question about graphic setting

[superlarrio]

im not very computer knowledgeable and have a question about my graphics setting...what is the difference between the screen effect-bloom/hdr and which is better? also is hdr worth having on instead of antialiasing?

 

i dont know if/what computer info is needed but here are some specs...

-nvidia geforce 8600gt w/256

-intel core 2 cpu [email protected]

-2gb ram

-windows xp

 

im currently playing at 1024x768 res, antialiasing x4, high video quality preset, all distant rendering checked. all fade distances maxed

 

it runs nice except it can be a little choppy with tree, moutains, stuff like that far in the distance. would turning on bloom/hdr make it run better?...i really dont know what they are

[dezdimona]

Bloom (sometimes referred to as light bloom or glow) is a computer graphics effect used in computer games, demos and high dynamic range rendering (HDR) to reproduce an imaging artifact of real-world cameras. The effect produces fringes (or feathers) of light around very bright objects in an image.

 

The physical basis of bloom is that, in the real world, lenses can never focus perfectly. Even a perfect lens will convolve the incoming image with an Airy disc (the diffraction pattern produced by passing a point light source through a circular aperture) [1]. Under normal circumstances, these imperfections aren't noticeable; but, an intensely bright light source will cause the imperfections to become visible. As a result, the image of the bright light appears to bleed beyond its natural borders.

 

The Airy disc function falls off very quickly but has very wide tails (actually, infinitely wide tails). As long as the brightness of adjacent parts of the image are roughly in the same range, the effect of the blurring caused by the Airy disc is not particularly noticeable; but in parts of the image where very bright parts are adjacent to relatively darker parts, the tails of the Airy disc become visible, and can extend far beyond the extent of the bright part of the image.

 

In HDR images, the effect can be re-produced by convolving the image with a windowed kernel of an Airy disc (for very good lenses), or by applying Gaussian blur (to simulate the effect of a less perfect lens), before converting the image to fixed-range pixels. The effect can't be fully reproduced in non-HDR imaging systems, because the amount of bleed depends on how bright the bright part of the image is.

 

As an example, if a picture is taken indoors, the brightness of outdoor objects seen through a window may be 70 or 80 times brighter than objects inside the room. If exposure levels are set for objects inside the room, windows will be bright enough, when convolved with the Airy disc of the camera being used to produce the image, to cause the image of the windows to bleed past the frames of the window.

 

Use of bloom in computer graphics appeared in demos decades before it entered commercial games. Because of the high theoretical and hardware requirements of the Fourier transform needed to do HDR imaging, many demos use other techniques to implement bloom. However this is becoming less common with modern hardware. It has a reputation for being a visual boost on high-end demos, and has the advantage of taking focus away from uninteresting areas. It has therefore become an often used way of covering up low detailed areas, often due to the demogroups hardware, comporules or skill limitions for this particular demo.

 

The effect is popular in current generation games, and is used heavily in Xbox 360 and PlayStation 3 games as well as the popular GameCube and Wii release, The Legend of Zelda: Twilight Princess. Current generation gaming systems are able to render 3D graphics using floating point frame buffers, in order to produce HDR images. To produce the bloom effect, the HDR images in the frame buffer are convolved with a convolution kernel in a post-processing step, before converting to RGB space.

 

The Afterimage effect is sometimes used to enhance the bloom effect

 

In image processing, computer graphics, and photography, high dynamic range imaging (HDRI or just HDR) is a set of techniques that allows a greater dynamic range of luminances between light and dark areas of a scene than normal digital imaging techniques. The intention of HDRI is to accurately represent the wide range of intensity levels found in real scenes ranging from direct sunlight to shadows.

 

High dynamic range imaging was originally developed in the 1930s and 1940s by Charles Wyckoff. Wyckoff's detailed pictures of nuclear explosions appeared on the cover of Life magazine in the mid 1940s. The process of tone mapping together with bracketed exposures of normal digital images, giving the end result a high, often exaggerated dynamic range, was first reported in 1993[1], and resulted in a mathematical theory of differently exposed pictures of the same subject matter that was published in 1995[2]. In 1997 this technique of combining several differently exposed images to produce a single HDR image was presented to the computer graphics community by Paul Debevec.

 

This method was developed to produce a high dynamic range image from a set of photographs taken with a range of exposures. With the rising popularity of digital cameras and easy-to-use desktop software, the term HDR is now popularly used[3] to refer to this process. This composite technique is different from (and may be of lesser or greater quality than) the production of an image from a single exposure of a sensor that has a native high dynamic range. Tone mapping is also used to display HDR images on devices with a low native dynamic range, such as a computer screen.

[superlarrio]

thank you very much. now another question, which would give me better look and performance hdr or antialiasing since only one can be used at a time?

[billypnats]

actually thats not true anymore, with the new drivers, you can force Antialiasing and HDR at the same time. i don't know how you manage to have nice performance given the system you have but oh well.

 

From my experiences, HDR or bloom wouldn't really effect performance much