2151
The design and types of the volumetric gradient can be classified according to 1D , 2D and 3D , and distribution of materials uniformly or through special patterns .
 engineering feature: design; material: be; concept or principle: 2D; concept or principle: 3D; concept or principle: distribution; concept or principle: materials
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: manufacturing standard, machanical property, manufacturing process, material, engineering feature, process parameter, machine or equipment, application, process characterization, enabling technology, biomedical, concept or principle 
Text: {0} 
Answer:
 engineering feature: design; material: be; concept or principle: 2D; concept or principle: 3D; concept or principle: distribution; concept or principle: materials