As I wrote in my last post, I feel that I need to research around poly counts further, in order to understand what a 'high poly count' is in games and what is considered 'low'.
Upon researching, I found a handy post on various games' poly counts of certain assets:
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| http://www.rsart.co.uk/2007/08/27/yes-but-how-many-polygons/ |
I feel this post is incredibly handy in regards to when I start modeling, as I will be able to compare my poly counts to that of games already on the market.
Gaming models have to be more efficient in their use of modeled details to maintain a manageable data set to render. The reasoning here is that an efficient streamlined environment composed of the lower poly assets will render more smoothly and give better frame to frame renders during gameplay. What your gaming system is in essence, is a renderer that constantly has the task of rendering each frame of gameplay at 30 frames per second. Some games hit the magic number of 60 frames a second. If this rate drops during the game the result is a poor experience and hampered gameplay. This applies to PC games as well, although they will typically have more processing power to run higher resolution models.
With constant innovations and improvement in next-gen consoles and technology, development of more advanced techniques and processes give us more detailed looking models at a lower cost. One of these advances is the use of normal mapping. A normal map acts like a bump map, in that is adds surface detail without adding polygons. Normal maps go a step further because they actually replace the surface normal with new multi-channel data to represent an X, Y, Z coordinate system. What this means is that we can create a high resolution model of 2 or 3 million polygons and bake the high resolution detail down to a normal map that retains the component space data of that high resolution model. It is then a process to create a streamlined model that emulates the general proportions of the high density model, but at a much more efficient poly count of 2500, for example. Once the normal map data is applied to this low-res rendition of our high-res monster, the model immediately looks more complex geometrically but at an affordable rendering cost. Movie productions also use Normal Mapping techniques, but the asset that they use the Normal Map on is typically a more detailed model than the one used in games.
http://www.siggraph.org/publications/newsletter/volume-41-number-2/modeling-techniques-movies-vs-games
Next I found answers to most of my thoughts on this website: http://simswiki.info/wiki.php?title=Game_Help:Poly_Counts
Why do poly counts matter?
Poly count can be very important. Inside every computer is a graphics card - it's the part that makes all the pretty pictures. The graphics card has to plot the position of each and every poly in 3D space. It also has to render the surface of the poly itself... and all the textures, and any special properties like reflectivity/shine, and any transparency like cut-out strands of hair.
Every poly you add is just a bit more strain, more work for your graphics card to do - and it has to do it every frame, continuing to render all those polys as the game goes on. This can generate a lot of heat, and a lot of stress on your graphics card, especially if it's not incredibly good.
The effect of polys is cumulative - one high poly item generally will not cause problems. But if every item you have is high poly, or you use a specific extremely high poly item over and over, you can begin to experience problems like:
- Lower frame rates - The game gets choppy and slow.
- Slow scrolling - It's slow and difficult to move across the lot.
- Slow zooming - It's slow and difficult to zoom in and out.
- Game freezes - The game stops responding and has to be forcibly closed without the option to save.
- System freezes - Your entire computer locks up and stops responding. You have to shut it down using the power/reset button.
- Graphics-related errors - You may overload your graphics card, crashing the game, dropping you to a lower resolution, and forcing you to reboot/shut down.
- Graphics anomalies - An overstressed graphics card may begin displaying gaps in hair at the forehead or back of the neck, sparkles and strangeness in other meshes, blurred textures on sims and objects, blurred/crunchy/shredded thumbnails, blurred mirrors, or other display-related weirdness.
Needless to say, any of the above is bad, and if you begin seeing increasing signs of stress, it can be a sign your graphics card is being overstressed. Overstressing a graphics card may eventually cause it to fail - you'd have to purchase and install a new one (or get someone to install it for you), which can be pricey.
This is also not to say that all of the above is always caused purely by high poly content and related problems... You may just have a crappy graphics card... Or it may be overheating because of dust/dirt/age/lack of proper cooling... Or you may need to update your graphics card's drivers to fix certain issues... Or your graphics card may just be having its own strange issues...
But all of the above -can- be caused, at least in part, by the stress put on a graphics card by having to render too many polys.
