Thread: City Navigator China 2012.20 NT in English (Offcial Shifted & Venus Shift-Corrected)

Originally Posted by shimsim

Sorry I took so long to post a reply on the map problem I mentioned above. I have attached a picture of my GPS unit showing an example of an area where the map is missing/corrupt. The coordinates are around the area N22.80601 E113.68070. Its a drive a frequently take between Guangzhou and Shenzhen. I have tried different SD card and different unlock methods, but the map errors are always the same.

Thanks for the feedback. This is a known and reported issue that exists in Venus 2012.20 Chinese language version as well. There is no solution to this problem currently.

Here is what happened. The area you gave is right at the (invisible) boundary of two map tiles. Although the boundary looks like a polyline, it is in fact two polygons (one from each map tile) placed side by side seemlessly. The two map tiles are shift-corrected independently. Due to the non-linear property of the shift, the two polygons are no longer placed seemlessly after the shift correction. Worse, for some areas there is a gap between the two polygons. When the center of your screen falls into this gap you will get about half of the map disappeared as shown in your picture. However, the gap doesn't seem to affect routing and navigation, but I still need more feedback to support that. Again, use with caution and at your own risk.