darkxess 60 Posted April 4, 2011 Ok, so ive gone on to using Global Mapper and as you only import by x y z there is no need for terrain.pbl so what im wondering is how do you set up the hight etc so my map has water? I can see hills and terrain etc came out nicely, but how to lower the map so that the water levels will be correct? Thanks. Share this post Link to post Share on other sites
bushlurker 45 Posted April 5, 2011 (edited) Use a .png greyscale and .pbl file for the first import - it'll go fast since there's no objects and the .pbl will allow you to fine-tune water heights... Afterwards - for subsequent importing you can use XYZ and the heights will remain as they are... Alternatively, you could load your GM xyz output into L3DT and visually set ranges and water levels in there - export from L3DT as a new XYZ, with waterheight set to your requirements, and take it from there... B Edited April 6, 2011 by Bushlurker Share this post Link to post Share on other sites
darkxess 60 Posted April 5, 2011 Use a .png greyscale and .pbl file for the first import - it'll go fast since there's no objects and the .pbl will allow you to fine-tune water heights... Afterwards - for subsequent import/exporting you can use XYZ and the heights will remain as they are...Alternatively, you could load your GM xyz output into L3DT and visually set ranges and water levels in there - export from L3DT as a new XYZ, with waterheight set to your requirements, and take it from there... B So, use the image ive got from universal maps downloader, convert it to the greyscale and .png formats like normal when making a map, then import them to visitor 3 (including the pbl) after that then I import again using the xyz .. that right? Thanks. Share this post Link to post Share on other sites
bushlurker 45 Posted April 5, 2011 (edited) Well... yeah... you got the "use .pbl first time around - just to get yourself an easy set of control parameters to get that water height set" bit right... Not sure about the "converting the map from UMD into a greyscale" though... that's a satellite image - not a DEM... converting it into a DEM is unlikely to work properly... For example... if, on a satellite image you have two fields - side-by-side... one field is full of wheat - it shows light coloured, the other field is ploughed - it'll show dark coloured... Convert that into a greyscale and use it as a heightmap - you'll get high ground (the light bit), beside a pond or lake (the dark bit)... that's not whats actually happening on the ground - far from it... it's just 2 fields - side by side..... In short - you can't make a DEM or heightmap from a satellite image... In a DEM, darkness or lightness is a direct measurement of that areas height... in a satellite image, darkness or lightness is merely a measure of that particular areas optical light reflectiveness... You say you're using Global Mapper? If you have the actual exact realworld coordinates for the four corners of that image area - load the satellite image into GM - specify those four corners... now that image is accurately located in it's Real World location... get it centered on screen - then, hit the "Download Online Data" button and download the SRTM DEM data (or ASTER if available - in the posh new GM versions, I believe) for "Current Screen Bounds"... You'll see a real DEM which matches that satellite image area being downloaded... Now you have 2 layers - one is a photo of what that land looks like from above - the other is a proper "map" of the heights in that same area - and they overlay perfectly... Save the DEM layer only and use it as your Heightfield - save the Sat image and use it as a... Sat layer..... now all you need is to make a mask... Without going into detail... you can make a mask - or the basics of one anyway - either from the Heightmap (predictive modelling - like L3DT's "climates"), or from the actual satellite image (optical image analysis... tricky... ENVI does this sort of thing... probably more trouble - and expense! - than it's worth for our basic purposes... (though you can sometimes get useable mask layers from a satellite image just by fooling around in photoshop - reducing the number of colours, filtering... "select colour range" is a good thing to play with, etc... that's basically what things like ENVI do anyway)... B Edited April 5, 2011 by Bushlurker Share this post Link to post Share on other sites
