When to swap frame buffer objects in OpenGL?
This article discusses how to improve OpenGL* performance by swapping Frame Buffer Objects (FBO) instead of using a single FBO and swapping surfaces. Swapping is useful when making multiple changes to a rendered image, such as switching color, depth, or stencil attachments.
What’s the best way to switch FBOs in OpenGL?
The recommendation is to use dedicated FBOs for each set in use, rather than sharing an FBO among all attachments. Switching an entire FBO is more efficient than switching individual surfaces one at a time. The article is accompanied by a C++ example application that shows the results of not using and using the suggested technique.
How to see the current performance of OpenGL?
The current performance for each approach is displayed in a console window in milliseconds-per-frame and number of frames per second. Pressing the spacebar toggles between the two methods so you can compare the two approaches. When switching, the application animates the image as a visual indicator of the change.
What are the benefits of bindless resources in OpenGL?
Bindless resources increase the number of dynamic resources a shader may use, from about 256 to 2,000,000 when supported by the graphics API. This change reduces the overhead associated with updating binding tables and provides more flexibility to programmers. Execution units (EUs) have improved native 16-bit floating-point support as well.
How are FBOs used in OpenGL for blurring?
Add in effects like blurring and the number of passes continues to increase. The data for each of these passes are supplied using FBOs. You can use a single FBO and just alter the data attachments as needed, but it is more efficient to create a separate FBO for each dataset and switch between FBOs.
What happens when you draw something in OpenGL?
When you draw something in OpenGL the output is stored in the default framebuffer and then you actually see the color values of this buffer on screen. You can also make your own framebuffer which can be used for a lot of cool post-processing effects such as gray-scale, blur, depth of field, distortions, reflections
Can a renderbuffer object be read from OpenGL?
However, a renderbuffer object can not be directly read from. This gives it the added advantage that OpenGL can do a few memory optimizations that can give it a performance edge over textures for off-screen rendering to a framebuffer.