If you are using one of the OpenGL graphical features (Shaded Model, NSC Shaded Model or NSC Object Viewer) and the rendering does not look correct (i.e. aliasing or artifacts in the image, for example), you should check to ensure that you have the latest version of the driver for your video card. You can start by checking with the manufacturer of your video card. The vast majority of video card manufacturers have drivers available for download on their websites.

(Please note:  ZEMAX Development Corporation cannot provide technical assistance with finding and downloading video card drivers. If you need this type of assistance, you should contact your IT administrator or computer manufacturer.)

If you have installed the latest video card driver that your video card’s manufacturer has to offer and you are still experiencing problems with the OpenGL features in ZEMAX, you can also try installing the Microsoft version of the driver for your video card using the following procedure:

-From the Start menu, right-click on Windows Update.
-Click on "Run as" and select the 'The following user:" radio button.
-Enter the "User name" and "Password" for a user with administrative access to your computer.
-On the left side of the webpage that opens up, click on "Use administrator options".
-On the Administrator Options page, in the "Update multiple operating systems" section, click on "Windows Update Catalog".
-Check the "Find hardware driver updates" check box.
-Check the "Video" box.
-Select your video card hardware manufacturer and operating system.
-Look through the drivers that are listed and find the newest one for your exact model video card.
-Download the driver and unzip it.
-Right-click on the desktop and select "Properties".
-Click on the "Settings" tab and then "Advanced".
-Click on the "Adapter" tab and then "Properties".
-Click on the "Driver" tab and then "Update Driver".
-When asked if you want to connect to Windows Update, select "No" and then click "Next".
-On the next screen, click on the radio button "Install from a list or specific location..." and then click "Next".
-Click on the "Search for the best driver in these locations" radio button.
-Check the "Include this location in the search" check box.
-Browse to where you unzipped the driver files.
-Click "Next" to install the driver.

Once the driver has been installed, restart your machine.

(Thanks to Mike Tocci for providing the procedure described above.)