Thank you so much
WIKI Guide: Swarm Agent Troubleshooting and Tips!
Swarm Agent Troubleshooting and Tips Guide
Recently I finished a basic troubleshooting guide for Swarm Agent. If you’re not familiar with it this is the application often hidden behind the curtain when you build lighting for your scene. Lightmass in UE4 will export information to Swarm Agent to process and do all the heavy lifting.
Unfortunately, there isn’t a whole lot of information out there about using Swarm Agent and troubleshooting some of the issues that can arise from time to time. This guide, while not comprehensive, is a starting point for the most common questions that come up when building lighting for your scenes.
I have not added any information about using Swarm Agent and Swarm Coordinator for setting up light builds for multiple machines or a build farm. This is something I would like to get to in the future, it’s just not something I can commit to at the moment.
Hopefully this will help anyone who is experiencing issues when building lighting. If you have anything to suggest or would like to see added please feel free to add a comment here. I cannot guarantee that I will be able to add it, but I’ am more than happy to consider it for the Wiki. 
WIKI Guide: Destructible Troubleshooting and Tips!
Destructible Troubleshooting and Tips Guide
Recently finished basic and common questions guide for Destructible meshes for the Wiki. This guide will have basic questions and answers along with mention of some limitations and tips that may be helpful.
These are some of the most asked questions that those new to Destructible Meshes have come across. If you have any suggestions, or something doesn’t make sense please let me know and I can update it to be more clear.
This thread is superb! I’ll probably be bombarding you with questions later but for now all I can say is a big thank you!
Right, so I come from a CE background and the best way to do destruction in CE was having it predefined:
https://dl.dropboxusercontent.com/u/30654692/destruction_example_02.jpg
- Nodes represent the breakpoint (like nails)
- The black mesh is the foundation mesh (attached to the world)
- The white mesh are the chunks
- The red mesh are debris pieces which are spawned when a chunk is destroyed.
So, my question is how would I recreate the above in UE? I’ve read through your tutorials and looked at sample assets and i’m not sure if the above example is even possible? Is it a case that the engine automatically checks the mesh to see how many objects are in the FBX and each object is turned into a chunk when imported in engine? If that’s the case, is it even possible to allocate debris (red debris in pic above) to each chunk?
Final question for today. Lets say you have a power pole and a large vehicle hits into it. In an ideal world the pole would fall over like a tree. However, you’d also want the pole to be split into chunks to allow a rocket to blast it in half. That way the pole has 2 ways of being destroyed, run into and blown up. How exactly would you do this? In CE, the nodes act as nails and therefore if the vehicle damaged the bottom nail the ones above would remain intact and therefore would fall down intact. Can this be reproduced in UE? Apologies for the question overload but i’m trying to understand the scope of the destruction technology. As lets face it, destruction is awesome!
No problem on the questions. I don’t have the time at the moment to setup anything specific to show, but I’ll try to give a high-level overview of where I would start to look for setting something like this up.
**Question 1: Pre-defined destruction. **
This is possible, it just requires using Blueprints rather than specifically the Destruction Editor. This is actually something I’m really interested in setting up as an example on the Troubleshooting Wiki for Destructibles that I recently posted. This would be really useful for those who are using mobile that want to use destruction as well.
The way I would start approaching this is having my separate pieces and setting up a Blueprint that would do some checks for damage and then spawn the relevant chunks that are needed. It doesn’t seem to overly complex to set something simple up, but if you require something more specific it can probably lead to a lot of tweaking to get the look and feel just right.
This one is high on my list of examples I would like to set up, it’s just a matter of finding the time to do it, which I’m limited on at the moment. If I did set something up it would probably be a really simple example for the time being.
Question 2: Multiple Damage scenarios for DM
I’ve not set this type of example up before specifically, but it may be better to use a Basic Destructible created in UE4 or in PhysXLab with multiple Destruction Depths. I would then look into the blueprints that will be applying the damage to the DM and casting to it specifically.
As an example using Unreal’s Destruction Editor/PhysXLab:
- A single DM with basic settings, fracture, etc.
If I wanted the Vehicle to cause specific kinds of damage I would open the Vechicle BP and setup the logic here. I would use a Cast to Destructible node and then from there you can apply the damage in a way that you see fit. You can spawn specific particle emitters, or whatever you need since the vehicle’s hit will be the only thing applying damage to the DM.
If I had a weapon, like a rocket launcher, I could do the same thing with this where I cast to the DM and it applies damage in a specific way, or I don’t have to cast specifically do the DM unless I want the rocket to ONLY affect the DM.
Does that make sense?
If you want to only use a predefined form of destruction like in Question 1, That would be a similar setup. You would just apply the Cast To [name of your Destruction BP] to apply damage in a very specific way.
Unfortunately, I’m not familiar with CE or even Unity’s ways of handling destruction, and I don’t have any specific examples I’ve setup at the moment to share. If you have an example from CE that you can share a video of I can take a look and when I do find the time I can attempt to set up something similar for comparison. I was not aware that CE handled destruction in that way, so it’d be nice to see some alternative methods and get examples together where possible.
Feel free to ask questions. I don’t guarantee I’ll have an answer, but I can try! As with anyone working in any engine, I do have my own interests and specialties, as I’m sure you’re already aware of from this thread. 
Thanks for the reply! If you wanted to use any of my test examples then i’ll throw up my 3ds files. I experimented a fair bit with destruction models in CE and managed to do some pretty nice samples, the only issue with CE was their frankly inadequate code. So for example the damage spread was very tricky to adjust and there was no such thing as low/high resistance (looking forward to playing with that!). Also no matter how much mass you gave the debris they always felt like they were made from foam and not stone/concrete. All style and no substance!
Predefined destructible houses like this were great fun to setup and loads of fun to blow up! I’m hoping to do something similar in UE. But as I’ve never played around with destruction in UE i’m having to work out how each method will be done. Blueprints sounds like probably the best direction as i’d have more control on the finished visual.
I remember the most fun I had was being able to drive tanks through buildings and leave a tank shaped hole! Anyhow, thanks for the time! Now time to experiment! 
Destructibles are definitely an area I really enjoy, if that’s not already evident.
I’ve been working with our Learning Resources team part-time split between my time with our Engine Support team and I’ve been updating the Destructible stuff that is in our documentation.
Recently, I’ve updated the Destructible Properties Matrix page which hadn’t been updated to include a lot of the settings.
I’ve setup a new map for the Content Examples that will include 5 rooms and break down all the Destructibles properties. There will also be documentation pages to go along with these as well. This likely won’t be released before 4.10/4.11. I’ve still got a little bit more to finalize and finish up the pages. This is more a side project at the moment. So keep an eye for that in the future!
Lastly, I’ve recently added a new page that is in the process of being peer reviewed for the DM Editor UI. If all goes well that should be pushed live in the near future as well. It’s just a basic overview similar to thisStatic Mesh Editor UI page.
Unfortunately, Destructibles aren’t a major priority for Epic in their games at the moment so there are some known issues, but there has been a lot of progress since the engine was released publicly in March '14.
Twitch Streaming
Currently, I’m looking to gauge any interest in some twitch live streams covering any areas in lighting, physics, or destructible meshes?
As with all my content in this thread I must preface this as not being affiliated with any live streams that Epic does. Really, I’m just wanting to gauge the interest in this before posting with my personal account and setting up a time and topic. If I see enough interest in this post, I’d like to also know what you would like to see with regards to the aforementioned topics. Keep in mind that I’m not a master of all things.
If anyone is interested in this, I request the following from you in a post here:
- **Out of the three topics, Lighting, Physics, or Destructible Meshes, which would you like to see. A rank from 1-3 in order of preference. **
- **With each topic or any single topic, list out as many or few things that you would like to potentially see covered. **
- If you have any other suggestions, feel free to leave those as well.
This is something I’ve thought about doing for a while, and if there are enough people (heck, even if it’s just a few) that are interested in learning anything in these areas I’m interested in helping.
Let me know your thoughts!
all guides list awesome thanks mate.
, while experimenting with destructible mesh stuff today I found a possible issue I thought would be worth posting. The Large Chunk Threshold setting doesn’t work if you’re using a Custom Collision Channel. I’m using a custom “Player” channel for my player capsule and was puzzled as to why it would collide with the chunks no matter how high I put my threshold. Eventually, I found that it worked as intended if I set the collision on the capsule to “Pawn”. Would love some finer collision control over the chunks someday.
And if anyone out there is struggling like I was, check your custom collision channels!
I’ll check that tomorrow and bug it if that is the case.
Is your “Player” collision channel setup similarly to the ‘Pawn’ or any other collision channels? Or if you want to post the settings you’re using for it I can see what I get on my end.
Thanks!
I gave this a go, and I’m seeing no issue with what I’ve tried to setup. I’ve setup a simple collision profile and object type with the default settings. I’ve set the object type to Block and the Preset is using Collision Enabled.
If you’ve got a different setup that is causing this, it may be the way it is currently setup, or there could potentially be an issue here, but I’m not seeing the same results on my end. Feel free to post back here with your setup and I’ll have a look when I can.
Thanks!
**Twitch Stream: Destructibles Overview and Q&A **
Stream Subject: Destructible Meshes
When: Saturday, October 3rd
Time: 2:00 PM to 3:00 PM (EST) [or longer if needed]
Outline:
- Destructible Mesh Editor Overview
- Limitations and General Overview of PhysX Destruction
- Light overview of PhysX Labs. Not intended to be an in-depth overview.
- Types of Destruction (PhysX DM, BP/Mobile Prefractured Mesh, and Animation)
- DM Example: Basic setup with Impact Damage
- DM Example: Multiple settings for more complex setup
- DM Example: Wall with Non-Fracturable chunks
- Details Panel settings specific to DMs
Finish with Q&A
Destructibles Overview and Q&A now available to stream on YouTube.
**Twitch Stream: Occlusion Culling and General Lighting Review and Q&A **
Stream Subject: Occlusion Culling and Lighting
When: Saturday, October 10th
Time: 2:00 PM to 3:30 PM-ish (EST)
Outline:
YouTube Video: PBF: Brief Overview of Occlusion Culling - YouTube
Part 1:
- General overview of what is Occlusion Culling.
- Simple Examples of how the system works in UE4
- Methods to basic level design with Occlusion culling
- Methods to reduce pop-in of meshes
- Respond to Questions
Part 2:
This section will be more open forum. We’ll go through the following Levels in Content Examples:
- Lighting
- Dynamic Scene Shadows
This part of the stream will focus more on general questions asked and see where we go. I’ll setup some examples that come up often if time allows.
- Review Content Example Maps
- Answer Questions in each Section.
- Explore some simple examples not necessarily demonstrated in CE demos
- Quick look at Swarm Agent/Lightmass
- Explore a few of the settings for Lightmass in World Settings panel
- Answer questions along the way.
Thanks so much ! Just found this awesome thread. What about lighting? Especially the Light Function system. I’m looking for how to ‘faking’ multiple lights from single light using light function but couldn’t find any tutorial or example for that. Thank you again!
Lighting is definitely something I would like to dedicate more time to do for any tutorials or discussions, but I’ve not had the time as of late to really get anything out there.
As far as Light Functions go, this is just a gray-scale material that is applied to your light. Not exactly sure what the usage would be to make it appear as multiple lights. If you could clarify with an example or some more in-depth explanation I can possibly help.
I think this is relevant to this thread
http://www.scriptspot.com/3ds-max/scripts/rigid-animation-to-skinned-mesh
A very good example of that would be car headlights. So instead of placing two spotlights, maybe it’s possible to just use one spotlight with the light function, and it appears as if we are using two spotlights.