Sets cutoff distance, in twips, when repainting ghost images. When the distance moved is greater than the cutoff value, the image is not repainted.

Sets the cutoff for determining whether the complete ghost image will be seen or a cube covering the image's extents.

Sets cutoff for determining whether complete 2D ghost Images will be displayed or partial images.

Sets increment step for entity list if number of entities exceeds Ghost 2D Image - Number of Entities Cutoff.

Sets the initial curve increment in degrees. Changing this parameter does not effect existing entities.

Sets the number of selection lines per line of text. Changing this parameter does not effect existing text entities.

This setting specifies the minimum testing footcandle value required to determine whether the contribution from a luminaire is considered. The maximum candela value is used to test the contribution of the luminaire initially. If the contribution is equal or greater than the limiting value, a real calculation is applied.

When in Surface View Mode, either directly or by creating an Opening, only entities that are located within the tolerance are displayed.

Text factor is applied when importing or exporting CAD files.

Offset factor is applied when importing or exporting CAD files.

This setting will flip an entity color to the opposite color if the difference between the RGB components of the entity and the RGB components of the background is less than the Flip Color Tolerance. This setting is intended to keep entities from disappearing against the background if they're the same or nearly the same color. For example, on a black background, black entities are mapped to white, and dark blue to light yellow. The higher this setting, the lesser the tolerance (more colors flip).

This setting specifies the initial tolerance distance (in the current units - ft, meters, inches or mm) for drawing entity endpoints to be selected as potential Snap To points. If several Snap To points are available within the initial tolerance distance, the closest point to the current cursor location becomes the actual Snap To point. The default initial tolerance distance is 2. Increasing this value increases the potential Snap To points.

This setting determines the final tolerance distance (in current units) to the drawing entity endpoint from the cursor for it to become the actual Snap To point. In the case where several potential Snap To points are within reach of the cursor, this setting determines which is closest. The default setting is .05. In very small detailed environments, this value may need to be decreased in order to select the appropriate Snap To point.

This section specifies the initial discretization of all surfaces in rooms and objects and Diffuse Window Transition  surfaces. The mesh level is based on the longest side of each surface. Decreasing the patch size increases the number of patches and elements and lengthens the calculation time, may increase accuracy.

This section specifies the initial discretization of Transparent Window and Daylight Opening Transition  surfaces. The mesh level is based on the longest side of each surface. Decreasing the patch size increases the number of patches, lengthens the calculation time and may increase accuracy. Note: Only Patches are used in these Transition surface types, Elements are not included (reflected light is not considered).

This section specifies which patch and element levels (from the Variable section) to use when discretizing poles, pendants and luminaire symbols.

This setting allows you to specify the maximum discretization level for luminaires. The default value is 1 foot. Point sources are not discretized. By default, luminaire subdivision occurs based on closest element proximity. If luminaires subdivision is forced (see row below), all luminaires are subdivided when applicable regardless of surface geometry.

Luminaire Subdivision only occurs when there are room and/or object surfaces defined (surfaces must be on - not Frozen, Removed or Off in Project Manager).

This setting forces luminaire to subdivide to specified size regardless of surface proximity. Subdivision occurs along and across the luminous box producing a rectangular array of sources.

The absolute maximum number of subdivisions for each luminaire is 16 in each direction regardless of specified size, this results in a maximum of 256 sources (16x16). For example, if the Luminaire Subdivision value were set to 0.1, a four foot by one foot luminaire would only be subdivided into 0.25 foot pieces (4/16). The subdivision level applied along the maximum dimension is also applied to the opposite dimension so that a point source summarizing a box is created. This option should be used with caution, as forcing luminaire subdivision will increase calculation time particularly when raytracing direct illumination. Luminaire subdivision increases the number of luminaires, which increases calculation time.

Secondary light sources (secondary sources) reduce the occurrence of surface mottling which can occur by light emitted from bright patches to small elements.

Secondary sources are disabled by default. When enabled, secondary sources are ‘activated’ only if both of the following situations occur:

• One or more patches in the environment emit a Threshold value of the Total or Average Luminous Flux in the environment. The default threshold value is 0.01 (or 1%). If the threshold value if too high (e.g. 0.1), none of the patches will be enabled as secondary sources. If the threshold value is set too low (e.g. 0.0001), too many patches will be considered as secondary sources which would have an adverse affect on calculation time. As a general rule of thumb, threshold value should never be increased, it may be necessary to decrease the threshold value to achieve optimum results.
• There are elements receiving light from these patches that are small enough to require ray tracing when the radiosity step is calculated. Small elements are encountered if the elements are quite a distance from the patch or the elements were created by adaptive subdivision. As a rule of thumb, the projected area of the element must be less than approximately 0.5 degree for ray tracing to occur.

When these conditions exists, the first bounce of light from the patches that meet these requirements will be ray traced to the elements, instead of being calculated by radiosity algorithms. Ray tracing secondary sources can increase calculation times significantly, as the number of steps increases; however, the visual results are more aesthetically appealing and smoother than mottled surfaces.

Each additional secondary source ray trace will add an additional step to the total radiosity calculations. Users can tell if a secondary source calculation occurred by comparing the number of steps in the Calculation Summary dialog with and without secondary sources enabled.

• For non-daylight environments (interior and exterior), Average Luminous Flux is approximated by taking the total amount of light (luminous flux) emitted by the luminaires divided by the total number of luminaires.
• For daylight environments (interior and exterior), the Total Interior Luminous Flux or Total Exterior Luminous Flux is used.

These situations may require a necessary decrease in the Secondary Sources Threshold value

• A small patch of daylight is present in an interior simulation and the patches caused by electric light sources are not being used as secondary sources (because the daylight patch increases interior flux so high that electric light sources are not considered as secondary sources).
• Significant surface mottling is still observed with tight adaptive subdivision settings.
• Electric light sources are not emitting the same flux values and secondary source considerations are required of lower flux emitting luminaires (e.g. gelled sources or lower lamp wattages).

Note: Secondary Sources are also applied to Direct Flux Only surfaces when enabled, except for Roadway pavement surfaces. To utilize a Direct Flux Only surface as only considering Direct Flux, Secondary Sources must be disabled.

This setting specifies how surfaces with Automatic Placement calculation points are meshed. Surfaces with Automatic Placement points are meshed finer than surfaces without points. Note: Only General Surface Types respond to Smart Meshing.

Coplanar Polygon Meshing is the process where surfaces that lie in the same plane, in the same object, with the same properties are 'merged' into a single surface. This reduces the number of surfaces and minimizes shading discontinuities between adjacent surfaces. This process may produce undesirable or unexpected results when the merged surfaces have different initial mesh properties (resultant mesh may be less than expected). If this occurs, simply disable coplanar polygon merging.

Hardware Acceleration can affect the appearance of the rendered environment. Sometimes changing this setting will improve the image.

Hardware Acceleration can affect the appearance of the graphics in some dialogs, such as Roadway Optimizer and the CAD Viewer. Sometimes changing this setting will improve the image.

If enabled, Transition Surfaces are treated as Daylight Portals. This currently has no effect on the calculations. Daylight Portals will be implemented in a future release.

Multi-Thread processing is available for the following calculation types when using Full Radiosity Method: Virtual Meter Illuminance, Daylight Factor, and UGR. Multi-Thread processing is not available with Direct Only Method or with the following calculation types: Exitance Meter Illuminance, Exitance, and Luminance

For computers with two or fewer available threads, engaging Multi-Thread processing may actually increase the calc time. Therefore, AGi32 first checks the number of available threads and then proceeds with the calculations based on which of these settings is selected:

• Auto (default): If the number of threads < 4, multi-thread processing s NOT used for calc points. If the number of threads ≥ 4, multi-thread processing is used for calc points.
• On: Multi-Thread processing is used for calculation points, regardless of the number of available threads.
• Off: Multi-Thread processing is not used for calculation points, regardless of the number of available threads.

The Gamma Factor adjusts for the non-linearity of phosphor excitation in computer monitors. A computer monitor displays colors by exciting phosphors on the screen. Since phosphors are not excited linearly, when the computer reads a luminance value from the rendered image and sends it directly to the monitor the displayed luminance will be less than the calculated luminance. The actual Gamma Factor varies between makes and models of monitors but in general, a value of 2.2 is used.

The Anti-Aliasing Sampling Level allows the user to automatically apply anti-aliasing to the rendered images in Render Mode. Anti-aliasing is a software technique used to make jagged edges in images appear smoother. By overlaying the original images with slightly offset copies, the eye is fooled into seeing straighter lines and smoother curves (instead of “jaggies”). The Sampling Level indicates the number of image copies applied and offset from the original image.

Anti-Aliasing is enabled by default (check box) and set to 8 samples. The Maximum Sampling Level is 15. Higher sampling levels increase the image quality but also take longer to produce.