I was just noticing in a lot of the Epic Games examples the Lightmass indirect bounces are set pretty low, like 3 to 7. In re-lightmapping the scenes setting it to 100 bounces seems to increase the softness and realism of things… and according to the documentation and with UE4 4.9 100 bounces doesn’t affect speed much.
Will there be any issues during runtime? Since the 100 bounces are mapped onto the lightmap (a raster image) I don’t think whether 3, 7, 50 or 100 bounces matter.
It doesn’t take very long. I usually have it set to 100 bounces. As it says in the documentation, each additional bounce takes less time than the last, so it ends up adding very little time to the builds.
That’s my experience too. 10 bounce vs 100 bounce is really not a huge difference in time, but (to me) a huge difference in quality.
I’m still learning UE4 but with the Learn/Marketplace assets setting the scale to 1, 100 bounce, quality 2.5, smoothing 2.5 and AO baking on, nice stuff and with UE4 4.9 the bake times are within an hour to several hours depending on the size of the scene. Not too bad, IMO, for the quality you get.
There’s no runtime impact to the number of bounces since the result is stored in the lightmap.
100 bounces will have a small impact on build time compared to 10, as it’s just a matter of letting indirect photons bounce more times and those are a small part of the overall build time.
does increasing photon amount in lightmass.ini cause issues?
ive gone in to the ini file and changed a fairbit like photon amount, changed 350 to 600 etc.i also tweaked the production quality settings increasing them I think. my build times are a lot longer and quality does seem better but that could be me improving materials etc whilst editing the map…ive took my own photos around my flat and used them for the materials.wall,sofa,vase,bowl,carpet,floor,window view.
I changed the spot lights to indirect bounce card ones like arch vis people do and tweaked the directional light.
ive maxed out/increased most settings just to see whats possible and got to say results are very impressive considering iam noob :}, lightmass scale 1,set static meshes to 1024, bounces 100,quality 10, smoothness 0.8.enviroment intensity 1.5,indirect intensity 1.5.
tweaked post process and all materials, wall is 3 texture samples of diff rooms in my flat , in materials I used muliplyadd nodes taking red,blue channels …then combining them , no idea if does anything but I like tweaking.the floor iam most pleased with and ive no idea what changes got rid of the nasty specular grains.
heres a screenshot ,really doesn’t do the room justice, as you fly around its awesome especially in the bright light near the window/sofa.sadly I deleted the project by mistake so all I have is this screen shot I took quickly to test the screenshot feature.framerate is great too, solid 70-119fps+ ,9-17 ms and doesn’t really take a hit when particles or characters are added. had a woman I created in fuse dancing round room with particles bouncing about using the distance field setting.i know my gpu is good 980ti but even so the only settings ive found that kill fps is temporal AA set to 200+ or bokeh depth of field scale set high whilst running at 1440p.
this screen shot is without lightmass.ini tweaks in a empty map. but shows the type of madness I was doing with particles and is a kool screensaver image.:}
hoping I can improve the look more in future as I learn.thanks for reading :}
how does changing the DPI of textures effect ingame materials, the textures I created I did them at 4096 resolution and 500 dpi jpegs. this makes them a lot smaller files and ingame scale but does it change how they are displayed ? or would 72 dpi and 4096 .tga/png get better results.
DPI is a measurement used for printing ( dots per inches ).
You can interpret a pixel as a dot, therefore images have the same amount of information when they have 4096 pixels in width and height - the measurement of x * Inches does not exist for Unreal Engine since your texture scale is defined by the UV’s it is laid out on.
What will make a difference is image compression, a jpeg will most definetly have compression artifacts that will visually reduce the quality of the image while .tga or .png files won’t have this problem as much. Unreal Engine internally transforms the images to another format, therefore taking the higher quality source image is always the better option. The transformed image won’t have a different size depending on what source image you used, however the visual artifacts from image compression can remain.
(Use .tga )
Cool stuff. From what I’ve read on the ArchiViz section tweaking the Lightmass.ini gives great results (if you know what you’re doing) and I haven’t read about any runtime issues.
thanks for the reply ,interesting that unreal converts to its own format.the main reason I tried jpeg was because of the file size .a 4096 .png/.tga are huge files up to 82mb which I thought would increase the project size once built and iam keen to keep my projects small so friends can download them + my internet sucks so any uploads will be slow.
definitely helpful to know how unreal or game engines in general compress images.
there’s a decent explanation of the core principle in Block Truncation Coding - Wikipedia
