The background is an important part of the packaging effect map. It is used to set off the theme, enhance the atmosphere, and enhance the artistic expression of the picture.
An artistic design of the background
Different backgrounds will produce different artistic effects. The hue, brightness and pattern of the background mainly depend on the designer's intention of expression.
The background used to set off the package design is generally relatively simple in color, and should not be too bright and bright, so as to avoid distracting guests. Normally, a neutral background such as black, white, and gray is used to set off a colorful package, and a colored background is used to set off a neutral-colored package. In addition, the background used to create the atmosphere is determined according to different customs and people's psychological feelings, such as red and yellow will produce a warm, festive, peaceful atmosphere, suitable for the packaging background of wine and other festive items, and blue to People have a quiet and cool feeling and are suitable for the packaging background of medicines and cold drinks.
In addition to setting the atmosphere and setting the package shape, the background is also used to further publicize the contents of the package and create special effects, such as conveying more information about the contents to consumers through text and pictures, or attracting them with visual impact. Consumer attention and so on.
The design of the background includes two aspects of art design and technical processing. The above briefly introduces the general principles of art design. The following focuses on introducing the setting method of background in AutoCAD from a technical point of view.
Second, the background processing technology
The setting of the background in AutoCAD is done through the Background button of the Render toolbar. After clicking this button, the Background dialog box pops up, which contains 4 types of backgrounds: a monochrome background, a gradient color background, an image background, and a merged background.
Monochromatic background
Select Solid in the Background dialog box, click the AutoCAD Background check box in the Colors column to cancel this option. At this time, the items in the Colors column change from gray to black and you can set the color.
There are two ways to set the color. One is to select the RGB (Red, Green, Blue) color system or the HLS (Hue, Brightness, Saturation) color system in the drop-down menu of the Color System and adjust the color by moving the 3 sliders below it. Another method is to adjust through the selec Custom Color button, click the button to pop up the "color" dialog box, select the basic color, and adjust its red, green, and blue components and hue, brightness, saturation, you can generate the required Monochrome background.
2. Gradient background
The gradient background is made up of two or three color gradients. It is divided into upper, middle, and lower layers. Select Gradient in the Background dialog box to set a gradient background. In the Colors column, click the color patches for Top, Middle, and Bottom, respectively, and then set the colors for the upper, middle, and lower layers as you would for a monochrome background. Gradient background.
In the default state, the width of each color block is horizontally arranged. The height of each color block can be adjusted by the Horizon slider; the Height slider controls the width of the middle color block. When the value is zero, the middle color disappears and becomes Two-color gradient; Rotation slider is used to change the color arrangement angle to generate a rotating gradient background.
Click the Preview button to preview the effect of the gradient color settings.
Image background
The background of the image is the background of the rendering image of the user's pre-saved image file (see Figure 4). In this way, the background can be created as desired. It is the most commonly used background type when designing a packaging effect diagram. The image files that can be used are formats such as .bmp, .jpg, .gif, .pcx, .png, .tga, and .tiff. Select Image in the Background dialog box, first click the Find File button in the Image column, select the image file to be the background in the pop-up Background Image dialog box; then adjust the size, position and arrangement of the image through the Adjust Bitmap button .
4. Merge the background
The merged background uses the last rendered result as the background for this time. This render result includes not only the last set background, but also the user's drawing object, even if the object has been moved or erased in the next render, in the new The object can still be seen in the rendering result because it has been merged into the background.
Merge is selected in the Background dialog, ie using the Merge Background feature settings. However, when using the merged background, it should be noted that this setting is valid only when the previous rendering result is not canceled. If a display control command such as zooming, panning, or the like is regenerated, the screen is refreshed, after rendering. The background will not contain the graphics that were merged into the background after the previous rendering, ie the previous background settings are still used.
5. Background reflection
In any background type, the background color or image can be reflected by the surface of the object, but the object must be given a material with reflective properties. By default, the Use Background checkbox in the Environment column of the Background dialog box is selected, and the rendered object reflects the background. When this check box is deselected and no image file name is entered in the Name input box, the object does not reflect the background. When the Use Background check box is deselected, you can also use the Find File button to specify an image file so that objects with reflective material properties reflect the image specified here without reflecting the background. The reflected background image can be chosen arbitrarily, regardless of the background type, color, and image. However, in order to obtain a more realistic reflection effect, the object is generally reflected directly from the background image.
6. Get renderings
AutoCAD provides three kinds of rendering methods: Render (general rendering), Photo Real (photorealistic rendering), and Photo Raytrace (photo-level ray tracing rendering). Four types of backgrounds can be rendered in any one of the modes. However, there must be a graphic entity when rendering, otherwise rendering does not have any effect. In addition, since the materials and scenes can only be rendered in Photo Real and Photo Raytrace modes, the effect map after setting the background should be rendered in both modes.
Third, the conclusion
In order to obtain a harmonious and unified design effect, various factors need to be comprehensively considered. In addition to considering the relationship between the background's color tone, content, and expression intention, the background and lighting must also be considered. Especially when the background of the image is selected, the lightness and darkness of the background and the direction of the light must be consistent with the brightness and darkness of the light set by the user, so that the whole picture can become an organic whole.
Source: "Printing Technology"