I’ve also experienced this, but it doesn’t always work. But it got rid of 98% of the cases.
FIXED!!!
I was using Nvidia old driver when I had this error. Please update new driver and everything will work smoothly. Thanks Situx.
In case you have this error, update driver.
Nothing more than a big thank you for the GPULightmass !!
Harder, Better, Faster Stronger !!!
Any idea how to fix the blocky shadows where geo meets up?
As I know and you can read on the 1st page of this topic, this new alg. of baking needs more Light Map resolution (is resolution sensitive). For a single bottom cushion you have here ( I hope that you have split whole couch on parts) you should use sth min 256 and better if 512px of resolution ( for that single part). I have checked it and when I have some ‘stairs-like’ shadow then just double the resolution and I have it smooth enough. GPU Lightmap bake is fast enough to handle well 512px+ LM resolutions w/o waiting too much longer as it was with the CPU bake.
@Loushouang - emissive materials for static meshes do not emit any light for bake. ie. when I use power of 1 (material unitless emission power ) and it is enough for the brightness effect when camera looks at it, the nthe effect on surrounding object is NONE. Even when I crank up the value for Emission multiplier in static mesh parameters (i.e. from default 1 to 500). No effect at all.
Do I do sth wrong or it does not work correctly with GPUlm for 4.20.3 ?
@Loushouang - ETA & ligthmap bake statistics.
I have to say that ETA is computed wrong. Cause when I have many objects with many LODs then the GPU computation time for bake at single pass is much shorter that CPU mipmap generation (or whatever CPU is doing after every single pass of GPU computation ). And your ETA is based only on GPU work (as I have observed).
So notice dear community that even if somebody has very powerful GPU card then strong (very, very multicore setup) for CPU is strongly recommend when scene has objects with many LODs (many LODs for very complex vertex structures 60-100k+ for LOD0).
Unfortunately this kind of bake time computation (or summarization - dunno how to describe that) based only on GPU work gives wired results in statistics.
Statistics are very helpful sometimes when we need to check what was baked so long for example.
And they contain very insanely low bake times (?!) according to the real duration of whole baking process.
This is not something with high priority on TODO list. But maybe it could be fixed when you will have nothing to improve with your fantastic GPU bakery 
for which I THANK YOU VERY MUCH MASTER Loushouang !
- I would like to ask if I your BATCH manager for Lightmass I will download every new update of GPU Lightmas automatically to my local machine when you upload it to your distribution place ?
Technically possible, but any future update will need to have its hashes calculated to properly detect what version you are running.
However, It is not intended that way. The installer is meant to make it easy for non-savy users, or lazy ones like me who either has to make CPU bakes now and then, or install GPU in many computers. Theoretically, you can “clone” the installer’s repository, then each time I upload a change you can pull the changes, but not automagically.
If there is enough interest I may look onto something like that, but would depend on the use case and the free time I have available. Also my guess is this won’t take long to get integrated into the engine (this is amazing tech). At this point anyway I don’t believe there would be much more updates before 4.21 starts previewing, at which point we’ll probably need another GPU heavy update, including the batch file, or even (hopefully) see some GPU baking integrated into the engine which will make the installer obsolete.
Also, note the “blocks” match your Lightmap UVs texels. If you increase the resolution it doesn’t fade away, you just have a less noticeable effect. For perfect fit, you could just re-author the sofa lightmap UVs to match/align the final position of the cushions, removing the jagged shadows completely, therefore keeping resolutions at bay. Keep in mind that lightmap resolution affects memory footprint of the object, and if you go over 512 you may see exponentially larger disk space and memory usage. Specially, if you want to keep this to a manageable mobile or VR project that can run in anything lower than a GTX 1080, this would be something to consider. Not something most projects care about as normally hardware is pretty beefy on the workstations, but something to keep in mind anyway, specially if it has to be shipped away to a customer.
hmmmm… sometimes changing UV for lightmap = serious re-topology or at least fixing the model.
Because I use Blender for modelling I have to fix models not made by myself very often ( even those bought ).
But this consumes a lot of time to fix the blocky shadows.
So increasing the resolution can save your project and save your precious time.
Maybe better approach than doing hard UV labour for the light maps is to give to the GPU lightmass optional algorithm to have more blurred shadows for whole scene, for some objects or for some conditions ?
I do not know. But I know that most of us want to be more an artist than a technician of bad models UV fixation.
You need to turn on the checkbox in the staticmesh to allow emissive light to contribute to the lighting calculation.
Anyone here who tried GPU lightmass on RTX card?
I just got 2080ti today and my computer crashes after I start the build.
Just to be sure: you did a fresh install of the Nvidia driver?
I have the same problem with 2080ti.
And I reinstalled everything. Drivers and UE4 too. It always crashes.
My only workaround to continue working now is to exclude my PC from building the light in swarm agent and using other PCs on the network.
Hi @MaximumDup
Thanks for the video helping to setup the VXGI 4.19.2 with the GPULightmass. I wonder if there is a way to use VXGI and GPULightmass at the same time in one sence.
Hi Guys, i Have same problem here… the first One is CPU Bake. The second One is GPU Bake. I dont Know why is So Black . what did i do is Migrate all Things ( CPU Project ) to GPU Projet. But is so dark. anybody know i solve it ?
Is anyone else experiencing black areas that affect only dynamic objects after building Volumetric Lightmap? Like this: https://answers.unrealengine.com/questions/834814/volumetric-lightmap-problem-black-box-areas-on-mov.html?sort=oldest
I think I had this since before using GPULightmass, but I figured with so many people working with lighting, I might not be the only one experiencing this.
Happens to me all the time, but it’s just a bug of lightmaps not loading (invisible) after bake. You can still save as it’s just that the textures are not loading. It’s quickly solved by re-loading the level (I use streaming lighting levels), or making the persistent level hidden and visible again (which reloads the level).