ensta Posted October 2, 2020 Share Posted October 2, 2020 (edited) Hi, Thinking of investing in a s/h copy of VW2015 from the trading pages here. Can people confirm it's "lag free" in it's operation? Any other considerations to be aware of? Am on PC. Basic mapping work over aerial images is what I'll be doing with it. Also, is there a transfer fee? Cheers, Edited October 3, 2020 by ensta went off topic Quote Link to comment
Art V Posted October 3, 2020 Share Posted October 3, 2020 (edited) Not knowing from which country you are, but generally there is no transfer fee. The seller needs to inform his/her distributor that the license has been transferred to you (including your contact information like name, address etc.) so that the distributor can register the change and you will be able to upgrade at some point if that would be possible to upgrade from VW 2105. You may want to check that as well if you intend to upgrade at a later time, otherwise you will have to buy a newer version later on. Also ask if the license is activation based or dongle based, this can vary by country if it is a localized version of VW. VW2015 is "lag free" in the sense that the tools don't have lag in the meaning of slow to respond to input etc. However, depending on what you are trying to do newer versions may be faster in processing the information due to improvements in the graphics engine etc. The same applies to newer functionality etc. in later versions, you may want to check if newer versions have functionality that you need. Do check if your PC does meet the hardware requirements for using VW2015. Generally speaking VW2015 will be fine if it does what you want to do. E.g. later versions of VW have the EPSG catalog implemented which is very useful if you want to use the GIS funtionality with regard to coordinate systems. If you don't need this GIS functionality/coordinate systems then it is not an issue. With regard to coordinate systems, there was an issue with a VW version, I think 2015 or 2016 but would have to look that up, not honouring the false easting of the UTM coordinate system causing an offset of 500km to the west of the coordinates but upon export that offset was added back so the export would be at proper coordinates again. However within VW the coordinates would be incorrect, adjusting for that by shifting the content or the origin would add this correction on top of the exported coordinates and then the coordinates in the export would be 500km off to the east. There is a way to solve this by manually setting the coordinate system parameters. Again, if you are not using this now or in the future then it is a non-issue. So in general VW2015 is just fine, apart from the GIS issue with the false easting outlined above there are no major showstoppers that I can remember and I have used it for large GIS related projects and 3D modelling etc. without issues. One thing to keep in mind with aerial/satellite images, but this applies basically for any VW version after 2015 as well, is that with large images you may want to split the image in tiles and then import those tiles. If the tiles are georeferenced then you can use the free QGIS to create georeferenced tiles, save them as geo jpeg images of approx. 400 megabytes maximum and then import those into VW, they should then align automatically instead of having to align them manually. That way you can import e.g. 25 gigagbyte images in VW without too much hassle. Importing it as a single image may either fail or take a very long time. Edited October 3, 2020 by Art V Quote Link to comment
ensta Posted October 3, 2020 Author Share Posted October 3, 2020 Wow, thanks for your lengthy post. Very thoughtful The lag issue I'm concerned about is that which is reported for later versions where panning and zooming is really slow This I am very keen to avoid With regards to workflow, images come in via a dwg import These dwg files are created through an AutoCAD plug-in that links with Google Earth and Bing Background maps are single images and not big typically, just Max res Google Earth images. Maybe 20 Meg Currently there's no option to produce tiled images Many thanks again for your thoughts Quote Link to comment
Art V Posted October 3, 2020 Share Posted October 3, 2020 (edited) 14 minutes ago, ensta said: The lag issue I'm concerned about is that which is reported for later versions where panning and zooming is really slow This I am very keen to avoid This is definitely NOT the case for VW 2015, it does not have that specific lag issue. The latest SP for VW2017 or VW2018 basically solved that lag issue. 15 minutes ago, ensta said: With regards to workflow, images come in via a dwg import These dwg files are created through an AutoCAD plug-in that links with Google Earth and Bing Background maps are single images and not big typically, just Max res Google Earth images. Maybe 20 Meg Currently there's no option to produce tiled images In that case VW2015 should be just fine. What I forgot to mention above is that the GIS functionality in VW2015 exists in VW Landscape and to some extent also in VW Architect. If you are looking at VW Fundamentals then it won't have that functionality if I remember that correctly. So if you do need georeferencing etc. then VW Landscape is probably the version to get unless you are more on the architectural side. Edited October 3, 2020 by Art V Quote Link to comment
ensta Posted October 3, 2020 Author Share Posted October 3, 2020 When you say georeferenced, is that just having the coordinate system? All imports are to scale and georeferenced already. So, would any exports back to ACAD need to have this intact? Quote Link to comment
Art V Posted October 3, 2020 Share Posted October 3, 2020 (edited) 21 minutes ago, ensta said: When you say georeferenced, is that just having the coordinate system? Not necessarily, georeferencing also contains projection information, i.e. it will "reshape" the image to represent the curved earth surface in a flat surface as closely as possible. Different CRS's (CRS=Coordinate Reference System) can have different projections etc., you can often see this when switching from one CRS to another and you may notice a change in the image because there will be some "shifting around". Often the difference is small on screen but when drawing you'll notice that the coordinates will be different. This could be centimetres but it could also be more. 21 minutes ago, ensta said: All imports are to scale and georeferenced already. In that case it is really important that you know what the scale is in the AutoCAD drawing so that you can import at the same scale. Mandatory in that case is also to import the drawing as aligned with internal origin so that there will not be a coordinate shift when importing and exporting back. Another thing to check is the UCS in the ACAD file, if it is rotated relative to World UCS then you may get incorrect imports because VW tends to import relative to World UCS. I don't think VW will be able to read georeference information from DWG files, if present at all, so if a CRS has been implemented then you will also need to know which CRS and set that as the CRS in VW. It could also be that they just imported the image, scaled it and set the origin of the UCS in a way that you get the coordinates, or they may have moved the image at coordinates. Either way you need to receive reference points for the coordinates if those are not present in the Acad file. In that case you don't need the GIS functionality and just export it back to DWG. Edited October 3, 2020 by Art V Quote Link to comment
unearthed Posted October 4, 2020 Share Posted October 4, 2020 AFAIK vw can only read the information in the associated .jgw (that usually comes with an image/raster file ) .jgw files hold the real-world location coordinates and orientation for the centre of the top left pixel. Normally a dwg/dxf file will have an associated raster file, along with a jgw file which is simply a .txt file, which looks something like this: 1.000000 0.000000 0.000000 -1.000000 263111.187500 4375666.000000 where the bottom two lines are the upper left pixel coordinates. there is an app out on the web createJGW.exe which will read/parse an image and create .jgw's (I think it will do batches of tiles too), altho' they can also be written by hand Quote Link to comment
Art V Posted October 4, 2020 Share Posted October 4, 2020 33 minutes ago, unearthed said: AFAIK vw can only read the information in the associated .jgw (that usually comes with an image/raster file ) That would work if the georeferenced file is attached to the DWG file as a referenced file, which means the georeferencing information would then be available through the related world file (jgw/tfw). Based on the response by @ensta it looks like the image file will be embedded into the dwg file and then the georeferencing information will only be in the dwg file itself. VW2015 cannot read that georeferencing information of a dwg file, haven't tried with VW2021 so far as I don't use dwg a lot for GIS development (i.e. doing all the GIS stuff in DWG) but I doubt VW2021 would be able to read that info either. Though in theory it should be possible to extract the georeferencing/CRS from the DWG file when importing into VW, but that requires VW developers to implement this in VW's GIS functionality. Quote Link to comment
unearthed Posted October 4, 2020 Share Posted October 4, 2020 I don't work directly with .dwg much nowadays, and didn't know ACAD allows image embedding. Seems the file is parsed to become a new format inside the .dwg. Seems there's a way to extract/remake the raster but would need ACAD, or BricsCAD or similar - sounds a palava. https://forums.autodesk.com/t5/visual-lisp-autolisp-and-general/extract-embedded-images-from-autocad-drawing/td-p/5900562 Quote Link to comment
zoomer Posted October 4, 2020 Share Posted October 4, 2020 AFAIK in Bricscad the embedded images come in but there is no way to get them out to edit or exchange them. Quote Link to comment
Art V Posted October 4, 2020 Share Posted October 4, 2020 1 hour ago, unearthed said: I don't work directly with .dwg much nowadays, and didn't know ACAD allows image embedding. Seems the file is parsed to become a new format inside the .dwg. Yes, they often become OLE objects, which are sometimes difficult to get out of the DWG file in a decent quality. The default behaviour is to attach images as a referenced file, and that is how most people do it. But it is possible to embed images through OLE, depending on the original quality and how it is added the quality could be fine or just lowres compared to the original. Quote Link to comment
Art V Posted October 4, 2020 Share Posted October 4, 2020 1 hour ago, zoomer said: AFAIK in Bricscad the embedded images come in but there is no way to get them out to edit or exchange them. One way to get an embedded image out, if it is a OLE image, is to copy the image and paste it in an image editing program assuming you don't have a copy of the originating program from which the image was coming. The quality may be poor though. Quote Link to comment
unearthed Posted December 22, 2020 Share Posted December 22, 2020 Just found this, may be useful for programmer types to chase up way to extract raster/ image information from OLE files; python-oletools: a package of python tools to analyze OLE files, apparently partly written for forensics on MS files but appears to be applicable to OLE's in general. Quote Link to comment
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