The new Crowd Sim in iClone 8.4 has been enthusiastically received by the iClone community since its release. It is now easier than ever to add crowd filler to indoor and outdoor scenes to give more movement, more action, and more life to a scene. While I haven’t yet released my full review of the crowd sim (still experimenting with certain aspects of it) I have been more than pleasantly surprised with its ability generate mesh-based crowds in little time.
From a handful of pedestrians and seated characters to armies running into the hundreds, I have had few problems and practically no learning curve (my favorite thing about Reallusion products) as I have tested many different scenarios involving different-sized crowds. A lot of those scenes have used anywhere from a dozen or fewer actors to over 700 mixed LOD 1 (7K) and LOD 2 (800 KB) characters decimated and optimized in Character Creator 4. iClone handled these crowds just fine but when switching to Edit mode on a few hundred characters be prepared to wait a minute or so.
Yes, I know. A minute or so can seem like forever but I am talking about changing hundreds of Lite meshes to edit to make changes or duplicate. These edits can be slow due to the sheer computational load placed on the computer. Once switched back to Lite mode iClone is back to normal.
One thing to keep in mind is that while the new Crowd Sim can create filler crowds it is not designed to create massive crowds like armies or stadium crowds in the thousands or tens of thousands. As usual with new 3D tools, you give us an inch and we’ll want a mile because we always want more. So let’s take a look at the difference between these massive high-end crowd generators versus the Crowd Sim.
HIGH-END CROWD GENERATORS
When you look at crowd solutions like Massive for Maya priced at $3500, $500 for monthly rental, uCrowd at €1,600 per month, Golaem (an incredible crowd tool) comes in at €7,000 per year while Goaem Lite can be rented for €1000 per year you can see the major problem. None of these are what we might call “budget-friendly” unless you are using them commercially to support the cost.
Simulating huge crowds is hard to justify for the average amateur or home animator and is out of the reach of a lot of freelancers who would love to work at this level of crowd creation. I can spend way too much time playing around… err… experimenting with these types of crowd generators instead of getting the work done but the budget for these tools just isn’t there unless it is baked into a contract or provided by your employer.
Most of these heavyweight and high-price tools rely on a variety of ways to bring down the poly count like basing the crowd on a particle system with lower computational overhead. Crowd agents, proxies, and other means are used to produce mixed crowds that are not generally one hundred percent mesh based as are crowd sims like iClone.
One of the reasons 3D crowds in triple AAA productions seem to flow is because they do. In some cases, the particle simulation is almost like flowing water with the crowd being deflected by large objects while moving others smaller objects with their flow. Anyone that worked with fluid simulations can recognize that flowing movement and yes it looks great in the right situation… with the right budget or a rich grandmother who throws money at you.
How did Reallusion work on the crowd problem to give us what we have? Knowing this company and its leadership, I would bet this was long ago baked into a roadmap of future research and development because we needed some other tools like Optimize and Decimate along with the powerful Motion Director tool to get the system we have today. I would be very surprised if the Crowd Sim “just happened” because few things at Reallusion just happen without planning but it could also be the natural evolution of the prior tools and Reallusion adapted the roadmap for it. Either way, we’ve wanted a crowd sim and now we’ve got a crowd sim.
LITE MODE
Lite Mode, to me, answered my question of how they pulled this off. Many of us have tried other solutions like the crowd generator in 3DS Max (too limited) and Anima Crowd (a bit clunky and can be a hassle to get characters and assets into). We always ran into a wall as to how many characters iClone could handle as it was easy to create the crowd, but it could bring iClone to a crawl if it had too many characters.
It didn’t seem to matter so much about the poly count as it did the number of characters we were trying to use. Past a certain point… usually somewhere between 50 to 100 characters, iClone would start protesting and staging a work slowdown until you gave it something less resource-intensive or just grind on through the process. Lite mode solves this problem as explained below.
EDIT MODE VS. LITE MODE
Whenever you can’t edit a group of characters created with the Crowd Sim that is due to the new modes and this is where these modes come into play. The Lite mode flattens everything but the transform animation to reduce the computational overhead to provide a smoother real-time playback and working experience.
- When in Lite mode, the only feature left for the characters is the Transform settings.
- All the character’s animation-related settings or effects will be temporarily flattened and inaccessible in the Lite mode.
- You can only see the Transform track in the timeline.
- If the character animations utilize constraints, such as Reach or Link, then perform Flatten All Motions with Constraint before converting the character to Lite mode.
Now don’t panic. When it says it flattened the animation-related settings, making them inaccessible, it doesn’t mean you’ve lost all that animation information. Just select the character or characters and press the Edit Mode button to get all that back in editable form.
This is a lot easier than you may think. While working with a 735-character Roman Legion army I created groups of 49 (7 X 7 rows and columns) evenly spaced which is very easily done in the Crowd Sim. I needed to make some changes including duplicating the groups instead of generating them every time. I could easily select a group or groups and press the Edit mode button giving me back control to make extensive edits.
Just don’t forget to change them back to Lite mode when finished.
TIP – Don’t panic. If you can’t control or edit a crowd-generated character or characters you need to select that character or characters and change them to Edit mode. Lite mode only allows for the transform to be available. Everything else is flattened unless you go into Edit mode.
WALKERS & STORMTROOPERS
One of my early attempts was a Star Wars-themed crowd with Stormtroopers and bipedal Walkers. Out of necessity, I altered the knees to go forward instead of backward as they were originally. This was so the walkers could access iClone motions including the same motion as the Stormtroopers.
I rigged the AT-ST/A Walker with AccuRIG in Character Creator 4 and masked out the bones from the pelvis upward. You could leave those bones active and possibly rotate the weapons on each side, but time was short, so I used masking to eliminate unforeseen problems with “ghost bones” that are not being used.
I created a custom Actor Group with a Walker and several Stormtroopers so I could drag and drop the Actor Group, with randomization options, onto the battlefield in a skirmish line with forward elements. I used three groups that totaled three Walkers and around 100 Stormtroopers which gave iClone absolutely no problems. It ran the scene as it would any without a sign of trouble. A very pleasant surprise.
As you can see from the image above right, I have only used the legs (white bones) and masked out all the bones from there up to the head (black bones) to quash unneeded movement from human walking motions which opens the iClone motions library for use with the Walker.
WARNING: VIDEO BELOW CONTAINS AUDIO
ROMAN LEGION
After this, I went back in time a bit to create a Roman Legion from Xurge 3D’s excellent Julius Ceasar outfit in the Marketplace. I created 5 variations of Roman soldiers at 7K and 800 KB. This allowed the army to have one 49-man 7K unit close to the camera and the other 800 KB units around and behind that main unit as the camera pulled back.
I added a higher quality character closer to the camera riding horseback, inspecting the Legionnaires. The horse is an older iClone prop, Warhorse, with built-in animations. The 736-character scene (including the main character) gave iClone no problems until I added the old, inefficient, physic-enabled banners. That slowed real-time playback and added hours to the render. With the banners set to smooth it rendered in about half an hour. In fairness, those banners were ancient, from the old Bullet physics engine, and were way too heavy in polycount.
WARNING: VIDEO BELOW CONTAINS AUDIO
A 735-character army may not seem huge but 735 people in a street scene would be extremely busy so keep all this in context. A lot of scenes are not going to require thousands or even hundreds of characters as you don’t want to make a scene so busy it’s hard to keep up with the characters and the story they weave.
I haven’t finished stress testing the Crowd Sim yet, but I also haven’t come into a scenario where iClone couldn’t handle a crowd once it was all in Lite mode. Edit mode can be slow if you open 400 hundred characters at once in Edit but iClone never crashed. I could move them, duplicate them, and work with them, it just took some time, but I was trying this in the extreme for testing.
The new Crowd Sim is just what we needed without having to shell out big bucks for an extensive crowd system that probably wouldn’t be blessed with iClone’s well-known simplicity. For those that want Lord of the Rings-size armies, you can always create them in iClone and use the multi-take recording in Unreal Engine.
MD McCallum – WarLord
Digital Artist MD “Mike” McCallum, aka WarLord, is a longtime iClone user. Having authored free tutorials for iClone in its early years and selected to write the iClone Beginners Guide from Packt Publishing in 2011, he was fortunate enough to meet and exchange tricks and tips with users from all over the world and loves to share this information with other users. He has authored hundreds of articles on iClone and digital art in general while reviewing some of the most popular software and hardware in the world. He has been published in many of the leading 3D online and print magazines while staying true to his biggest passion, 3D animation. For more information click here.
