I think it's 450) by Alt-clicking on its value in the Camera parameters tab. That should make the scene bright again.
As for 3DL or Iray light sets: there are a lot of legacy products that came out well before Iray, or are not intended for D|S -- why would a set designed for Poser mention this? You really can't blame them for not indicating what renderer the lights are for. Generally, anything with a skydome that is created by a geometry (you can see it as a half-hemisphere if you zoom all the way out) will not be for Iray.
Boy, I can see now that I was completely wrong in my usage of the term "Preview light". I simply use Ctrl-L to toggle between the states of Off and On and use whichever state lets me see my scene. When I could see my scene, I called that "on". Richard's explanation made me realize that what I referred to as Preview light is really the pseudo headlamp used when Preview light is OFF. Richard knows pretty much everything
, so I will correct my way of thinking about it. Thanks, Richard and Tobor for a more detailed and accurate description of what is happening with the lighting in the viewport. I apologize, Geoffrey, if my incorrect terminology threw you off.
So my understanding now is that the Preview light (on by default) shows an approximation of the scene lighting, not including the HDRI lighting from Render Settings Environment. For scenes lit almost entirely by the HDRI, this will be very dark. When the Preview light is too dim to see the scene in the viewport, using Ctrl-L to turn off the Preview light turns on a equivalent of the headlamp, so you can see the scene in the viewport. I don't believe the Preview light has any impact on the viewport when it is in the NVIDIA Iray preview draw setting, does it?
No, the preview setting doesn't matter for nVidia Iray preview mode (as far as I can tell - my GPU isn't up to routine use of that mode).
The function is clearer if it's understand as the term D|S itself uses: Preview Lights -- Lights with an s. It previews the general balance and position of the light fixtures in the scene (I recall up to 8). It's not just a light for previewing. That is provided, but only if you turn Preview Lights off! the illumination you get with Preview Lights off is a previewing light. I sometimes refer to it as a modeling light, after a similar term in photography.
Yes, that does make the concept even clearer.
7 - or it is 8 but one is reserved for the headlamp. You can control which 7 via the Render Priority setting