Dynamic-only lighting questions
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When I add only a single point light to my scene, and set it to 0 brightness, the scene seems to be lit by a default directional coming from above. Where is this lighting controlled? If I disable the point light, I get no lighting at all (fullbright).
Is there a world ambient color setting somewhere? It looks like I can set a hue in the post process chain in World Properties. But is there an ambient setting anywhere else?
I'm learning about how lighting works in UDK, and would like to attempt a dynamic-only approach, no Lightmass. Partly because I hate waiting for bakes, but also because it seems UDK has enough controls to get a good dynamic result. And I've had good dynamic results in a custom engine that had much less user-adjustable controls.
Is there a world ambient color setting somewhere? It looks like I can set a hue in the post process chain in World Properties. But is there an ambient setting anywhere else?
I'm learning about how lighting works in UDK, and would like to attempt a dynamic-only approach, no Lightmass. Partly because I hate waiting for bakes, but also because it seems UDK has enough controls to get a good dynamic result. And I've had good dynamic results in a custom engine that had much less user-adjustable controls.
Replies
Note there is other stuff set up in the default preset scenes as well. For that reason I usually start with a 100% empty scene.
There is also a flag in World Properties Lightmass - bForceNoPrecomputedLighting if you want to go full dynamic. This removes any rebuild lighting message and so on.
Note that Unreal is a forward renderer and Dynamic Lighting is heavy to render in the engine.
Also you will need to turn on dynamic shadows on your dynamic lights. On a dynamic point or spotlight, set LightShadowMode LightShadow_Normal, and turn on CastDynamicShadows.
All three lights enabled. (SkyLight, DominantDirectionalLight, PointLight)
All three disabled. This makes sense. I would expect either everything to be black, or everything to be fullbright.
DominantDirectionalLight enabled, brightness set to zero. There's a hemisphere light on everything, which I guess is the LightEnvironment?
Thanks for the help both!
i dont think that the light environment should be affecting your environment unless you are using dynamic meshes. obscura is also correct the middle image is in unlit mode.
Im personally not a huge fan of dynamic lighting in unreal. it looks very shiny and not diffused. try adjusting the light source size and its falloff, you can fake some bouncing to a degree
but vertex baked lightmass actually turns some really nice results and vertices bake a lot faster than lightmaps as its the reimport thats pretty slow.
my 3c
http://udn.epicgames.com/Three/ContentBlogArchive.html#Changes%20to%20previewing%20unbuilt%20lighting
Got the stuff in this thread figured out and working ok since week or so ago.
Also got the shadow bias adjusted so there is less artifacts at steep angles. (This one is hidden in the ini files for anyone trying to solve this).
The last thing I noticed while doing some tests was that the specular power didn't seem to do anything. Seems no matter how high or low I put it it always looks to be really high on anything in the level although it looks correct in the material editor. Haven't had time to really dig into it though so not sure exactly what is going on. If anyone has noticed this and knows of a fix that would be great. According to the UDK documentation the deferred lighting should support specular power bu i suspect it might still be a dx11 issue since I haven't noticed this before.
I'll come back with some more once I get a chance to investigate this further.
If you are looking to get the most out of dynamic lighting then let me point you to a post I made in another thread recently about using physically based shading in UDK. http://www.polycount.com/forum/showpost.php?p=1787202&postcount=10
You are a bit limited if you want to take advantage of deferred lighting so anything but Phong shading will use forward rendering even in dx11. I was hoping to be able to get decent results with deferred lighting so I could use it for most of what is on screen and avoid some of the performance Issues with dynamic lights in UDK.
My conclusions so far is that the problem is indeed with the deferred rendring since the problem only happens when all the conditions for deffered lighting is met. If I switch to dx9 the spec power starts working again, same if I use Ipcstr's custom lighting or switch the lighting model to mlm_shprt.
I also notice now that the specular highlight has some quiet bad banding when you zoom in close. As you can see in the attached picture the dx11 renderer is also adding some artifacts at the edges when I use Ipcstr custom lighting.
The banding on the Phong specular highlight got less noticable when I switch on High Quality G Buffers but the other problems remain. (Picture is without this enabled)
I guess the question is if deferred rendering can't do better or if something is wrong on my end.
If I can't resolve this I'll probaly go back to dx9 and lightmas with only key lights dynamic, although it would have been nice to ditch the light maps.
or,
DX9 - crappy dynamic shadows and 150 fps...
Yeah so hard to choose :P But at least we are going to get proper dynamic lighting in UE4.