Decals

Decals are non-tiling image maps that apply directly to objects instead of indirectly using a material. Use decals to modify a limited part of an object’s color, reflectivity, or bumps. Decals consist of a single instance of the image, rather than being tiled as they are when used in a material definition. Some uses for decals include:

Hanging artwork on interior walls. Placing labels or logos on products. Adding signs to the model. Creating stained glass windows.

Note: Decal previews will only display in wireframe views if OpenGL is enabled for wireframe mode. The Pipeline setting must be OpenGL in Options > View > Display Modes > Wireframe > Other Settings > Display Pipeline assignment.

Decal Placement

Add

1. Select one or more objects.
2. On the Edit menu, click Object Properties.
3. On the Properties list, click Flamingo nXt Decals.
4. Click the Add button.
5. In the Open Bitmap dialog box, select a bitmap name, and click Open.

Note

Refresh the image definition

When a bitmap file is changed using an image editor such as Photoshop, you must refresh the bitmap definition in Flamingo nXt.

To refresh the bitmap

On the Flamingo nXt menu, click Utilities > Clear bitmap cache.

1. In the Decal Properties dialog box, select options, and click Place.
2. At the prompts for points, pick points on the model to locate the decal. The precise sequence depends on the type of decal selected: Planar, Cylindrical, or UVMap.

Edit Placement

1. Click the Edit Placement button.
2. At the Select control point prompt, use the graphical editor to change the placement of the decal.
3. Press Enter when finished.

Properties

1. Click the Properties button.
2. In the Decal Properties dialog box, use the controls to change the decal’s properties.

Delete

Click the Delete button.

Move up / Move down

When multiple overlapping decals are applied on a single object, the order in which they are applied may be significant. Decals are applied in the order they appear in the list. The last decal in the list appears to be on top.

Click Move Up or Move Down to change a decal’s position in the list.

To place a planar decal

1. At the prompts, pick locations for the decal’s Width, and Height direction.
2. At the Select control point… prompt, select a control point to adjust the image size, rotation, or location. Or press Enter to complete the decal placement.

Options

Move

Moves the decal. At the Point to move from and the Point to move to prompts, enter any locations as for the Rhino Move command.

UseImageAspectRatio

Restores a stretched decal to the aspect ratio of the original bitmap.

To place a cylindrical decal

1. At the prompt, pick a location for the Center point of the cylinder.
2. At the Select control point… prompt, select a control point to adjust the image size, rotation, or location. Or press Enter to complete the decal placement.

Set or edit the decal placement using the control widget

Note: When using the planar mapping on a curved object, the entire bitmap must lie behind the surface of the object. Portions of the bitmap that lie in front of the surface will not be visible.

To resize the decal width and height at the same time

Drag the control points at the corners of the control widget.

To change the decal height

Drag the center control point on the top and bottom edges of the control widget.

To change the decal width

Drag the center control point on the left and right edges of the control widget.

To move the decal

Drag the control point in the center of the control widget.

To rotate the decal

Drag the x-, y-, or z-axis control point on the widget axis icon.

Decal Properties

The information from the bitmap replaces or blends the object’s color with the decal’s color. This is the most common use of decals.

Projection

The mapping style determines how to project the decal onto the object. It is a good idea to draw construction lines in the scene to help accurately place decals. A rectangle drawn just behind a surface can act as a guide for a standard decal. Use object snaps for accurate placement.

Cylindrical

The cylindrical mapping type is useful for placing decals onto objects that curve in one direction, such as labels on wine bottles. The cylindrical projection maps the bitmap onto the cylinder with the bitmap’s vertical axis along the cylinder’s axis, and the horizontal axis around the cylinder.

Planar

Planar mapping is the most common mapping style. It is appropriate when mapping to flat or gently curved objects. The corners define the bitmap’s location and extents. If the rectangle does not have the same proportions as the bitmap, the bitmap will be stretched or compressed to fit. When using planar mapping on a curved object, the entire bitmap projection must lie behind the surface of the object. Portions of the bitmap that lie in front of the surface will not be visible.

UV Map

Decals using UV mapping are useful for objects like hair and tree bark where the decal flows and stretches to fit the surface. The decal covers the entire object; there is no control over the decal placement. UV mapping uses the u- and v-parameterization of the surface to bend and stretch the image; therefore, no manual placement is necessary.

Browse

Change the image file.

Note

Refresh the image definition

When a bitmap file is changed using an image editor such as Photoshop, you must refresh the bitmap definition in Flamingo nXt.

To refresh the bitmap

On the Flamingo nXt menu, click Utilities > Clear bitmap cache.

Strength

Color

Varies the relative strength of the image color with respect to the underlying material. See also, Material Texture Properties, Color Strength.

Bump

Bump maps create simulated shadows and highlights on the surface. See also, Material Texture Properties, Bump Strength.

Reflective finish

Controls the same properties that are controlled by a material definition. Apply these properties to the specific areas of the object that are affected by the decal. By default, decals have a matte finish.

Intensity

Adjusts the strength of the highlight. Larger values increase the size and strength of the highlight. See Advanced Material Properties, Intensity.

Sharpness

Sets the size of the highlight. Lower numbers specify a broader highlight; higher numbers focus the highlight in a smaller area. See Advanced Material Properties, Sharpness.

Metallic

Sets the highlight color to match the base color. See Advanced Material Properties: Metallic.

Linking options

Specifies how the image file will be linked to materials.

Linked

Creates a link to the image file. The file must be present on the local disk.

Embedded

Embeds the image information in the current file.

Linked and embedded

If the bitmap is found on the disk before rendering, the external file is used. If the image cannot be found on the disk, the internal definition will be used.

Note: To see changes in linked or linked and embedded files go to the Flamingo nXt menu, click Utilities and then click Clear bitmap cache.

Masking

Obscures portions of the image based on either a color value or an alpha channel stored in the image. This allows textures to have complex shaped boundaries and create complex effects such as holes in a surface.

In this example, an image with an alpha-channel background is placed as a decal on a rectangular surface. Masking for materials works the same.

Original decal image. The gray checkered area represents the image alpha channel.

Masking information can come from three sources in the bitmap:

• None
• Alpha Channel
• Color

None

With no masking, the image obscures the underlying material. Masking allows the material to show through the image where the alpha channel or masking color exists. The material assigned to a planar surface in this example has a red base color.

Without masking (left) the image covers the surface, with masking (right), the red material shows through.

Alpha Channel

Uses the image’s alpha channel to define the masked area if one exists.

Original on the left. The gray checkered area represents the image alpha channel. On the right is the image over a water surface.

The alpha channel is a portion of each pixel’s data that is reserved for transparency information. Alpha channels create and store masks that let you isolate and protect parts of an image while you apply color changes, filters, or other effects to the rest of the image. Each pixel in an image is described as channels of data that define the mixture of the red, green, and blue (RGB) colors. The alpha channel is an 8-bit (256-level) grayscale representation of the image that masks the color of the underlying pixel. The value of the alpha mask determines the intensity of the pixel color. If the Alpha channel is 100%, the images pixel will be complete transparent. At other alpha strengths, the image pixels will blend with transparency.

Color

If alpha channel does not exist in an image, a color in the image can be specified as a mask. There is also a sensitivity number to make the mask more or less sensitive to a single specific color as a masked color. Selecting the Color option will activate the Color Dropper, Color Selector, and Sensitivity controls.

Color Dropper

Click to select the mask color from the bitmap. Click on the Color Dropper, then on the bitmap to pick the color. This control is only available when the Color option is selected.

Color

Use the Color Selector to set the main color. See the Color Selector topic for details.

Sensitivity

The value indicates the size of the area around the color that is also masked. Must be greater than 0.0 for color masking to occur. This control is only available when the Color option is selected.

Blur

Partially masks pixels. The value determines the magnitude of partial masking around the masked color. This control is only available when the Color option is selected.

Reverse

Inverts the mask. Pixels that would have been masked are now included, and pixels once included are now masked.

Transparent

Makes the masked area of the underlying object transparent so other objects or the background behind the object can be seen through the object. Normally, the material of the object shows through in that area.

Transparent masking allows a more natural shadow and lets the background objects to show. The underlying material could simply be transparent, but sometimes it is useful to make the surface behind the decal transparent while keeping other areas of the surface opaque.

Show masked colors

Graphically displays the effects of masking as the parameters change. Use the Color Selector provided to select the display color of the masked pixels. Changing this color or the setting of the checkbox does not change the masked color. This is simply a graphical tool for editing the mask.

Advanced

Double Sided

Causes the decal to appear on the back face of the surface on which it is placed as well as the front face.

Mirror

Mirrors the decal image.

Projection direction

Backward

Projects the decal away from the back of the decal image. Front (left), back (right).

Forward

Projects the decal away from the front of the decal image. Front (left), back (right).

Forward & Backward

Projects the decal away from both the front and the back of the decal image. Front (left), back (right).

Transparency

Sets the transparency for the decal. See Transparency. IOR Sets the index of refraction for the transparent decal. See Index of Refraction