UE4.11 preview 1 - Rendering Test

This is my test using Realistic Rendering demo from Epic. Using default settings in BaseLightmass.ini (no tweaking at all), World Settings Lightmass, and Matinee settings. The light building time was 12 minutes, without Lightmass portal.

The very same project took 25 mins to build the lighting in UE4.9.2, using default settings as well for .ini file and Lightmass setting. The light building quality was set to Production.

The only thing that I had to change was the SM_Background’s material, from Translucent to Opaque, otherwise all the buildings outside will be invisible. I think UE 4.11 has brighter lighting than all of the previous versions of UE4.

This video was recorded using Matinee at 1280x720 60fps. If you watch it in HD, the video will playback at 60fps.

UE 4.11 preview 1 still has unstable video (AVI) recording though (crashed several times), so I had to record it as a series of PNG files and then creating the video using Vegas Pro.

I think some comparisons between 4.11 with portals and without portals might be more interesting, I’m going to try that with the Koola scene.

Yeah I was thinking about that too. But I haven’t got much of free time yet. This video was created like few hours after UE 4.11 preview 1 was released, but I just had the opportunity to upload it today.

@ZacD if possible, do not change the baselightmass.ini file at all.

IIRC Realistic Rendering was setup with a bunch of spotlights to emulate the sky lighting instead of an actual sky light, so it won’t get much benefit from portals. Ironically it was done that way because skylight quality was lacking before 4.11 + portals.

Realistic rendering will still get the 2x build speed improvement from Embree though, as your results showed.

If you want to see the impact of portals really well, delete all the other lights, place a skylight and compare 4.10 vs 4.11 with portals.

Yes. Agree. The Realistic Rendering project do have a bunch of spotlights in front of glass door/window to emulate sky lighting. I managed to steal some time and creating a second test of Realistic Rendering project. So here’s the video:

Things that changed in this video:

  • Adding Lightmass Portal
  • Adding Skylight, bumping up the intensity value from 1 to 4
  • Directional Light is disabled
  • Spotlights in front of glass door are disabled
  • Indirect Lighting Bounces changed from 7 to 30
  • Static Lighting Scale changed from 1 to 3
  • All other values are at their default that come with the project file.
  • No tweaking in Baselightmass.ini file at all.
  • Production Quality Lighting

The light building time is only 10 minutes, much faster than the first test.

Can I ask how one adds a 'lightmass portal"?


You can find it in ‘All Classes’ mode tab. Next to Lightmass Importance.

10min? that’s cool. Thanks for this test. I was about to do the same today.

You’re welcome.

I think the reason why the light building time is so fast is because of Embree and also I’m upping the Static Lighting Scale value instead of lowering it. If you lowering the value of Indirect Lighting Bounces to, say 7 like the default value for this project, the building time should be less than 10 minutes I guess.

A lot of the detail shadows have been smoothed away due to that though.

I always curious about the difference between Indirect Lighting Quality 10 and Indirect Lighting Quality 1. So I took Xoio’s Berlin Flat map from marketplace and making comparison video. Here it is:

Using ILQ 10 build time was 3 hours 16 minutes :stuck_out_tongue: while ILQ 1 took only 26 minutes.

As usual, several changes had to be make:

  • spotlights and reflectors outside the house are disabled
  • adding lightmass portal in front of each window
  • adding BP_SKY
  • changing light map size to 512 for ceiling, floor, and walls.
  • changing all BSPs light map size to 8
  • global post processing volume is disabled, using post process effect from each camera instead

The Lightmass setting as follows:

  • Static Lighting Level Scale 1
  • Num Indirect Lighting Bounces 64
  • Indirect Lighting Quality 10 and 1

Other settings are at their default values.

For me the difference is not much. Yes, the ILQ 1 scene is darker than ILQ 10, but honestly I failed to see big difference though, except for the light building time :D. Maybe in the future I would use value between 1-3 for Indirect Lighting Quality to save some time.

Thats a cool comparison, and youre right as in most cases you wont see a big difference, but what I mainly use the higher indirect lighting values for is to solve lightmap transitions from one surface to another.
I have attached a picture to demonstrate it. In this case I had a lighting seam between 2 floor meshes, and by using a higher Indirect Lighting value I was able to smooth this out.

Ahhh I see… Thanks for the info, will keep that in mind :slight_smile:

Quality has diminishing returns, so if you jack it up in a situation where the quality is already good, you won’t notice much difference. However if you setup a deep cave with only a skylight (difficult case to solve with quality) then you will start noticing a much bigger difference.

sandermer’s example shows nicely how the default smoothing covers over quite a few noise issues, but they still show up at object seams. But when both side of the seam converge on the correct result, the seam disappears. Hopefully one day we can have smoothing across these seams and then you won’t have to rely on a long build just to get rid of the seams.

tupikp, why specifically 64 bounces in your scene?

It’s worth noting, that it’s probably quicker to merge meshes to avoid seams like this, than increasing your baking time. Or designing your textures/meshes in ways that seams like this wouldn’t be noticeable. Like if that seam was at the seam between two boards on a wood floor texture.

Programmer’s habit I guess. I tend to automatically pick up power of 2 numbers, such as 2, 4, 16, 32, etc. :smiley:
bathroom5 by simfactor, on Flickr

Out of curiosity I built the lighting of the same scene (picture above, without changing any parameters at all) three times. I was under assumption that the build time would be the same through out the test. However, the result is really really unexpected. Here it is:

First build time : 14:42 minutes
Second build time : 15:28 minutes
Third build time : 22:18 minutes

This test was conducted using UE4.11 preview 3 and no parameters/values were changed between the test.

So the first question that came up to my mind was: Is this a bug?

I also experienced this, building light in UE4.11 preview 3 take a lot more time than preview 1 …

From my experience I always turn off my computer and restart it after about a minute to make sure it is completely fresh and has all available power to render. Did you try that as sometimes running lots of apps before rendering can slow things down. I’m not a computer nerd but I have noticed this.