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Just as an FYI, in doing some experaments I found that ghost lights made using the little fixer script posted by Jag11 will still work the same in older verstions of DS. Not sure if that is of any help to you @KindredArts
I have purchased (and continue to do so) many of KA's products; I own all the Ghost Light kits and also find them invaluable! However, I for one, would not be in favor of paying for the same functionality that I have already paid for just to get them working in a newer release of Studio; I made the switch to 4.20 primarily for the ground volumetics found in the environment tab and had no idea that it would "break" ghostlights. In any other part of IT, when a commercialy available product is updated and there are "extensions" coded against a previous release, then the Release Notes of the new upgrade is a flag to developers to update their products (free of charge to a customer) to align to impacts indicated in the Release Notes in advance of the Product Upgrade (or closely timed) so as to minimize/reduce impacts to customers. This is product support and I would expect all Content Artists impacted by a Daz Upgrade to freely update their products to provide Customers the value they have already paid for... This is certainly not the popular opinion on this thread, it seems, BUT I do not intend to pay for the same product functionality twice.
I know, thanks. I see it in "product library".
However... will KA's rereleases loose compatibility with older DS?..
I have done a bit of testing on the proposed workaround mentioned here. I set the opacity to 0.000001 and then simply multiplied the Luminance by 1000000. Attached is a test scene and a couple of renders.
I am also seeing said fireflies. Ever use the denoiser? I know I do from time to time if I want a quick render. The first image is done without any filtering. The second with the denoiser turned on.
Sorry, where is this script available? I must have blinked and missed something.
The script is here: https://www.daz3d.com/forums/discussion/548061/iray-ghost-light-fix-dse-for-daz-studio-4-20-o-later#latest
Thanks for the link.
Cheers,
Alex.
Thank you! This fix works for me, and when the fix is available, it is easy to tune back to normal values. Unfortunately, my scenes are full of ghost lights, and this update was a disaster. Now I can relax.
Thankfully, I don't need to reference a lot of older scenes... I will still be waiting for updates to sets relying on ghost lights for future projects - One of the library sets ("Ye Olde Library") I have relies on ghost lights. I can render with the set with some adjustments, and I really do need to practice more with lighting anyway. I can still understand the frustration for everyone who have a legacy of scenes and having more renders to do in a project that they now have to revisit older renders to make things consistent, or that they're unhappy with the level of adjustments to get to even a 75% resemblance to previous renders.
Regarding the iRay and "shouldn't have updated"... first, yes, part of this can be pinned on Daz for not providing some fix mechanism or giving PAs relying on ghost lights more warning to get products updated in time for the release. But they also likely have their hands tied in terms of releases with regards to what nVidia thinks should be the engine iteration bundled and what Daz is obligated to do by the license regarding that decision... and yes, they likely considered the mechanism relied upon for ghost lights to be an actual bug to be squashed instead of an undocumented feature to allow to be exploited, or at least particulars of the way it was relied on prior to this update.
Perhaps I should not have used the term "fireflies" in my post because even though they look like those they are in fact not -- "regular" fireflies can be filtered out (usually by adding render time), these cannot.
I believe I explained it better after some thinking in DAZ Studio Beta thread:
One part of the problem is that 1000000000 kcd/m^2 luminance is just two orders of magnitude below the numerical limit for luminance value -- i.e. if you add two zeros to get the equivalent of DAZ 4.16 10000 kcd/m^2 ghost light luminance, the resulting value of 1.0e+11 (which is perfectly capable of being represented in double-precision floating point) will get clamped to 99999997952.0 implying that between the value you entered and the value shown there is some operation involving single-precision floating point which is responsible for the value truncation.
Furthermore, when you are adding/subtracting/multiplying/dividing such large numbers to/with very small numbers (think much lower luminosity of overall scene light + extremely high luminosity from ghost light kit), numerical errors start accumulating due to the nature of IEEE754 floating point number format -- it can either represent small numbers with a lot of decimal places, or it can represent large numbers with almost no decimal places, but mixing those two kinds of values in the same formula results in numerical errors hence the (in this particular case unavoidable) "fireflies".
After posting that I also tested with some of my previously created well lit scenes and even there ghost lights now result in those white dots which simply cannot be filtered out so my statement about this change affecting only low light scenes was incorrect -- it affects all scenes where a ghost light is in camera's field of view.
First thought I had when I realized that is that maybe if we reduce the exposure value and dial down the ghost light luminosity back to 100 kcd/m^2 the white dots would disappear, but surprisingly they persist and they show up in the Iray preview where the ghost light is long before you dial in the amount of light needed to light the scene which means that there probably is no way of working around them.
thanks so much for working on an update, KA!
i hope you will leave the existing ghost lights as they are. they're key lighting components of almost every scene i've put together since the first set was released.
i'm not super excited about 'upgrades' that make my previous work or workflow unusable, so i've stopped upgrading my studio public release. if i want to play with the new toys, i fire up the latest beta. usually not for long...though that may change when you've made ghostlighting a viable option again.
:)
j
I'm in the same boat here as most people on this thread--a ton of my work is done using KA's Ghost Lights, so much so that I can't remember the last time I used Daz's own Lights for a scene. I'm going to have to roll back my DAZ install to the previous version and wait it out to see if KA has a fix released. Regarding a roll-back, I hate to ask because I'm afraid the answer won't be easy but here goes: is there a simple (one, two-click) method to roll back a DAZ install to the prior version? Or at least a relevant thread that someone might have bookmarked? Thanks in advance.
@KindredArts Hello. Once you've patched your ghost light assets, do you expect old scenes to still render OK in Daz 4.20?
@sentientblob The only way to rollback is if you have saved .dsx and .zip files from DIM download folder before downloading and updating to new version. There is no other way to download older version of DAZ Studio except having a backup of the installation files or opening a ticket, requesting to be provided with download link by DAZ support, and hoping they will want to help.
I wanted to share with you what I found in my testing of Ghost Lights in DS 4.2. I created a scene with a single G8M figure. The G8M figure stands opposite a plane with a Polished Aluminum shader applied to the surface. The camera view includes figure head, reflective surface and a Ghost Light. I used an IGLK Vertical Ghost Light scaled down to 150% and pointing at the G8M figure head.
For the first image, after applying IGLK Ghost Setup, I set the luminance value to 1000000000. No changes to opacity or other surface parameters. As you can see, the Ghost Light illuminates but there are lots of fireflies.
For the second image, after applying IGLK Ghost Setup, I ran the jag11 script. I set the opacity to value to 1.0 and left the luminance at default value 100.0. As you can see, the Ghost Light object illuminates, there are no fireflies, but the mesh shows up in the reflective surface (as KindredArts has mentioned in the orginal post on this thread). For those who will rely on this method alone, there will likely be a "what gives" moment when the render picks up the mesh in a reflective surface (e.g. a shiny coffee pot, a door handle, a car door, a window, a mirror, etc., etc. etc.). Per a suggestion by barbult, for those using emissive objects other than Ghost Lights (could be lots and lots included with propsets sold in the DAZ store), you may need to check to insure that the following are set: "opacity to 1 and refraction index to 1 and the refraction weight to 1".
For the third image, after applying IGLK Ghost Setup, I ran the jag11 script and I set the luminance value to 1000000000. I left the opacity at default value 0.000001. As you can see, the Ghost Light object illuminates, there are no fireflies and the mesh does not show up in the reflective surface.
I have also tested these methods on other "ghosted" emissive objects. Same result.
In my view, the key here for those of us who wish to re-use the scenes we have spent so many hours creating lighting for, is calculating the value that we need to use for luminance. One can start by dividing by the opacity or simply adding zeros until the object provides sufficient illumination, but it's just trial-and-error without some empirical method to calculate the new value based on the current value and the units type.
I've said this before and I will say it again and again: I believe the proper solution to this problem is to build a fix into DS (using new parameter(s)). I should be able to properly render any of my existing Iray scenes without spending any extra time and effort re-building my lighting -or- spending any additional money. I fully understand that DAZ places the blame on nVidia. However, I cannot understand how DAZ can think it is okay just to pass this problem along to the rest of us. As for me, I intend to submit a ticket and request a rollback version of DS.
Yikes, I was afraid of that. Thank you for your answer.
4.20(.0.2) - version numbers are not decimals, the trailing zeroes count.
I've been having firefly problems in every render since 4.15 was released. I've not been able to solve it. So I've been removing fireflies post-render.
Sounds like a lot of work. With the denoiser you may lose some detail but it might also be a worthwhile trade-off in order to lose the fireflies during the render (vs. post-processing).
Right, got it. I believe there never was a 4.2. If I recall correctly (iffy), they went from 4.0 to 4.5
I can understand why one would feel this way. But Ghost Lights were released back in 2016. This product is going on 6 years old. The other Ghost Light products are a few years old, too It is not realistic to expect to get 100% free product support for eternity, especially from 3rd party vendors. What if the vendor is retired, or is at a different point in their lives? 6 years is a long time, eternity is even longer. <.<
If the product was still new, then yes, I would expect a free update, absolutely. Or perhaps if it was a Daz Original. But neither of these is the case. If the product is updated for free, then that is fantastic, but if ends up being a new product with perhaps new functionality, then IMO that is ok as well if there is a discount tied to it. It depends on just how much work has to be done to properly update the product.
While I agree with the thrust of your argument, KA has stated that they intend to update the ghost light products to work in the current versions, and has pulled them from the store pending update.
It is not Ghost Lights that is root of problem. And it's not just Ghost Lights that are affected. It's any and all emissive objects that are "ghosted". I use them continuously everyday. Am I the only one? There is no way to replace these in the store. I absolutely cringe at all the unplanned work that likely to result from this. Some of us have to produce images and not content for the DAZ store.
I pay dearly for DS every time I purchase content, I want it to work correctly regardless of who is at fault for an issue. Many of us have lots and lots of content that was created well before Iray (DAZ sell this stuff everyday in the store). By and large, it still works and often without any change to the textures.
I believe the correct solution is not a piecemeal change in the objects we all create and/or use. The solution should be built into DS so that we can continue using our existing lighting. Most of us know full well how critical lighting is in producing good renders. Hence, most of us spend considerable time in getting just the right light. All that work has to be re-done? I rarely light a new scene from scratch. I load and re-use exising lighting schemes just about every time I start a new scene. Sometime, I load an existing scene, replace some content in the scene, and then render. Not anymore. Major disruption to my workflow. What is the upside to end-users?
I would gladly pay $10-20 for a solution that allows me to load and correctly render my existing scenes without having to re-build my lighting. But I am simply not going to buy a new version of Ghost Lights in order to solve the problem introduced in DS 4.20. Even if I did purchase revised sets, I would still have to replace my existing Ghost Lights (in my lighting schemes) with the new ones. That, in itself, is not a trivial matter. And it may not produce identical results (we shall see).
So, I just wasted three days in finding a workaround that gets me close. If it's a choice between using a new version of Ghost Lights vs. implementing the workaround, I am going to go with the workaround every time. I am going to have to re-build my lighting either way.
No one is suggesting that KindredArts stop creating new Ghost Light sets, regardless of changes to DS. I have purchased two additional sets after the original was released.
I'm with you on the version updates...though for other reasons than ghost lights. I always save my old version of DS for just that reason. I updated to 4.20 last night...not impressed. So I'll likely be using 4.15 for the forseeable future until I can figure out how to make my workflow work in 4.20.
As much as I understand the frustration, I have to admit, that I do like the new way ghost lights are handled. It is infact more physical accurate. I'd use these ghost lights with window glass material, for it simulates the effect of light spreading in the glass quite nicley. For this an opacity level of 0.005 looks right to me.
johndoe_36eb90b0,
I found that by applying the jag11 script (in addition to using a large luminosity value) this problem can be worked around. Either of these solutions used separately will create unwanted side-effects. The question now is: In order to recover the same lighting we spent so much time in tweaking prior to 4.20, is there a way to calculate a new optimum luminance value based on the current value (used prior to 4.20) and the luminance units? Thank you in advance for any help you can provide.
Masterstroke, that's great. However, I contend that in order to properly serve it's customers, DAZ should build into DS a solution that allows us to choose whether to use our existing lighting schemes, unchanged, or to utilize the nVidia mod. If not, someone please explain to me how it is okay for DAZ to simply pass this problem on down to the PAs and end-users. I have spent more years in software development and software testing than I care to count. We would never, ever have considered doing such thing.
I'm not sure, if DAZ is to blame here. After all, we are talking about IRAY, which is Nvidea's software. They are in charge here.
I don't know, if it is possible for DAZ at all, to introduce a button, in order to toggle between those two shader features.