(5) Transparency
The Transparency item is used to set the transparency of the material. The greater the value, the higher the transparency. When the value is 1, the object will disappear after being rendered due to complete transparency. Under this item, you can also set partial transparency effects as follows:
First draw a black and white painting, as shown in Figure 2, and then save as an image file, in which black represents a transparent part, white is an opaque part. Black and white painting can be drawn with the drawing board in the Windows attachment, or it can be drawn directly under AutoCAD and then copied to the clipboard through the Print Screen on the keyboard, and then pasted on the drawing board for saving.
After selecting the Transparency item and clicking the Find File button, the saved image file is opened, and a transparent texture is obtained. The bitmap adjustment method is the same as the method for setting the material pattern described in step (2).
Partial transparency is often used to express the effect of opening windows (as shown in Figure 3), hollowing out, etc. of the packaging carton. By default, the local transparency effect will be applied to each surface of the carton. However, the window effect is generally designed only on one surface of the carton. In the Adjust Material Bitmap Placement dialog box, click Use Auto Axis. Automatic axis) check box to cancel the hook.
After attaching a material to an object, you can adjust the effect surface of the local transparency effect through the Render toolbar's Mapping button. After clicking the Mapping button, the user will be prompted to select the object first, then the Mapping dialog box will pop up. Click the Adjust Coordinates button, and the Parallel Plane dialog box in the Adjust Planar Coordinates dialog box will appear. Select the surface of the effect of the partial transparency effect.
(6) Refractive index
By adjusting the refractive index of the material, the observation of the scene through the transparent object can be simulated. The sights seen through the glass ball will be magnified and the straw inserted in the drink cup will be staggered in the liquid surface (see Figure 1).
The adjustment of the refractive index is performed by the Refraction item. When the value in the Value column is greater than 1, the concave lens is reduced. When the value is smaller than 1, the convex lens is enlarged. Regardless of whether it is zoomed in or out, the value should generally be within ±0.05, otherwise it will be distorted due to excessive deformation.
(7) Bump Mapping
Bump maps can produce embossed effects similar to embossing or embossed text on the carton surface, as shown in Figure 3. Similar to the local transparency effect, a black and white image file is also saved when the bump map is made (as shown in Figure 4). The black portion will be indented after being rendered and the white portion will be raised. After selecting the Bump Map item in the property bar, the rest of the operation is exactly the same as the local transparency effect and is not repeated here.
3. Attach material
The method of adjusting the material properties through the New Standard Material dialog box is described above. After the above settings are completed, a name is created for the newly created material in the Material Name input box. Click the OK button to complete the new material. Created and automatically returns the Materials dialog. Now that the newly created material is highlighted, click the Attach button to select the object to which the material is attached.
4. Get rendered renderings
After you create a new material and attach it to the object using the above method, you can observe the rendering effect through the Render button in the Render toolbar. It should be noted here that the default rendering type is Render. This method has the fastest rendering speed, but it can't get the effects of pattern, transparency, refraction, and bump. You must select Photo in the Render Type drop-down list. Real (photo-realistic rendering) or Photo Raytrace (photo-level ray tracing rendering) can achieve a perfect rendering effect.
5. Conclusion
In summary, AutoCAD has a powerful material creation function, which enables designers to fully realize their imagination and achieve a more perfect packaging performance through reasonable setting and collocation of various material properties. And AutoCAD material creation method is easy to learn, is a powerful tool for designers to decorate design.
Xu Shujie Wang Youyu Source: Xi'an University of Technology