On the Madness of Crowds

I thought I’d post about a common problem in 3D art, and what I have done to solve it.  It is called the “crowd problem” and has been a difficulty with all 3D animation.  The first 3D animated movie Toy Story solved it by never having any crowd scenes.  AntZ, the second 3D animated movie had hundreds of ants doing the exact same thing which is easier than in A Bugs Life which had dozens of identical ants doing completely different things.

The above picture has 35 3D people in it. It serves as the background picture for about 4 or 5 pictures where things are happening in the foreground.  Here is what I did to solve the “crowd problem”:

In the Date Ariane game, this was the biggest crowd scene in the game, consisting of 8 high resolution characters.  The giant gap in the middle was filled in with Ariane, and that creepy guy who tries to fondle Ariane on the dance floor.  The absolute maximum of high res characters I can produce at one time is five, and I have already posted a few pics from Something in the Air with five people in it.  The above pic was produced by rendering the four people on the left and the four people on the right seperately, then combining the picture.  This is a very time consuming process however.

Date Ariane supposedly takes place on a weekday when places are not so busy, SITA takes place on a Saturday, and every place is crowded. I need ways to shortcut.

The solution is a tool that generates generic crowds for you called M.O.M Crowd Generator.  It throws in flat panel images of people walking or standing which can fill in a background crowd fairly easily.  The primary issue I have using it is that all the people have a white outline around them like older movies when they did green screen effects.  A little blurring makes the outline less noticeable, and since they are background characters, I can hide them with high res foreground characters.  Notice that the front characters I’m using are the exact same I used in Date Ariane (even the exact same poses).  Much of this crowd will be hidden by 4 to 5 characters in the immediate foreground.

One of the places you can take a date in SITA is the amusement park.  The same amusement park in Date Ariane.  If you compare this picture with the Date Ariane one, you will find the main difference (besides the obvious different character in the foreground) is the M.O.M generated crowd in the background to make the place look a lot busier. The props and the high res characters are identical in both.

Another crowd scene is the above mentioned house party scene.  This requires a better crowd than the M.O.M tool can produce.  Especially since I wanted most of the crowd to be holding the traditional red Dixie cups you see at all of these house parties.

I also wanted a dance crowd where everyone is actually dancing.  The solution is to use low rez male and female characters.  While I can only manage 5 high res characters in a scene at a time, I can easily manage 30 low res characters in a scene at a time.  They can do pretty much everything that high res characters can do except look good close up, so I throw some high res people into the foreground to make the crowd look better.  There are some major flaws with these low res characters, especially the females.  Someone decided to add ambient lighting to the skin to make them look better in daytime, but my crowd scenes are set at night, and it took a bit of effort to get rid of that ambient lighting (hint: pp2 files which tell how to texture and light characters are just text files that you can manipulate in Notepad using find and replace.)

I still have two more big crowd scenes to create, one on a beach during daytime, and one in a ComicCon type setting with a lot of costumed characters.  So back to work.


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.