Hi
I have a problem to build lights in my project file. I have quite big yacht project - 145m long ship. I have set up lightmap resolution by object size and detail which i need for GI. The resolution is then from 64 to 4096 px. Unfortunately I have hit the wall of my computer memory - 64GB. It helped me to decrease some lightmaps from 4096 to 2048 px, but then I have not sharp shadows and GI as I need. This method keeps memory usage on 62.1 GB and CPU is used from 85% whic is nice. But when I hit the wall of my memory, then CPU is used only on 4-5%… Model of the ship is inside of LightmassImportanceVolume box. There are no other object out of this box.
Is there some trick to save memory and keep the resolution of lightmap as big as possible? I would like to create a photorealistic rendered model of yacht.
Also, is there a way to rerender lightmap only for new imported models? - beter then volumetric light cache information?
Thanks .
You can’t trade memory for CPU time, they’re fundamentally different things. I don’t know if lightmaps are occlusion-culled or not. If they’re not, you’re storing ALL of your lightmaps in memory the whole time the level is open, nothing you can do about it. If they are occlusion culled, your framerate will suck because it’s streaming 4K textures in and out of memory all the time.
Honestly, I’d be very surprised if you need a 4K Lightmap for anything.
Building lightmaps is a very memory intensive process, especially with LM as big as you want and there is no way around. You either have to go for a lower resolution lightmap or get more RAM for your PC. Not the best I know but why not try and use a fully dynamic lighting setup? Here are some links to get you started in the right direction.
This should show you how to setup some really nice dynamic lighting and shadowing. Once you have that that way you want, I would look into adjusting the post processing to adjust brightness and add the finishing touches.
Hope it helps and post some pics so we can see your progress.
Ok, The idea to switch to Ray Traced Distance Field Soft Shadows looked promising, but on some parts of model looked worse then low ress lightmap. I have tried to tune the resolution of distance field but without any better look. This technology work well with solid models, but not with tiny lines or models with a lot of holes and etc.
So I am still on lightmap setup.
I have new problem. I am using static light to get nice area shadows, but on the other site I need to have there some basic dynamic shadows by spinning radars.Spinnnig has been done in blueprint. In my case, there is no shadow. How get there some shadows and keep nice area shadows in lightmaps by static light?
I have already tried almost everything to get the shadows on spining radars but without any succes. I still want to keep nice area shadows on static meshes computed by directional light in Static mobility but also add shadows for two rotating radars. Can static light generate dynamic shaows for moveable meshes? I have tried to create second stationary light but this way seems to me like wrong way.
There has to be a solution. Pleas help.
Change mobility to movable on the static mesh details menu (bottom right menu).
Also you should think about light map resolution like this, a 1080p display is basically 2k x 1k. A 4k x 4k light map has
8 times as many pixels as a 1080p display, that’s why your ram is getting killed. Use the light map resolution density view to make sure most places have a similar texel density.
Set your light source to Stationary if you want to have both dynamic and static shadows. Play around with cascaded shadow maps parameters of the light if dynamic shadows disappear at an unexpected distance. However, i would use fully dynamic lighting(movable directional light) for a boat like that.
hmm, when I use Stationary or Movable light, I get static and dynamic shadows, but without **area shadow function ** Area shadows are defaultly generated in Static mode of light and that is what I want to have. Nice area shadows. On the other hand, that way I can’t create shadows for moveable meshes. Ray Traced Distance Field Soft Shadows created a lot of issues so I have discarded this way also. (Resolution didn’t helped)
There has to be some way to generate dynamic shadows just for some parts of scene but how?
I’m actually astonished that you manage to max out 64Gb. For the largest of the archviz projects I’ve done, I’ve needed 24Gb, and that was with a few 4k light maps, some 2k and lots of lower res lightmaps with pretty high lightmass settings. I would try looking of your lightmap UV sets etc and try to optimize them in order to use smaller lightmaps. Also try dividing some meshes so you don’t need to use those enormous light maps everywhere, but only where visible. It’s really easy to go overboard with the lighmap sizes if you don’t optimize properly.
