Hi all,
I have to do a timelapse for an architectural interior project, for that I use a dynamic sunlight with Ray Traced Distance Field Soft Shadows. I have no lightmass calculation.
How can I boost my rendering quality to get the same quality we can get with Lightmass system?
Tks for your answers!
For an interior, impossible. There is no indirect illumination with dynamic lights. Even if you add a movable skylight it won’t look good and you won’t get any soft shadows. What level of realism do you need?
Even advanced solutions like VXGI (dynamic global illumination) does not give good enough results for arch-viz!
Best option for dynamic lighting would be VXGI, you can turn up the quality for it so if you don’t care about real-time then it can look pretty good, better than the default dynamic lighting though not quite as good as baked lighting.
My suggestion is to make it like Rafareis123 did in his last apartment scene, bake 2 or 3 versions of your scene. One for day, evening and night. I don’t think it’s really necessary to see the transition between those and you’ll get 3 high quality version instead of something that looks not-so-good.
tks you all for you answers!
heartlessphil : Unfortunateliy I need the transition with the sun movement.
darthviper107 : Yes, I don’t care about real-time, I have to take a look to the VXGI, I never heard about it 
Ps: to install VXGI I must use the source version of unreal? is it compatible with the 4.9 version?
I think so, it’s on the nivdia gameworks github. You need to download the whole editor source and compile it with visual studio.
Here’s the link. If you can’t see it it’s because you need to create an account : https://github.com/NvPhysX/UnrealEngine/tree/VXGI-4.9
This is the kind of quality you can expect, except now it’s possible to have multi bounces of G.I but you need a good pc. If you wanna make a video of it, prepare to have some artifacts.
yes I am actually trying to install this version https://github.com/GalaxyMan2015/UnrealEngine/tree/4.9.1_NVIDIA_Techs
Is there another methode to achieve good result like lighmass quality ? I haven’t seen yet an architectural interior project with timelapse and nice result.
I made some tests with volume propagation but the quality is not enough…
After many test with Light Propagation Volumes and VXGI. I think that the best way to have nice rendering quality is using lightmass.
My problem is that my sun is movable. So according to you what is the best way to achieve nice rendering with a movable sun? can I combine this with a lightmass. I feel a bit lost 
Thank you for helping me.
Like we said, there is no best way… directional light (sun) set to dynamic does not give global illumination. Only direct light. It would be fine for a vast open field like the kite demo. But in a house where real lighting bounce everywhere, it’s impossible to use dynamic dir light and expect good results. Unless you want to start faking it with point lights and stuff but then again, you’ll only get harsh dark shadows. During the night it would be less noticeable but at noon, meh.
You can use a movable skylight to soften the harsh shadows, with a very very low intensity, because it will affect the whole scene regardless of geometry. But objects that won’t be under lit directly by the sun won’t have any shadows at all and mean appear to float on your floor.
ok thank you hearlessphil 
I have to make new tests…
my try with vxgi
Looks pretty good. And the thing about Archviz stuff, you can turn up the VXGI quality really high since it will still render extremely fast even if it has to take twice as long as it would for realtime.
I hate VXGI because of these light leaks/splotches everywhere…
but its very fast
and usefull for exterior projects without building light
Yea for exterior sure! For interior only if you don’t need realistic imagery.