sIBL-GUI seems cool but no support anywhere

[philvanderloo]

In all of the reading I've done in the past few days on using sIBL file sets for lighting and backgrounds in scenes, sIBL-GUI seems like a cool approach.

Unfortunately I can't seem to get the results I'm seeing in the tutorials.

My 1 -2 minute render time prior to running the script in my exterior render is now 40+ minutes and the outcome is horrible. A very dark scene with a black and grey blurr as a background. (Not to mention Max crashes every 15 minutes)

I have no idea where to even start tweaking and there is really no support to be found anywhere. Why my render time is so ridiculous all of the sudden is a mystery to me. I'm using the LWF render settings in Vray 3.0.

If anyone can point me in the direction of some good tutorials/methods for applying hdri lighting and/or getting sIBL-GUI to work properly I would be very appreciative.

[Chris MacDonald]

I've never understood what advantages using a blurred, low res HDRi as your lighting has over using a high res one and using an 8 bit image as your background over a HDR/floating point image, other than overcomplicating what is an otherwise incredibly simple workflow.

 

Why not just use the "standard" HDRI workflow?

 

Just grab your chosen HDRI and load it into a vray dome light. I can't see how it can possibly get any simpler than that? And with superb quality output too, no hacks or work-arounds. Not to mention that you can make VRay downsample the HDRI for lighting anyway using the resolution control on the VRay Light.

 

I am sure I must be missing something about sIBL.

Edited November 3, 2014 by Macker

[Stephen Thomas]

I do like the fact you get the sphere object linked to HDRI rotation as a visual aid, but I've also stopped bothering with the blurry map. I think the point was that using blurry map in conjunction with a direct light source (colour and intensity sampled from the HDRI by the plugin) would result in faster render times. For some HDRIs with multiple light sources this is perhaps an oversimplification.

 

One thing I have started doing for interiors in particular, is putting the hdri in environment slot then using vray light portals, rather than use a dome light. I seem to get much more bang for my buck in terms of light samples and render quality/time.

[Chris MacDonald]

One thing I have started doing for interiors in particular, is putting the hdri in environment slot then using vray light portals, rather than use a dome light. I seem to get much more bang for my buck in terms of light samples and render quality/time.

 

That's because the environment slot doesn't "do" importance sampling, making the GI/lighting less accurate. But if you're ok with that, that's fine. One of my colleagues used to use this setup, and whilst it rendered faster I really never liked the quality of the lighting; he'd often have to add a VRay Sun to bring out any real depth in the image.

[RyderSK]

That's because it also doesn't do (environment slot) any primary sampling in case of interpolated algorithm (like IR/LC), so you will also get smooth, floaty or blotchy (if you don't use enough hemispheric subdvids) result.

 

The "sIBL" concept is valid, but just Chris said, it's now done automatically in most rendering engines including Vray. The domelight by default has '512px' size. Original is used only as reflection and background.

[TomasEsperanza]

I've never understood what advantages using a blurred, low res HDRi as your lighting has over using a high res one and using an 8 bit image as your background over a HDR/floating point image, other than overcomplicating what is an otherwise incredibly simple workflow.

 

Why not just use the "standard" HDRI workflow?

 

Just grab your chosen HDRI and load it into a vray dome light. I can't see how it can possibly get any simpler than that? And with superb quality output too, no hacks or work-arounds. Not to mention that you can make VRay downsample the HDRI for lighting anyway using the resolution control on the VRay Light.

 

I am sure I must be missing something about sIBL.

 

With so many suggestions of how best to go about lighting with an HDRI, it can be a bit confusing. I'm always farting about with variations on IBL, and can identify with the differing points of view here.

 

I often use Sibl at home when I'm doodling, and want a quick IBL solution for something, and it works for me. At work the results are more specific, thus it's a case by case approach. I nearly always find the scenario benefits from a blurred lighting map; it's quicker and cleaner, and the loss of precise details can be addressed if necessary.

 

Having used sibl to generate sets of various HDRI images (Env, Refl, BG) then I often apply these manually instead of using the sibl GUI.

[philvanderloo]

For the time being, I think applying sIBL manually might be my best option. Although I'm wide open for suggestions and I appreciate those shared here.

I'd still like to know why, when using sIBL-GUI, I suddenly have 40 minute disaster renders. I tried 3 different sIBL image sets and got the same result on all of them.

I tried it with a fresh new simple drawing with just a sphere and a plain and the render time was ok but the final render had a very dark background image and lighting in general. And if I tweaked the sun multuplier, the chrome sphere got blown out but the background didn't change.

Tried changing f-stop and iso and this helped a little but the background image colors were way off on the white balance. I thought it was supposed to be simple.

[Chris MacDonald]

For the time being, I think applying sIBL manually might be my best option.

 

But what makes you think that it is easier than using an HDRi in a Vray dome light? Or in the environment slot?

 

What is it that you're trying to achieve using sIBL that you can't otherwise?

[CliveG]

I am sure I must be missing something about sIBL.

 

I agree, I wasted too much time getting poor results and just gave up on the gimmick and just concentrated on getting the straightforward HDRI dome setup working instead. This now includes adjusting the HDRI's in PS and looking more closely at what it is I'm trying to get out of them and trying to tweak them to suit my work.

 

As many have pointed out in other posts, not all HDRI's are equal, so don't just assume you're getting an apples for apples comparison between HDRI's or I guess sIBL files either. There are good ones and there are very bad ones out there, And though useful they're no silver bullet, flick a switch for magical renders....

[philvanderloo]

OK, OK you guys are beating me into submission.

I have to admit I haven't had any issues when using the hdri dome light routine yet but when I ran across this new platform it sounded like it was the greatest thing to happen in hdri lighting. Maybe not. I'm always keeping the feeler out for new developments but maybe this one needs to brew awhile.

[Chris MacDonald]

You misunderstand, my comments are merely curiosity; I'm not having a dig at you. I thought perhaps you might be after a particular effect, or that you had a workflow that this was best suited to.

 

That HDRIlabs site has been around from way back when HDRI lighting was the "next big thing" from what I remember, it's not a recent workflow that has suddenly appeared. I remember looking at it back when I was using mental ray and thinking what a fantastic idea it was, which must have been 07/08.

 

Then HDRI lighting as we know it took off...

[philvanderloo]

No Chris I was just trying to get a little humor in there.

I really do appreciate your comments. I'm just a Contractor/Revit user and still quite the rookie in the Max/VRay arena and I'm just throwing thoughts out there for some feedback. I'm fairly convinced that your suggestions might be the best approach.

[Chris MacDonald]

Ahhh, my mistake. Sometimes things get lost in (text) translation eh!