Object Concepts

Combinations of Basic Object Shapes to create complex everyday items

Objects are used to model many shapes in AGi32. The choices of object shapes available are varied and range from simple geometries like rectangles, cylinders (Round-Flat Object) and spheres to customizable shapes with irregular profiles. Objects can be inserted into any environment, both interior and exterior to block, reflect and transmit light as necessary. In addition, single or multiple objects may be stored in a user-defined "library" of objects. Library objects can be recalled at anytime, modified for scale and color or reflectance and be placed in any job file. AGi32 is delivered with a number of factory provided library objects that may be used at any time to add detail, scale and realism to any lighting layout. However, the strength of the system is the ability to create your own object libraries relevant to your work and draw from them whenever necessary.

AGi32 is also capable of importing three dimensional solids created in other software via DXF or DWG files. Imported solids are converted into AGi32 objects and can be manipulated using the object commands. Generally, imported objects are composed of large numbers of small surfaces. These objects can be difficult to edit for color and reflectance once imported. Ideally, an externally created object will be stratified into multiple layers and blocks. This makes the process of assigning color, reflectance and texture relatively simple on import. The internal modelling tools offer substantial flexibility when creating complex elements by using a combination of object shapes. The palm tree object, shown at right, was created by using a Round-Flat object to create the cylindrical trunk and Planar objects to create the leaves. One leaf was created as a template and multiples were added using the Rotate Object and Polar Array Object commands. By visualizing the basic shapes that make up real forms in the environment, you can make your layouts more realistic.

Dialog Defaults

The individual parameters available in all Object dialogs are automatically saved and restored in the Object dialogs. There are two types of defaults present in all of the dialogs: Global and Local. Global defaults occur in every Object dialog and carry over to other Object dialogs as well. Local defaults only occur in specific dialogs. The following defaults are global for all Object commands.

• Label: Default Label is Object. The Label name will automatically increment to produce unique labels. For example, if the first Object is labeled Object, the second is labeled Object_1. When the default label is changed, it will also automatically increment.
• Wireframe color
• Labeling options
• Height of Sides
• Top, Sides and Bottom surfaces: Color, Reflectance and Texture (including applied options).

Reset Defaults - Selecting this button will reset all Global dialog parameters to the factory defined specifications.

 

Object Shapes

Rectangular Barrel Vault Objects
Rectangular Gable Objects
Rectangular Hip Objects
Rectangular Pyramid Objects
Rectangular Flat Objects
Rectangular Flat Object combination
Rectangular Vertical Extrusion Objects
Rectangular Vertical Extrusion Object combinations
Round Cone Objects
Round Flat Objects
Round Dome Objects
Round Sphere Objects
Round Vertical Rotation Objects
Polygon Flat Objects
Polygon Flat Object combinations
Polygon Vertical Extrusion Objects
Polygon Vertical Extrusion Object combinations
Planar Objects 1 - Triangular 2 - Trapezoid 3 - Quadrilateral 4 - Polygon

 

Object Dimensions

All Object types have certain dimensional variables associated that describe some parameter of the shape that must be defined prior to creating it in the graphics area.

Height of Sides- The height of the object sides refers to the distance from the base of the object to top of the object, or the distance between the top and bottom surfaces. This is a vertical measurement in the Z-plane and is specific to the object only, it is independent of the elevation of the object above the floor/ground.

Vault Height - The Vault height is the height of the vault as measured from the top of the walls to the apex or peak of the vault. Vault Width - The width of the vault can be any dimension less than or equal to the width of the object. If the vault width is less than the object width, the vault will be centered in the object. If the vault width is entered as greater than or equal to the object width, the vault will span the entire width of the object.

Gable Height - The Gable Height refers to the vertical distance from the top of the object sides to the top of the gable top.

Hip Height - The Hip Height refers to the vertical distance from the top of the object sides to the top of the Hip. Hip Length - The Hip Length refers to the horizontal distance from the object baseline to the intersection of the hip and top peak as seen in Plan view.

Pyramid Height - Pyramid height refers to the vertical distance from the top of the sides to the apex of the Pyramid. The total height of the Pyramid object is then the height of the sides plus the height of the Pyramid.

Dome Height - Dome height refers to the vertical distance from the top of the sides to the crown of the Dome. The total height of the dome object is then the height of the walls plus the height of the dome.

Height of Cone (base to top) - The Height of Cone refers to the overall height of the cone shape from base to top elevation. This figure is independent of the elevation of the base of the cone. A positive Height will create a conical shape with point upward (above the base). Whereby, a negative Height will place the point of the cone shape downward below the base. Regardless of whether the cone is pointing up or down, the current Z-coordinate specifies the base elevation when creating the cone shape in Plan view. If a cone shape is to be trimmed between the base and top elevations the Height of the Cone will dictate the slope of the cone sides and must still be entered as the height to the imaginary cone top.

Height of Trim (base to trim) - The Height of Trim refers to the height of the cone shape from base to the trim line. The Trim Height must be less than the Cone Height. Cones can be trimmed anywhere in between the base and tip. This creates a conical shape that does not terminate in a single apex point. Note: If the Cone Height is negative (cone points down) and you wish to trim the cone, the Trim Height must be negative as well.

Height = Radius - The Height of the sphere refers to the vertical distance from sphere center to apex. If the Height = Radius radio button is selected, the height will be equal to the radius as specified parallel to the X-axis. If the Aspect ratio is equal to one, this setting will always result in a perfect sphere. Height (from center point) - The Height of the sphere refers to the vertical distance from sphere center to apex. This distance can be specified independently of the radius dimension allowing shapes to be flattened or elongated in the Z-direction. If the Aspect ratio is equal to one, the object will always be circular when viewed from above (Plan). Aspect ratios other than one will elongate the shape in either the X or Y dimensions.

Aspect ratio - The Aspect Ratio is used to define the shape of the sphere equator. An Aspect Ratio equal to one will create a perfectly round spherical equator. Aspect Ratios greater than one lengthen the X-axis of the base resulting in an elliptical shape left to right. Aspect ratios less than one elongate the Y-axis of the base to form an ellipse aligned top to bottom. As an example, an Aspect Ratio equal to two will create an ellipsoidal object that is twice as long in the X-dimension as it is in the Y-dimension. An Aspect Ratio equal to one half (.5) will create an ellipsoidal equator that is twice as long in the Y-dimension as it is in the X-dimension.

 

Surface Properties

Surface properties of Color and Reflectance must be defined for all object surfaces. Color and Reflectance are related to one another in a way that allows only certain colors to be assigned to a specific reflectance value. This is a mathematical relationship that is discussed in more depth here. To alter the color or reflectance of an Object surface, click the mouse in either the color or reflectance cell.

By default, the colors shown are shades of gray based on the reflectance entered in the adjacent cell. You can select any reflectance within the gray scale range (Black to white) by entering it in the reflectance cell provided.

To select a color, move the Hue slider to the desired color, then move the Saturation and Luminance sliders to achieve the desired color. The reflectance will be calculated and displayed. You can adjust the reflectance within the Hue by moving the reflectance slider.

 

 

Textures

Texture are graphic images that may be applied to the object surfaces to make them appear more realistic. Textures like brick, stone, concrete and wood can be tiled in a repeating pattern across the surfaces or stretch across them. The average reflectance and color of the texture is calculated and used instead of the surfaces original color in the radiosity calculations.

AGi32 comes with a selection of assorted textures that may be applied to any surface. You may also obtain textures from lots of other sources, including free texture sites online, commercial texture collections, even use your digital camera to obtain them directly. Click here to read about texture tips.

To apply a texture to a surface, click in the Texture cell. Select the texture from the Texture database, then determine the application options.

 

Advanced Surface Properties

Open/Closed Objects

Certain round object types, such as cones, spheres and vertical rotation shapes can be Open or Closed and can reflect light on the outside or inside. In the case of transmittance >0, the object will have reflectance/color on both inside and outside unless "closed."

Open Shapes

When the Open option is selected, the object base is removed (for cones and vertical rotation objects) and any partial sides are also left open. Open objects may be closed at a later time by editing the object and unchecking the Open selection box.

Reflective Side

When working with open shapes, reflectance/color can be specified to be on either the inside or outside of the object. Generally, it is imagined that "open" shapes will be reflective on the inside or will be assigned a transmittance. "Closed" partial shapes would most likely be reflective on the outside only.

 

Inserting curved surfaces into object (Polygon-Flat, Polygon-Vertical Extrusion, Planar, Rectangular-Vertical Extrusion and Round-Vertical Rotation)

It is a simple procedure to describe a curved surface using an integrated Arc function. An arc can be fit between any two points and can be of most any radius. To insert an arc into a building, press the F4 key on your keyboard at the starting point of the arc. The command prompt (lower left corner of screen) will then prompt for the second point of the arc as shown at right. Click the mouse at the second point of the arc and a dotted line will appear showing the current arc shape. If you don't move the mouse the initial arc will be a perfect semi-circle (#1). Move the mouse cursor toward the arc apex to raise the arc center point and increase the circumference (#2).Or, move the cursor away from the apex of the arc and move the arc center downward. This effectively flattens the arc (#3).

Reversing the Arc

The direction of the arc can be reversed by simply pressing the F5 key on your keyboard.

Curved surface resolution

Curved surfaces are automatically divided into a series of straight segments based on the setting of the system variable Initial Curve Increment (degrees). The default is 15 degrees. This is adequate for most applications. This variable can be found under System Settings command from the Tools menu. Click on the Defaults tab and then on the Advanced button.

 

Removing Surfaces

AGi32 provides the ability to eliminate surfaces from any object shape you might create by removing the surfaces. Removed surfaces are not considered in the calculations any longer. A removed surface behaves differently than one whose reflectance is set to zero. Surfaces that have zero reflectance absorb all light that touches them and reflect no light outwards. Removed surfaces allow light to transmit directly through them because they no longer exist (unless another surface exists in the same location). Once surfaces are removed, you can recreate them by changing their reflectance to a real value.

By removing selected surfaces in the object, you have the ability to append other shapes to the object. These shapes may in turn have their surfaces removed. Continuing in this fashion, you can create very elaborate models consisting of numerous objects joined together. For example, you may want to create an Rectangular-Flat object and remove one of the sides that was initially created to create the base for a bookcase. Once the side is removed, you can use any combination objects to create a custom shelving unit.

To remove a surface, either Edit the object and select the Surface Edit button in the Edit dialog or use the Surface Edit command to select the object. In the Surface Edit dialog, navigate to the surface you wish to remove. To remove more than one surface in an object, Tag all of the surfaces you need to operate on. Change the Surface Type to Removed (Invisible) and click Ok.

The surfaces will be removed from the environment. In Model Mode, they will appear as dashed lines, in Render mode, they will simply not appear. Removed surfaces can be replaced at any time through the Surface Edit dialog by changing the surface back to a Single Sided or Double Sided surface with appropriate reflectance/color.