title: OpenGL
author: Decker, DanielPharos

<img align=right>opengl.png</img>
Settings in this folder are only usable if you have a true OpenGL
graphics-card.

<i>Fade</i>. With this you can enable and disable the fading fog.

<i>Transparency</i>. With this you can enable and disable transparency.
You might need to enable lighting in order for transparency to be applied.

<i>Lighting</i>. With this you can enable and disable the lighting.


<u>Additional options</u>

<i>Texture filtering</i>. This improved the texture quality, mainly under
high angles. It will make the textures appear less blocky and pixelated.
The higher the settings, the better the quality, but also the lower the
performance.

<i>Double buffering</i>. When enabled, OpenGL will render the image
offscreen, and then copy it. This will prevent any weird triangular
flickering from the rendering being visible.

<i>Color dithering</i>. When enabled, OpenGL will dither colors.

<i>'Supports GDI' flag</i>. This will enabled the 'Supports GDI' flag.

<i>Over-the-scene lines+icons</i>. This will draw all the lines and
icons over the scene.

<i>Color bits</i>. The amount of bits per pixel. The higher the number,
the better colors will look. Not all numbers are supported. 16, 24 and
32 are common numbers these days.

<i>Depth buffer bits</i>. The amount of bits per pixel in the depth
buffer. The higher the number, the less chance of objects being rendered
overlapping while they're not. Not all numbers are supported. 16 is the
most common number these days.

<i>Size correction</i>. Corrects misalignments between the image and the
wireframe lines over it. For example, Windows NT's software OpenGL is
known to require a correction of about 0.92 instead of 1; otherwise, the
textured images are smaller than the wireframes.

<i>Display lists</i>. When enabled, OpenGL will use display lists.
Display lists speed up rendering. However, slight slowdowns might be
noticed when changes to the map/model are made, because the lists then
need to be rebuild with the updated information.

<i>Face culling</i>. Speeds up rendering by making all the backsides of
faces invisible. This doesn't apply to transparent faces.

<i>Ambient lighting brightness</i>. The ambient lighting brightness. The
higher the number, the brighter the ambient lighting. Settings this high
enough prevents the scene from being black at places where there are no
lights.

<i>Lighting quality when not moving</i>. This is the lighting quality that
OpenGL will use when the camera is not moving. This option only has effect
when Lighting is enabled. There are three options:<br>
OpenGL lighting, which uses OpenGL's internal lighting routines.<br>
Basic lighting, which uses QuArK's software lighting.<br>
No lighting, which will disable lighting.<br>

<i>Lighting quality while moving</i>. Same as 'Lighting quality when not
moving', but now when moving the camera. Rendering light can take much
time, especially in larger scenes with many lights. Disabling lighting
when moving will speed up rendering when the camera is moving, and thus
make the movement much less jerky.

Note: Use a utility like <a target="_blank" href="http://www.realtech-vr.com/glview/">OpenGL Viewer</a>
to make sure your video card and video drivers support all the OpenGL
features QuArK needs.
