We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

What Are the Best Tips for OpenGL® Depth?

By Eugene P.
Updated May 16, 2024
Our promise to you
EasyTechJunkie is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

Editorial Standards

At EasyTechJunkie, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject-matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

The OpenGL® depth buffer is one of the more misunderstood, complex and ultimately useful tools available to a three-dimensional (3D) graphics programmer. There are several ways the buffer can be optimized so the frame rate for a program can be increased, including properly setting the near and far clipping planes. Other tips include clearing the buffer between renders and avoiding scene compositions that can cause the depth to be an issue by placing objects too close together. Some two-dimensional (2D) graphics tricks can be performed easily and efficiently by using the OpenGL® depth buffer. The graphics card that is being used also can sometimes be an issue with depth, so using the correct setting can help to increase speed and reduce needless processing cycles.

One of the first issues that can affect the performance of the OpenGL® depth buffer, also called the Z buffer after the letter that traditionally marks the Cartesian depth plane, is the placement of the near and far clipping planes. These planes define the bounds of what should and should not be rendered in a scene, and their values indicate the distance from the viewer where the clipping should start and end, respectively. An intuitive thought would be to begin rendering at the point where the viewer is, setting the near plane to zero, but this is actually not correct. In fact, OpenGL® does not allow the near plane to be set to zero. If the value of the near plane is very small, a fraction of one for example, then the renderer might not show anything at all or it might fail to sort the depth buffer correctly.

This occurs because the closer an object is to the viewer, the more accurately OpenGL® calculates the position of the object. As the distance to the viewer gets closer to zero, the accuracy calculated increases exponentially. This slows down the rendering time and can lead to odd graphical artifacts and other problems, aside from the fact that the level of accuracy calculated is rarely ever needed.

When rendering 2D graphics, the OpenGL® depth buffer can help to make some operations easier. Using the depth buffer to slightly offset quads that are being used as tiles in a composition can help elements of a tiled scene to move smoothly around without spawning strange effects in the image caused by two polygons overlapping each other in the same plane. Similarly, prepared elements can be hidden out of the field of view or behind the far clipping plane so they can be quickly brought into the scene, possibly even utilizing transformations and rotations to give a special fade in or out effect.

Finally, while the OpenGL® depth buffer can support different hardware sizes for the buffer, it is best to use the 16-bit version. This is because, in most scenes, using a 32-bit buffer can slow the rendering time down. Also, not all graphics cards support 32-bit depth buffers, so dropping down to the lowest common denominator means more people will be able to run the 3D program as it was written.

EasyTechJunkie is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Link to Sources
Discussion Comments
EasyTechJunkie, in your inbox

Our latest articles, guides, and more, delivered daily.

EasyTechJunkie, in your inbox

Our latest articles, guides, and more, delivered daily.