1、 Quality classification of machined surfaces
In surface machining, we generally divide the surface into three levels: A, B and C.
Class a surface: this kind of surface is commonly used on all external surfaces of parts in high visibility area, on the dashboard, on the front surface, and on the upper part of the door interior trim panel. The quality of the surface can reach 90% of the high reflective surface. When the feature surface is in the high visible area of the block line (seam line), the curvature continuity of the second-order curvature and above shall be used. The block line of less visible areas or unimportant parts can be used as the first-order continuity.
Level B surface: it is a surface with few visible areas or a better surface that cannot meet the requirements of level A. It is called level B surface by us. For example, the door frame surface, the lower surface of the instrument panel, the ceiling, and the lower half of the door panel trim panel all belong to 95% of the better surface in class B.
Level C surface: a surface with few visible or invisible areas is called a level C surface.
2、 Tools used in surface analysis
Every surface should be evaluated during or after creation. There are many suitable diagnostic tools to review the quality of the surface's interior and boundary, but one analysis cannot be relied on to show all defects. Therefore, these tools are required to combine to complete a thorough review of the surface.
During the review, the following tools will be used:
1. Track highlights to fix or move light sources.
2. Color curvature diagram of solid surface or surface.
3、 Step analysis of surface
1. Render surface: this process is to find abnormal bulges, ripples, distortions or discontinuous highlights. Moving the light source or rotating parts, many initial defects can be identified.
2. Check the control vertex mesh on the surface to determine whether the surface framework is continuous and uniformly varying.
4、 Correction of surface
What if the surface processing does not reach the corresponding level?
When the problem of a surface is determined, a decision needs to be made on the maximum and minimum range of surface reconstruction. And we need to consider whether the time needed to make the modification and the correction have greater value.
Local changes are usually easy to solve, but sometimes small changes will involve the whole patch and most of its surface. Usually, when an initial surface is changed, it will drive the changes of several surfaces. The location of surface defects should also be considered.
If the problem is in a very low visible area or a very rare area, the surface modification can not be done, or more attention can be paid to modifying the surface located in the high visible area.