place a light on a hdri?

[rmejia]

How would one rotate the image imported using sIBL, so that the background and sun all move toguether? Also is there any way to adjust the scale, like the palm behind the house for example?

[jujubee]

How would one rotate the image imported using sIBL, so that the background and sun all move toguether?

If you're using the newer sIBL GUI, you would normally adjust everything simply by adjusting the North Parameter in the sIBL GUI. With the latest version, the template slightly broke (there was some renaming internally,) so you'll want just select the model group, and just rotate that. I know... it's not the best solution at the moment. But we've gotta wait until a Maxscript coder volunteers or Dschaga finds the time to hop back on it (the Vray template.)

Also is there any way to adjust the scale, like the palm behind the house for example?

That was kind of the question I was asking in the General thread here about Camera Focal Length, etc. I'm not sure it's 100% possible within Max - at least without plugin.

I was messing around earlier with the offset and the tiling parameters in the environment map copied to a material editor slot. Perhaps that is a temporary fix.

Another solution is to just comp the background out, and put in a flattened image plane that's scaled separately - maybe in post. It's a bit of a hack but the lighting should match up more or less unless you're Superman.

Last but not least, you could manually pop the environment HDR to a sphere surrounding the world, self-illuminate it (I think with Vraylight material - might have to toy with the multiplier) invert so the image is on the back, and scale it up or down that way.

I also wrote Neil Blevins to see if he knew of any solutions regarding cameras and image planes. Hopefully I'll hear back about this.

Other than that, how do you like it so far?

[jujubee]

@rmejia - it looks like your background is comped in both of your images. The reflection and overall lighting isn't changing with the different background whereas it should. If using sIBL with LWF, the lighting/GI should change a lot.

I wrote some tutorials on my HDRSource website regarding its setup and usage.

http://www.hdrsource.com/vray-hdri-t...-installation/
http://www.hdrsource.com/vray-hdri-t...vray-tutorial/

[rmejia]

Thanks for the help jujubee. I actually used your tutorials when installing sIBL, thanks for those.

The image with the palm behind it is the one with the default import settings. The reflection and overall lighting is correct in that one. In the second one I just rotated the background image, so just the location changed and it is still using the original environment settings so it looks off. I tried several different maps and the lighting and reflections changed completely. Before rotating I changed the North parameter, but did not notice any difference. I am using sIBL 2.1.1 and the VRay template 0.9.7

I think I'll wait for the north parameter to be fixed to try rotating again in the future.

Other than that, how do you like it so far?

I think it's awesome, I am impressed . Hope to be using it often in the future. Wish I had a good dSLR camera to try and make some maps.

[jujubee]

I don't know how long that wait will actually be before it is updated - everyone is working a lot and not much free-time. It's probably something somewhat simple but I'm not much of a coder.

Also, make certain with some sIBLs that insert lights, that you have your light within sIBL GUI set to 1000 - maybe even higher otherwise it'll be too close to the world center.

Something's off about those images - and I can't quite put my hands on why. LWF would make a big difference.

[tammo]

The vray domelight has importance sampling for the HDRI domelight now.
It is shooting more rays from the bright parts of the HDRI like where the sun is.

I don't know how good that is working but i think the idea begind that was
to make the manual sunlight placement and HDR blurring unnecessary.

[jujubee]

Someone mentioned that some movie studios will actually go into a HDR and paint out the light sources - filling it in with the software lights instead.

As for domelight, I find it works better (more efficient and less noise) than a standard HDR/EXR in the environment, but I really haven't seen too much of a sharper shadow increase in an image or brighter areas emanating from HDRs.

[BBB3]

Jujubee,
I'm not sure I agree. I get pretty sharp shadows as long as the light source is small and the map's resolution is decent.
Not as sharp as a sun or direct light, but sharp enough for me most of the time. These were rendered with just hdr maps in a dome light.

[jujubee]

Don't get me wrong - I think the domelight can produce much better results and sharper shadows - but I don't think I've ever seen anything that distinctive/contrasty as what you had posted - at least using LWF. I'll experiment in a little bit.

Which HDR libraries are those (please tell me they're not my own)? Depending on the library, some HDRs are "altered" by having painted in an infinitely bright light as a dot on the main light source with an app such Photoshop. This will also cause more well-defined shadows.

One way to tell alteration is to take your HDR into PS and lower the exposure as far as you can go - see if the bright dot still remains there.

This was actually a method that Dschaga who is on this forum came up with a long time ago (http://www.cgtechniques.com/tutorials/synthhdr.php) - but I believe he would recommend against this as he is the main guy who has been working on the Vray template of sIBL.

[jujubee]

Here we go. I'll post the differences with a low test rendering, default settings other than camera F-Stop. Using LWF which is the most accurate rendering method when it comes to gamma and color. The plane is a vray default gray.

When I took this shot, it was about 9-10 am early fall near the waterfront of Boston. It was a very clear sky and the sun was very intense.

HDR in the plain environment slot. You can see it's noisy. No real shadow definition unlike the real world. Un-tonemapped background which defeats the purpose of a HDR to some degree (unless of course you plan on using a backplate instead.):


HDR in the Domelight. Less noise, lower render time, and slightly more defined shadow. Blue overcast which really should only be predominant in shadow areas. I think this is the result of the HDR blur becoming one big, intense light focus:


sIBL. Highly optimized - faster render than the other two. No overwhelming blue overcast. Sharper shadow due to automatic insertion of light. You can also control the intensity and tint if you really want to. It also has a properly tonemapped background in place.


Here's two more starting from the beginning again (domelight versus sIBL - new forum doesn't allow more than 5 attachments in a post.) Admittedly, the sIBL could be less noisy here but I'm only using 750 LC/LC...:

[tammo]

I think the "HDR in domelight" looks more natural than the image produced with sIBL.
Compare the shadows in the real upper part with the teapots shadow.

In the last two pictures there is something wrong with the HDR used.
You need a decent resolution and dynamic range in the HDR.
With such a glaring sun there should be a sharper shadow under the teapot with importance sampling,
just like BBB3s pictures.

Try with another HDR and without LWF
that can mess up a lot.

[BBB3]

Hi Jujubee,
Thanks for the examples. Very interesting.
All hdrs i used in my samples were free ones. Most of them were from the sIBL library (but without sIBL), so there might be some of yours in there.
In order to obtain these shadows, I need to use the full-res HDR, not the blurred illumination map. The images need a good dynamic range too, and it helps of course if there are some very defined light sources in it (the small, blurred maps only produce blurred shadows).
I do work in SWF, so I also almost always apply some gamma correction to the hdr maps upon loading them in max or in the material editor. I know this is anathema, and it means you can't use the hdr as a backplate (which I wouldn't anyway most of the time because of the resolution). As backplate, I tend to use a jpg version of the hdr set at the correct exposure, or just an image map mapped to the screen.
The downside of the methode for me is the slow render time, as the dome light needs pretty high subdivision not to generate noise when the hdr is big and sharp.
Which map in the sIBL archives are yours? All of them? If you point me to one or two of them (those with a clearly defined sun or light source) I could post a render to show you how it looks with this workflow, or tell you exactly which hdr map produces which effect.
B

EDIT: Never mind, Jujubee, I just found your maps (needed to scroll lower down, duh). I'm trying them right away and will post the renders shortly.

[jujubee]

Compare the shadows in the real upper part with the teapots shadow.

??? I don't understand.

In the last two pictures there is something wrong with the HDR used.
You need a decent resolution and dynamic range in the HDR.

The resolution is 8,000x4,000 - higher than most HDRs out there. Dynamic Range is 9 EVs.

With such a glaring sun there should be a sharper shadow under the teapot with importance sampling, just like BBB3s pictures.

As for the "glaring sun", I just used a HDR in the domelight with the first of the last images #4.

#5 is a sIBL with a proper tonemapped image for background and a direct light within the scene - which if you choose, you can turn up or turn down and adjust the shadows manually if you really want to.

Try with another HDR and without LWF that can mess up a lot.

There is no reason "not to" use Linear Workflow. LWF makes certain every bitmap and program works in the correct gamma and color space. So technically, LWF is the most accurate method for Vray and 3dsmax. I've never had it mess anything up - if anything, I get better results with LWF.

Here are some comparisons.

Below is the Vray Sun. Notice the sharp shadow.:


Below is a HDR from 3six0 added to a domelight at default settings. The sun is blasting from the right on a clear day. Instead, all you really see is a shadow underneath the car coming from the sky above. There's an overwhelming blue tint to everything:


Below is a HDR from Dosch added to a domelight at default settings. The sun is blasting again from the right. Shadow seems slight better. There's an overwhelming blue tint. You almost always have to raise the exposure a lot, but the background would really get blown out unless you have a backplate. Technically, you shouldn't really need a backplate, just a properly tonemapped image in there instead:


Here's one of Christian Bloch's HDRs from the sIBL library (the Ref .hdr file without the sIBL - NOT using sIBL) - higher resolution and not blurred and added to the domelight default settings. Shadows are much better, but still this is a perfectly clear day, mid-day, and sun is coming down harsh in the desert. The shadow should be much stronger. The F-stop is lowered (higher - I always get that confused):


And finally, here is the same HDR used, this time using the sIBL as intended. You can see a very sharp shadow. This shadow I would expect from a very bright, sunny day, clear sky, in the desert. Next time you have a very bright day outside, take a look at the shadows - they should be sharp like this.


Ultimately, it comes down to a matter of personal preference as to what you prefer or what you think looks more realistic and what you choose to use. Domelight in my opinion is definitely a great way to go - better than default Max environment. But I personally don't think it can beat, match, or substitute having a Vray light acting as a sun in your scene on top of a HDR.

[BBB3]

OK, here are a few renders done with your maps, Jujubee: HS_Esplanade, HS_ParkingLot and HS_GoldRoom.
As cou see, they give very nicely defined shadows.
This is just using the raw hi-res hdr, with gamma correction and no helper lights added.

[jujubee]

What are your domelight settings - I guess mine work lol... I just left my own tests for the domelight default and render settings were 750 subs LC/LC.