Creating HDRI from a scene - how?

Masterstroke

My problem is, when  trying to render a close up scene with Genesis 3 figures in a HowieFarkes environment, I end up having long render times. Right now I am making a comic novel, so I need to shorten render times. So, I' d like to make one sperical render to use it as a HDRI environment. How do I do that? What is the camera setting and how can I get aHDRI from my render?

Kitsumo

To make the sperical render, go to the settings for the camera you are using and then go to the 'lens' tab. Under lens distortion type, select sperical distortion. This should give you the format you are looking for.

As far as the high dynamic part, try this page. Basically, it means you create several images (at low exposure, then higher exposure, and so on for however much dynamic range you want to create), then you load your images into the software they link to, and it combines everything into an HDRI image.

I create sperical images, but I've never tried HDRI, so I can't tell you how well it works. Also, google HDRI creator and you'll get more options.

mindsong

I believe the mentioned camera setting is only available when the IRAY renderer is being used (not available in 3Delight - urg.)

Note that the language in this area is vague, but you can render a simple image (jpeg/png/tiff) skydome for a background (bigger than 2k by 4k pixels recommended), and use any HDR (optionally with additional DAZ-lights) to provide the actual lighting. You usually want the two to be similar (e.g. the light sources in the HDR should eminate roughly where the light seems to be coming from in the skydome... rotate the skydome to match the lights and build your scene from there, etc.)

The capability to build/render skydomes/HDR may also be present in some form with the other rendering products like Reality, Luxus, or Octane, but the controls and settings will probably differ by name and use.

I believe you may be able to render HDR files directly from a scene with one or more of those rendering products. There's probably info in the DAZ forums (look in the Carrara forums too, as there some octane and luxrender users there too, and the ideas probably still apply, even if the buttons are different in DS)

Lastly, there are a bunch of discussions related to rendering both skydomes and HDR in external programs like Carrara, Poser, Bryce, Blender, Vue, Terragen, etc. Some do it natively, some need some external tweaking. Each DAZ forum product usually has a thread or two on the subject.

cheers,

--ms

 

algovincian

You definitely don't need to render out separate exposures and build an HDRI like you would in traditional photography. You can render out the HDRI straight out of DS. I'm not at a computer right now, but look into canvases - you can render out a 32-bit beauty canvas (.exr file) which *is* an HDRI.

Hope this helps.

- Greg

Bobvan

I also use this to make long winded stories and even though I built a 5K 10 core 1080ti machine I can still run into long render times at times. One trick I found to move it along for faster renders is using the BG enviro plane with a photo (1st render) or I will render seperate BG 1st then create a DOF effect with POS then render characters with made up DOF effect renders in minutes (3rd render) 2nd render took approx 3 to 4 hours..

Masterstroke

algovincian said:

You definitely don't need to render out separate exposures and build an HDRI like you would in traditional photography. You can render out the HDRI straight out of DS. I'm not at a computer right now, but look into canvases - you can render out a 32-bit beauty canvas (.exr file) which *is* an HDRI.

Hope this helps.

- Greg

This is cool. thank you :-)

mindsong

algovincian said:

You definitely don't need to render out separate exposures and build an HDRI like you would in traditional photography. You can render out the HDRI straight out of DS. I'm not at a computer right now, but look into canvases - you can render out a 32-bit beauty canvas (.exr file) which *is* an HDRI.

Hope this helps.

- Greg

There's also an interesting recent forum discussion w @philw and @MEC4D (and others...) regarding the creation of fake "full dynamic range" HDR images by using LDR (low dynamic range) jpeg/png skydome images via some clever conversion techniques. Folks looking for accuracy, and HDR  'purists', wouldn't be likely to use these techniques often, but someone with an existing LDR (jpeg) skydome that they like, can use that skydome to create a *roughly* correct HDR that can be used to light the stuff under that skydome well-enough to meet their goals (and deadlines :^).

cheers,

--ms

edited: to clarify wording

mindsong

Bobvan said:

I also use this to make long winded stories and even though I built a 5K 10 core 1080ti machine I can still run into long render times at times. One trick I found to move it along for faster renders is using the BG enviro plane with a photo (1st render) or I will render seperate BG 1st then create a DOF effect with POS then render characters with made up DOF effect renders in minutes (3rd render) 2nd render took approx 3 to 4 hours..

"...long winded stories..." - lol! that made me grin.

just for reference, how long did the third render take, once the 2nd render background was generated?, better yet, how long would an *empty* version of that long-rendered 2nd background take? 10 seconds?

cheers,

--ms

Bobvan

Im not kidding most ot my episodes run anywhere from 300 to 500 renders. Yeah empty or with fake DOF a minute or 2. Point I was making using pictures is you dont HAVE to have HRDI's since one can take pics with their phone all they want..

mindsong

Bobvan said:

Im not kidding most ot my episodes run anywhere from 300 to 500 renders. Yeah empty or with fake DOF a minute or 2. Point I was making using pictures is you dont HAVE to have HRDI's since one can take pics with their phone all they want..

When many folks use the term 'long-winded', it usually has a "won't hush up" or "can't get to the point" flavor to it, so my read on you comment was more of self-deprication than related to your massive numbers of renders. (When folks use that term to describe me, they aren't talking about my rendering...lol). Between your many tests (just the ones you show in these forums!) and the render finals, I gather you beat those 1080s up a bit. heh.

But, backing up your point because that many renders add up on the clock (I animate, so I feel your pain!) it often feels like it's too much work to take the shortcut (pre-rendering the BG and setting matching lights/HDRs), but the savings is actually huge, especially when animating 10s-of minutes at 24fps... Taking the extra effort to pre-render as you've described will shave weeks from a project, and many grey hairs...

This stuff is great!

--ms

Bobvan

LOL at long winded or long stories then they do end eventually... I have killed 2 laptops and the 980 in my previous machine. Lets see how long this rig survives, it does have a crazy heatsink part of the expense.. It usually runs between 61 to 70 degrees..

In the end it does pay off since it draws me commission work which pays for this hobby for the most part..

deafperv

algovincian said:

You definitely don't need to render out separate exposures and build an HDRI like you would in traditional photography. You can render out the HDRI straight out of DS. I'm not at a computer right now, but look into canvases - you can render out a 32-bit beauty canvas (.exr file) which *is* an HDRI.

Hope this helps.

- Greg

All I'm getting is a white file. Can you explain how to do it?

Dresdenskin

rifatgbr said:

algovincian said:

You definitely don't need to render out separate exposures and build an HDRI like you would in traditional photography. You can render out the HDRI straight out of DS. I'm not at a computer right now, but look into canvases - you can render out a 32-bit beauty canvas (.exr file) which *is* an HDRI.

Hope this helps.

- Greg

All I'm getting is a white file. Can you explain how to do it?

The "White File" should be a .EXR file. This is a 32-bit HDR image of the scene as rendered. The exposure of the scene is very high. If you open that file in photoshop and lower the exposure, you would see the scene. You can put the EXR directly into the environment Map channel of the Environment Settings in the Render Settings Tab, but you would likely have to lower the Environment Intensity and Environment Map sliders to very small numbers (less than 0.1 in some cases).

elbiggus

Seeing as this thread has been necroed, I've been fiddling around with this for a while. While it's possible to directy import the generated EXR it's almost invariably waaaaaay too bright, and adjusting it using the Environment Intensity is fiddly and unintuitive, so here's my alternative method. (Also note that the EXR is only any use for lighting -- displaying the resulting dome in any renders you use it in will just give you a washed-out mess. You'll need to do two render passes of your final scene (one as Dome-only using the "normal" render produced below, and one as Scene-only using the EXR dome, maybe with some Node magic to deal with reflections) and then combine them in post if you also want to use the dome as a background.

1. In Render Settings > General set Aspect Ratio (Global) to 2:1
2. In the Advanced tab in Render Settings, tick Canvases and add a canvas; leave it set to Beauty,
3. Place a camera in the middle of your scene, and set Camera > Lens > Lens Distortion Type to Spherical.
4. Render your scene and save it. You'll get the normal render, plus a folder with the same name containing an EXR file. (What resolution you pick largely depends on the type of lighting in the scene -- if directional light is particularly important in your scene then higher is better, but for ambient light you can get away with fairly low resolutions.)
5. Open the EXR file in GIMP[1] -- you'll more than likely end up with an almost completely white image.[2]
6. Go to Colors > Levels... and click on the eye-dropper icon in the bottom right of the window (Pick white point for all channels).
7. Click somewhere in the image and some detail should appear. Now you can see what you're doing, find an area that in your normal render is around medium brightness, and select it. Parts of the image should still look overexposed.
8. Export the image as an EXR (but keep the original in case you need to tweak), and you should now be able to use it as an HDRI lighting environment (And remember, this is only a lighting environment!)[3]

(Screenshot shows, clockwise from top-left, "normal" render, original EXR as imported, and modified EXR.)

[1] Or Photoshop, presumably.

[2] Curious what happens if you have an HDR display.

[3] Not sure if it's a bug or not, but Daz has Environment Intensity and Environment Map sliders in the render settings, and it feels like one should adjust the lighting properties and the other should adjust how bright the "Draw dome" aspect is, allowing you to use the same map for lighting and as a background and save doing two passes, but as far as I can tell they both do exactly the same thing.)

RenderWizard

I've been experimenting with this technique for interior scenes.  I do a 1st environment render for the HDRI of a cramped interior scene, then a second render which uses the HDRI and then has the main figures.  The two-stage process helps me with lighting a cramped scene, and also with minimizing resource use for faster main figure posing, etc.  There are some drawbacks of course (e.g., lighting and reflections don't go back to the environment.) For a lot of scenes the tradeoff is worth it, though. Example attached.

AbnerK

elbiggus said:

...

1. Open the EXR file in GIMP[1] -- you'll more than likely end up with an almost completely white image.[2]
2. Go to Colors > Levels... and click on the eye-dropper icon in the bottom right of the window (Pick white point for all channels).
3. Click somewhere in the image and some detail should appear. Now you can see what you're doing, find an area that in your normal render is around medium brightness, and select it. Parts of the image should still look overexposed.
4. Export the image as an EXR (but keep the original in case you need to tweak), and you should now be able to use it as an HDRI lighting environment (And remember, this is only a lighting environment!)[3]

....

I don't know why Daz overexposes the EXR so much, I haven't really played with it to find out but you don't need to adjust the EXR file once Daz has made it. Just load it in the Environment Map and change the intensity or map setting to 0.0002 or so. 

I was making a Sci Fi scene similar to the one above. I knew it was going to tax my computer but I thought it would be worth it. I didn't realise how long it was going to take though! 

The first one has, so for taken 15 minutes,  the second one took about 10 hours and wasn't good enough to use. They're only a part of the whole image. I should add that the only thing I've changed in the later images, the first and last one here, is the head pose (slightly). I used exactly the same settings to make the EXR file. I think the lighting the HDRI version is much better than the one using the whole scene. I should post the version where I used a png file as the lighting map. The contrast was enhanced in PS for this version. I converted an 8 bit png to 32 bit exr in PS the map had just a few passes to make a usalbe image for lighting. I made it 8k. I wouldn't bother doing that. The one I used Daz's EXR file was only 1k and works much better. 

I think you'll agree that the best light is from the EXR file, the first image. It's certainly the quickest way to get the image. Mind you don't forget I've used the first image as background. I could have done it quicker though without the HD G8M in the scene. 

second_technician_rimmer_9571136c47

I can't seem to find a 2:1 setting?

markusmatern

second.technician.rimmer_9571136c47 said:

I can't seem to find a 2:1 setting?

Just enter the value manually:

1. Open Tab Render Settings
2. Constrain Proportions (Global) On
3. Aspect Ratio W 2.0 H 1.0
4. Change the Pixel Size to your liking
5. (Optional): Save your setting under Dimension Preset (Global)

AbnerK

second.technician.rimmer_9571136c47 said:

I can't seem to find a 2:1 setting?

I don't think Nikola Tesla looked for settings. :)

second_technician_rimmer_9571136c47

I chose the avatar not to compare myself to the guy but because I admire him, Mr Wise Guy 

Silver Dolphin

Just go here >>https://www.deviantart.com/second-circle/art/Quick-Tut-Make-your-own-HDRi-with-free-samples-576276387

Silver Dolphin

This works too>>https://www.deviantart.com/whisakedjak/journal/Creating-a-faux-HDRI-in-Daz3D-and-Photoshop-772301750

second_technician_rimmer_9571136c47

Thanks a lot :) Yahoo, Silver! :3

marble

second.technician.rimmer_9571136c47 said:

Thanks a lot :) Yahoo, Silver! :3

Think you might have meant "Hi Ho Silver" ... don't you love internet pedantry? ;)

Silver Dolphin

marble said:

second.technician.rimmer_9571136c47 said:

Thanks a lot :) Yahoo, Silver! :3

Think you might have meant "Hi Ho Silver" ... don't you love internet pedantry? ;)

Some of the younger generation may not know about the Lone Ranger. hahaha

Ostadan

With his faithful Indian companion Tonto, the daring and resourceful masked rider of the plains led the fight for law and order in the early western United States. Nowhere in the pages of history can one find a greater champion of justice. Return with us now to those thrilling Days of Yesteryear.  From out of the past come the thundering hoof beats of the great horse Silver. The Lone Ranger rides again!

second_technician_rimmer_9571136c47

Sorry to necro this, but there's just one tiny detail I would need to know: how high on the Y axis should the camera be to match the standard level provided in commercial products?

TheKD

I would start around 4 feet or 5 feet. Most HDRI from photos are probably taken on a tripod of some sort, and that's the range of the tripod I have.

second_technician_rimmer_9571136c47

Cheers. I'll try that :)

 

second_technician_rimmer_9571136c47

Is there a way so making just one of these won't take half a day of rendering? ^^;

Also, what min resolution should I use for the render, as not to have a blurry HDRI in the end?

 

superlativecg

Try using denoise filters.