2037
Researchers add different operation algorithms to do the filling with these surface units so as to approximate the original CAD model 's skin .
 enabling technology: operation algorithms; concept or principle: surface; material: as; enabling technology: CAD model
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:
 enabling technology: operation algorithms; concept or principle: surface; material: as; enabling technology: CAD model