Using MicroStation v8i SS4 08.11.09.829.
I have a DGN file with a GCS in it. I am using a Helmert transformation to define a rotation of -4.7641666 degrees and a scale of 1:500000. The Helmert transformation parameters therefore become:
Helmert A: scale times cos (rotation) = 500000 * cos (-4.7641666) = 498272,4987
Helmert B: scale times sin (rotation) = 500000 * sin (-4.7641666) = -41527,3048
When I attach a Bing Maps layer, the scale looks about correct but the scale doesn't. The rotation is Bing Maps is about 206 degrees (rough estimate).
When using auxiliary coordinates or exporting a KMZ to Google Maps the result is correct.
If I set the rotation to 0 degrees (and therefore Helmert A to 500000 and Helmert B to 0), the Bing Maps raster is correct.
I have a sample DGN if necessary.
MarkSmit said:That's right and that works but apparently it doesn't work well for Helmert transformation if it includes rotation (i.e. Helmert B not set to 0)
I dont understand why you need the transformation at all, if you have a GCS set in your active file, and you follow the instructions for raster attach a Bing map I sent link before ie instructions from Bentley in last post, then the raster will reproject and rotate and transform itself to match the active file gcs and units etc , thats why we use a GCS to allow msnt to do the reprojection / transformations for us..
Lorys
Started msnt work 1990 - Retired Nov 2022 ( oh boy am I old )
But was long time user V8iss10 (8.11.09.919) dabbler CE update 16 (10.16.00.80)
MicroStation user since 1990 Melbourne Australia.click link to PM me
Hi Ajay,
I would like to do so, but I don't see a possibility to insert a file (only a video or image). So if anyone can describe how to do this I will be happy to do so.
BTW I don't have a raster file, I only use the Raster Manager to add a Bing Maps reference.
I just found out that if I reopen the DGN file, Bing Maps is correct.
so your not applying the helmut etc