One of our main development objectives for Combat Flight Simulator 2: WWII Pacific Theater was to improve the overall image quality and performance of the game. However, we also wanted to offer you flexibility to pursue image quality and performance tradeoffs that can fine-tune CFS2 to your system. With so many combinations of hardware and software available, it's impossible to replicate every configuration. So, we've added more graphics settings which can be adjusted to achieve the look and feel you want. This article will help you adjust those settings, which will help you create the best CFS2 experience.

To make general adjustments to CFS2, you will use the Settings dialog box. To make fine-tuning adjustments, you will use the Advanced Settings dialog box.

Using the Settings Dialog Box

To open the Settings dialog box, go to the Options menu and click Settings .

Figure 1: Settings Dialog VIEW LARGER IMAGE

The Display section on the Settings dialog box includes a slider that sets the overall image quality .

Moving the slider to the left reduces the complexity and graphic detail displayed, but increases the system performance. Conversely, moving the slider to the right improves the complexity and graphic detail displayed at the expense of system performance.

You can also check the Auto-performance adjustment checkbox. When this box is checked, CFS2 adjusts several graphics settings to deliver the best performance for your system.

The Player defined check box remains dimmed until you make adjustments in the Advanced Settings dialog box. Once you do that, you can restore default settings by deselecting the Player defined check box.

Using the Advanced Display Settings Dialog Box

To adjust individual display settings, click the Advanced settings button in the Settings dialog box.

Figure 2: Advanced Display Settings-Hardware Dialog VIEW LARGER IMAGE

The Advanced Display Settings dialog box contains two tabs at the top. Click the Hardware tab to see options for adjusting a 3-D graphics card. If you installed a 3-D hardware acceleration card, CFS2 recognizes it, automatically selects it under Device, and selects the Enable hardware acceleration check box. If you don't have a hardware acceleration card, this check box is unavailable.

Settings in the Advanced 3-D hardware options area control functions on 3-D accelerator cards. The default settings reflect our best estimate of the settings that specific cards need to deliver the best performance. The following list briefly explains each option.

• No filtering: No filtering is applied to the textures on scenery and objects-they appear as pixels on the screen. This option improves system performance but reduces image quality.

• Bilinear filtering: Most 3-D cards support this option; filtering eliminates the "hard lines" between different textures. However, with this option selected, you may see "flashing" lines between textures or in the distance. Selecting this option slightly decreases performance.

• Trilinear filtering: This advanced filtering option tends to reduce the "flickering" when bilinear filtering is also selected, but reduces performance. We recommend always having this option checked.

• MIP mapping: This basic filtering method maps "layers" of texture sheets depending on some rather complex algorithms. We recommend always having this option checked, unless you see strange things with textures, such as textures turning black or in obviously wrong colors, or "flashing."

• Anti-aliasing: This option smoothes the edges of objects. Not all 3-D cards support this option, and selecting this option will reduce frame rate. With this option checked, you may also see "banding" in the sky. (Banding produces different shades of blue in the sky instead of a smooth transition from lighter to darker blue.) If you see banding, try changing your resolution to a 32 -bit mode (such as, 800 x 600 x 32 resolution).

• T&L (Hardware Transform and Lighting): This advanced hardware option controls how your video card handles transformations and lighting effects. Before you select this option, make sure your 3-D card supports this feature. Your system may become unstable if your video card cannot support T&L effects. Selecting this option may improve performance, but if you experience other display problems or if the game "hangs," uncheck this option.

• Resolution: This option controls the main image quality by defining the number of pixels drawn on the screen. Lower resolutions produce better performance, but higher resolutions improve visual details and image quality. Cockpit instruments look better at or above resolutions of 800 x 600, and the terrain always looks better at higher resolutions. Reducing resolution to 640 x 480 x 16 produces the best performance possible.

Solving Display Problems

Unless you experience problems, you should generally use the defaults for your 3-D graphics card. If you do experience problems, try the following steps in this order. Between each step, launch CFS2 to see if the problem is fixed. If it's not, try the next option in the list.

1. Turn Anti-aliasing off.
2. Turn T&L off.
3. Set the Resolution to a lower value (lowest is 640 x 480 x 16).
4. Select Bilinear filtering.
5. Select No filtering.
6. Turn MIP Mapping off.
7. Uncheck the Enable hardware acceleration check box.

Adjusting Display Settings to Improve Image Quality

If you're not having display problems with the default settings, you can change the following settings to improve image quality. Proceed in the order of the list, and launch CFS2 between each step to test the effects. If you don't notice any undesirable performance changes, then move to the next step.

1. Select a higher resolution.
2. Select the Trilinear filtering check box.
3. Select the T&L check box.
4. Select the Anti-aliasing check box.

Adjusting Settings on the Image Tab

The Overall image quality slider adjusts settings for each option on the Image Quality tab in the Display Settings dialog box.

Figure 3: Advanced Display Settings-Image Quality VIEW LARGER IMAGE

CFS2 applies a default setting for the value on the Overall image quality slider. Each value is a conservative estimate of the best tradeoff between image quality and performance. You can make fine-tuning adjustments with the individual settings to meet your performance expectations.

• DEM density level: This setting determines the maximum level of detail provided for terrain elevation data. Lower values result in better performance. Higher values result in more accurate terrain elevation at any given point.

• Max. terrain texture size: This setting determines the size of the textures placed on top of the terrain elevation data. Smaller sizes lower the memory requirements to store the texture, resulting in better performance. Larger textures produce greater detail and look better, but displaying them decreases performance. (To see detail on the ground at its best, move this slider up.)

• Terrain complexity level: This setting determines the error allowed within the terrain elevation data. Lower values allow more error, resulting in more "popping" in the terrain. Higher values result in displaying more terrain elevation data at one time. Increasing this value reduces popping, but also decreases performance dramatically.

• Max. object texture size: This setting determines the size of the textures placed on top of objects. Like the Max. terrain texture size setting, smaller sizes lower the memory requirements to store the texture, resulting in better performance. Larger textures produce greater detail and look better, but displaying them decreases performance. (To see detail on the airplanes at its best, move this slider up.)

• Maximum visibility level: This setting determines the range of visibility. Just as in real life, there is a limit to how far one can see in the distance on any given day. Decreasing visibility reduces the amount of objects and terrain your computer draws. Lower visibility results in better performance. Increasing the visibility allows you to see farther, but decreases performance.

• Aircraft shadows: This setting places shadows of aircraft on the ground or water. Normally these shadows won't reduce performance. Shadows look best in 32-bit color mode. See the Readme document in the CFS directory for more detail about resolution.

• Ground scenery shadows: This setting places shadows for ground objects. These shadows can dramatically reduce performance, especially when they are close to the object.

• Detail texturing: This setting makes ground textures flow together better, which gives more depth to the scenery. Selecting this option reduces performance slightly. Some video cards work better with this option selected. Other video cards may "flash" and create square patterns in the textures. If this occurs, make sure this check box is deselected.

• High detail virtual cockpit: This setting provides a higher level of detail in the Virtual Cockpit view but reduces performance. You may want to deselect this check box if you do not use the Virtual Cockpit views much.

• Effects quality: This setting adjusts the level of detail in all of the special effects, such as fire and smoke. Lower settings remove some of this detail and how long it stays visible. A higher setting shows the greatest level of detail in effects, but also reduces performance.

• LOD target frame rate: This setting works only when the Auto-performance adjustment check box is selected in the Settings dialog box (See Figure 1). The value for this setting is not tied to the default Overall image quality slider, but does default to an appropriate value for your configuration. The position of this slider determines the level of detail (LOD) required to maintain the selected frame rate. CFS2 normally selects the LOD depending on the distance between the object and the viewer. However, when the Auto-performance adjustment check box is selected, you can then adjust the LOD using the LOD target frame rate slider. For example, if you select an LOD target frame rate of 25, the detail of the textures changes as you get closer to that frame rate. So, if you were to experience 15 frames per second, CFS2 would decrease the level of detail until performance improves to 25 frames per second. If you were to experience 35 frames per second, CFS2 would increase the level of detail without allowing frame rate to fall below 25 frames per second.

Adjusting Scenery

There is one final area that concerns graphics and performance. In the Settings dialog box click the Scenery Library button to bring up the Scenery Library Dialog box.

Figure 4: Scenery Library Dialog box and the Scenery Object Density Slider VIEW LARGER IMAGE

The Scenery object density slider at the bottom determines how much scenery to use in the game. All non-targetable objects, such as trees and bunkers, in the global scenery layer are removed when the slider is set to Very Sparse . Lowering this setting improves performance, so adjust the slider if your other performance adjustments still do not meet your expectations.

Note: The Scenery object density slider also determines how dense the objects are in scenery imported into CFS2 from previous versions of Combat Flight Simulator and Microsoft® Flight Simulator.

Reviewing Display Settings

As a guideline, the following list shows a ranking of the settings that affect performance and image quality. Higher ranking items have more affect on increasing or decreasing your performance. Lower ranking items have less affect on your performance.

1. Terrain complexity level
2. Max terrain texture size
3. DEM density level
4. Ground scenery shadows
5. Maximum visibility level
6. Effects quality
7. Max object texture size
8. LOD target frame rate
9. Aircraft shadows
10. Scenery object density
11. High detail virtual cockpit

One important thing to note: your monitor refresh rate setting also influences the frame rate value displayed when you fly. This is a complicated subject, but you really won't see better performance with really high frame rate numbers when they're greater than your monitor refresh rate. For instance, if your monitor refresh rate is set to 75Hz, the most you will ever see in CFS2 is 75 frames per second (FPS), even if your frame rate counter shows a higher number.

If you have a really fast machine and your FPS value exceeds your monitor refresh rate, you can improve your image quality without reducing performance. So, in our example, if you turn on the ground object shadows and your frame rate drops to 75 FPS, then you will see no reductions in performance. On the other hand, you could also increase your monitor refresh rate to take advantage of the extra performance.

If you import aircraft or scenery from previous versions of Flight Simulator or Combat Flight Simulator, one word of caution: Imported aircraft and scenery may not perform as well as the aircraft and scenery included with CFS2. These items will still work with CFS2, but you may have to lower the image quality settings to achieve the desired performance.

Additional Ideas for Improving Performance

• Make sure you exit all other applications running on your computer before starting CFS2. Devoting more computer resources to the game results in better performance.
• The Forward HUD view or Panel view delivers the best performance. The Virtual Cockpit view draws more resources, and the Spot Plane view requires CFS2 to draw your airplane at close range. For even better performance, turn off the HUD display in Forward view.
• Try "zooming in" one level in Forward view by pressing the + (PLUS SIGN) key. By decreasing the amount of scenery that must draw on the screen, you will improve performance.
• If you don't have speakers hooked up to your system, turn off the sound and radio transmissions. This will help devote more resources to CFS2 performance. (You can also turn off damage text if you want.)
• Try turning the Tactical Display off. This may help only in non-combat situations.

If you consider a hardware upgrade, the biggest bang for your buck will be a 3-D video acceleration card and RAM. Good 3-D video cards can make a big difference in image quality. If you find that your hard drive works hard (you'll see the disk light blinking rapidly) while the game runs, a memory increase (RAM) may be the best solution for you.

That should help you with performance tuning. Get your system dialed-in and you'll be tearing holes in the sky in no time.

Good luck up there!