x

Search in
Sort by:

Question Status:

Search help

  • Simple searches use one or more words. Separate the words with spaces (cat dog) to search cat,dog or both. Separate the words with plus signs (cat +dog) to search for items that may contain cat but must contain dog.
  • You can further refine your search on the search results page, where you can search by keywords, author, topic. These can be combined with each other. Examples
    • cat dog --matches anything with cat,dog or both
    • cat +dog --searches for cat +dog where dog is a mandatory term
    • cat -dog -- searches for cat excluding any result containing dog
    • [cats] —will restrict your search to results with topic named "cats"
    • [cats] [dogs] —will restrict your search to results with both topics, "cats", and "dogs"

Lighting and Reflection questions

I have gone through all lighting/decal/etc documentation and most features and have following questions/looking for confirmation on theories:

A - Reflection Actors

  1. Is there any impact on fps or rebuild times having a great number of reflection capture actors? Or filesize (given it has to capture all those cubemaps)? UDN says that there is an impact if there are lots of capture actors affecting a pixel, thus overlapping should be kept to a minimum?

  2. If so, how much overlapping would be too much? Is there any way of seeing which areas of the level have no reflections, and which have too many? Similar to light complexity view.

  3. It says on UDN that there is a maximum of 341 reflection captures possible. Does this mean a maximum of 341 capture actors in a single level, even if they are not close to each other, or what does the limit mean exactly?

B - Lighting

  1. Am I correct that an ideal lighting setup in an indoor level would consist of just one or two Stationary lights per room/hallway (and only for the most powerful light sources), and everything else made up of normal Static lights? Is this how you approach your content? A few rare Stationary lights, rest Static and perhaps a few Stationary ones with shadow casting disabled where possible?

  2. I have seams between my meshes, is this a known limitation/problem or something I could have done better? See image. This is with production quality + 64 to 256 lightmaps. Each square is one modular wall mesh, the lighting makes the pieces not seamless.

alt text

C - Decals

  1. So the number of decals in a scene no longer has an impact? It does not add drawcalls? Does it render all of them in one go now? My tests are a bit inconclusive, looking for confirmation if this is indeed the case.

D - Particles

  1. Is there any chance we can have this ../UE4/Engine/Extras/VectorFieldExporter/Maya2012_x64/Shelves/shelf_ue4_FX.mel included in our version? Also do you happen to have a Max version?

Thanks.

Minor bug by the way (found it too minor to make a report for), the console suggests I type "stat d3d11d3d11" which is the wrong command.

Product Version: Not Selected
Tags:
lightingseams.jpg (99.5 kB)
more ▼

asked Mar 11 '14 at 02:57 AM in Using UE4

avatar image

ue4-archive ♦♦ STAFF
50k 3671 2000 9125

(comments are locked)
10|2000 characters needed characters left
Viewable by all users

2 answers: sort voted first

Is there any impact on fps or rebuild times having a great number of reflection capture actors?

The amount of overdraw of the reflection captures affects GPU time, similar to particles. Overdraw happens inside the influence radius. We're going to add a viewmode to visualize this. The number of reflection captures affects load time and how much video memory is used. In the future we are going to save the reflection captures to disk so they won't get recaptured on every load.

It says on UDN that there is a maximum of 341 reflection captures possible. Does this mean a maximum of 341 capture actors in a single level, even if they are not close to each other, or what does the limit mean exactly?

It means a maximum of 341 in a given world at once. Reflection captures currently don't work correctly with streaming levels, this needs to be fixed.

Am I correct that an ideal lighting setup in an indoor level would consist of just one or two Stationary lights per room/hallway (and only for the most powerful light sources), and everything else made up of normal Static lights?

Currently we build levels with all Stationary lights (except where needed movable for gameplay). Only the most important lights have bCastDynamicShadow enabled, all the rest have that disabled so that they don't cost much. Static lights have very poor quality on characters so we don't use them at all.

This method needs to be improved though, because it's very difficult for level designers to tell where all their shadow cost is coming from, and to manage this character lighting setup via bCastDynamicShadow settings. It's easy to explode your shadow cost by just throwing in some overlapping stationary lights and a bunch of large dynamic objects.

I have seams between my meshes, is this a known limitation/problem or something I could have done better?

This is a result of the way Lightmass calculates indirect lighting right now which needs to be improved. I'm not aware of any way you can work around it in content, unless lowering the StaticLightingLevelScale helps (that makes builds longer though).

So the number of decals in a scene no longer has an impact? It does not add drawcalls? Does it render all of them in one go now?

They do have an impact, its just much less than the forward decals in UE3. Basically they mainly cost in GPU time due to overdraw, just like lights, reflection captures and particles. This is because they are rendered deferred. Note that these deferred decals have some serious restrictions: they don't work on dynamic objects, and they don't affect indirect lighting (although this last one may be fixed).

I will fwd to someone else for the exporter question.

more ▼

answered Mar 11 '14 at 02:57 AM

avatar image

ue4-archive ♦♦ STAFF
50k 3671 2000 9125

avatar image ue4-archive ♦♦ STAFF Mar 11 '14 at 02:57 AM

Great thanks a lot Daniel!

Can you give me any kind of number how much overlapping is too much? This probably depends on material complexity and so on, but is there any kind of number that usually tends to be ok? Is it along the lines of just 3 or 4 reflection actors affecting the same pixel, or more about 20 or so? Just a rough indication to give me a guideline.

avatar image ue4-archive ♦♦ STAFF Mar 11 '14 at 02:57 AM

There's no limit, it just depends on how much GPU time you can afford. 3-4 is probably the lowest you can do with a reasonable quality setup, and that's what I would recommend. If you want to measure the actual impact, the 'profilegpu' command will measure everything on the GPU and the 'ReflectionEnvironmentGather' time is how much the overdraw cost.

avatar image ue4-archive ♦♦ STAFF Mar 11 '14 at 02:57 AM +

Are there any other reasons not to use Static lights? No specular aside? I am thinking for use in far away scenery.

In UE3 I used light channels to include meshes that were to be affected by a moveable light. Any chance on something similar here? As it could help excluding meshes from certain lights. If you got two floors, a light on floor 1 would also affect meshes on floor 2 performance wise, even while you wouldn't be able to see that all. That would also make it far easier to turn off shadow casting on some lights, the lights would not shine through the ceiling/floor then.

(comments are locked)
10|2000 characters needed characters left
Viewable by all users

Is there any chance we can have this ../UE4/Engine/Extras/VectorFieldExporter/Maya2012_x64/Shelves/shelf_ue4_FX.mel included in our version?

We don’t have this available for beta users. We are currently looking into what extras we want to include for Rocket betas.

Also do you happen to have a Max version?

Unfortunately there currently isn't as Max does not have a built-in fluid simulation engine. Some licensees have already ported the exporter to their in house tools as the code is pretty straightforward and the .fga is in human readable ASCII format. You could do the same thing for Fume FX or for other plugins should you want to.

more ▼

answered Mar 11 '14 at 02:57 AM

avatar image

ue4-archive ♦♦ STAFF
50k 3671 2000 9125

(comments are locked)
10|2000 characters needed characters left
Viewable by all users
Your answer
toggle preview:

Up to 5 attachments (including images) can be used with a maximum of 5.2 MB each and 5.2 MB total.

Follow this question

Once you sign in you will be able to subscribe for any updates here

Answers to this question