A quick guide by Kate @ www.parsimonious.org

What is a Poly Count? (or Polygon Count)

Non-Maxis or New-Mesh bases (objects with a different shape from the stuff that comes with your game) are often referred to on Sims websites as having a 'poly count' - this is usually given as a pair of numbers (faces & vertices)

The simplest answer is the higher the numbers go, the more complicated the object is, therefore more your computer has to work when you add that object to your game which can lead to problems. 

The more technical answer is that these numbers refer to properties of the object mesh. The 'mesh' is the 3D wire-frame that gives the object its shape, the vertices are the points where the 'wires' meet, the faces refer to the spaces in between, these points and faces together make up shapes or polygons, your computer needs to calculate the coordinates of each of these polygons when your game is running so it knows what to display where.

For Parsimonious New mesh objects we give 3 values for the Poly Count. 

• V = number of vertices 

• F = number of faces 

• T = number of tiles

You can see by hovering over the traffic light poly count button in the single item information: in this example this item is what we consider to be a medium polygon object with 1568 Faces (F) 1780 Vertices (V) and it occupies 2 Tiles (T) in game.

The numbers for individual objects don't really matter by themselves, however the totals of objects in a particular space (the lot you are currently playing) does, here is a simplified example showing how the use of objects in a limited space affects your game. 

Here we have a 6 tile space in which we have placed a double bed which has 4000 vertices and 4000 faces, it is the only object occupying the space therefore the total polygon count for the space looks like this - each grid square represents one game tile :-

1 Object. Total = 4000 vertices, 4000 faces

Here is the same space which has a different selection of objects with 4000 vertices and 4000 faces each (the same as the bed) - the end result is that the same space can give your computer much more work to do simply because the smaller objects add up to a much larger number of polygons:-

6 Objects. Total = 24000 vertices, 24000 faces

The total is much higher in the second example for the same space so your computer has to work harder. Obviously you have a lot more tiles than just 6 on a lot which means if you have lots of high polygon objects on a lot then your computer can get really busy trying to display all your items.

So what is a 'good' poly count?

Well according to Maxis around 800 vertices and 800 faces or less per in-game tile is the ideal, this is pretty hard to achieve with most objects, they couldn't do it themselves, many Maxis items have much larger counts than this. A lot of sites put out objects which have thousands of polygons, counts over 10000 and even 20000 are surprisingly common - of course with such high levels of detail the objects look gorgeous in the previews but unless you've got a really good computer these will likely bring your game to a crawl. 

I would suggest the closer your computer is to the minimum system requirements for The Sims 2, the more you need to be concerned with these poly counts - if you have problems with very sluggish game play and your game settings have already been optimized as much as possible then try and ensure you do not add items of more than 3000 vertices/faces per tile to your game or try and use high polygon objects sparingly.

How can you tell if an object is high poly before you download it?

If in doubt ask the website you're downloading from to give you the above information about their objects, or alternatively 

If the site doesn't provide this information or when you ask they give you a response along the lines of 'er... what?' then you might want to avoid using their objects. Many sites who use meshes they didn't make put out objects which are really too complex for The Sims 2 which is a low poly game and if the creator doesn't understand the issues involved in poly counts then they may be making other more important mistakes which could put your game or even your computer at risk.

If you're determined to have a particular object anyway you can install SimPE and find out the polygon count for yourself, open the object with SimPE, on the left pane look for the 'Geometric Data Container' (GMDC) - click on it, in the bottom pane click on the 'Plug-in View' tab and you'll find the vertices and faces values displayed in the bottom left corner. Remember to take into account the number of game tiles the object occupies when considering the numbers displayed.

Will my computer crash if an object is too complicated?

What is likely to happen is your game will become increasingly slow or even become unresponsive (frozen or 'locked up') after placing an object with a very high poly count. Generally speaking if you want to use objects that are particularly complex then do so on a smaller lot with less Sims, keep the rest of the furnishings simple, don't put too much furniture on the lot but be prepared to ditch the object if game-play is too sluggish. As you can hopefully see from the grid examples above, how you use the space on the lot does make a real difference to what your computer needs to do and therefore how it will perform. 

That said, your game shouldn't be irrevocably damaged by using an object with too high a polygon count - simply remove the object from your game files, any instances on existing lots will be replaced by a Maxis item of a similar type.

I have a Sims 2 website, can I link directly to this page?

Yes certainly - the direct URL for this page is http://www.parsimonious.org/faq/helpo2polycount.shtml