Global Mapper v25.0

Hillshading

redbeard
redbeard Global Mapper UserTrusted User
edited July 2009 in Elevation Data
I'm wanting to make a hillshading layer, one that is mostly transparent and lies on top of some DRGs.
For example, you take a DRG like this and I want it to become something like this

My desire is to have this as a separate layer that I can toggle on and off as an overlay, much like the NGS TOPO! state series product.

Does anyone have any ideas on how to go about this? The resulting layer by itself probably wouldn't look like much.

So how do I go about this? I've tried a few hillshading options, but I can't seem to produce the desired result.

Comments

  • global_mapper
    global_mapper Administrator
    edited July 2009
    You can easily do this by first loading an elevation layer (like perhaps the NED data from the File->Download Online Imagery menu command), then loading your DRG and using the following steps from the FAQ:

    Question: How do I drape raster imagery (i.e. DRGs or aerial photos) over elevation data (i.e. DEMs)?
    Answer:

    To drape raster imagery over gridded elevation data, first load the elevation data, then the raster data. Open the Control Center (found on the toolbar and under the Tools menu), highlight the raster image(s) you want to drape, and select the Options button. Select the Texture Map option and press OK. The raster image(s) should now be draped over the elevation data and shaded. Note that you will have to have hill shading enabled in order to see any difference (this is the rightmost button on the toolbar).

    Let me know if I can be of further assistance.

    Thanks,

    Mike
    Global Mapper Support
    support@globalmapper.com
  • redbeard
    redbeard Global Mapper User Trusted User
    edited July 2009
    I'll have to try this again tonight. But what I'm looking to create is just a hillshade layer that is completely transparent on the sun side, and mostly transparent on the shade side. I intend to export as tiles for a web app I'm making for times when I have no internet access. I then can add this overlay to my basemap (of topo maps), thus enable me to turn the hill shade off.
  • global_mapper
    global_mapper Administrator
    edited July 2009
    Providing hill shading (texture mapping) to a raster layer will basically just darken a loaded raster layer in shadowed areas and have no effect on the sun-shaded side, so I think it will be what you want.

    Let me know if I can be of further assistance.

    Thanks,

    Mike
    Global Mapper Support
    support@globalmapper.com
  • redbeard
    redbeard Global Mapper User Trusted User
    edited July 2009
    This is like what I want, but is there a way to lighten the dark areas? The shade is dark enough that I can't see any of the map info, it's just black.

    Is there a way to get this texture in a separate layer so I can adjust the transparency and make it an overlay so I can turn it on and off?
  • global_mapper
    global_mapper Administrator
    edited July 2009
    You can control the maximum darkness level of shadows on the Vertical Options tab of the Configuration dialog.

    There is not currently any way of getting this as a separate layer, other than perhaps loading in an all white image and texture mapping it, then saving that out to a file for use as a translucent layer elsewhere.

    Let me know if I can be of further assistance.

    Thanks,

    Mike
    Global Mapper Support
    support@globalmapper.com
  • redbeard
    redbeard Global Mapper User Trusted User
    edited July 2009
    I seem to have made some progress. I'm using the slope direction shader and I set the South and West colors to black and the North and East to white (sun in the NE sky, I may change to NW), and made the white the transparent color. I then changed the translucency to ~10%. But currently it only seems to look the way I like using srtm, so I must have changed something else that I can't remember as I'm trying to do this with the NED and it's not the same.

    But either way, I'm got a fake shade so far. Does anyone have any ideas on other ways to tackle this?

    Is there a possibility to add a "shadow" hillshader to the dropdown options? Maybe I'll just post that in the suggestions part of the forum.
  • global_mapper
    global_mapper Administrator
    edited July 2009
    For a "shadow" hillshader you could just use the Daylight Shader and set the color to white on the Shader Options tab of the Configuration dialog. Then the elevation layer should be a white layer (which you can make transparent) with variable darkness where the shadows are. You can setup the sun angle and other options on the Vertical Options tab of the Configuration dialog.

    Let me know if I can be of further assistance.

    Thanks,

    Mike
    Global Mapper Support
    support@globalmapper.com
  • redbeard
    redbeard Global Mapper User Trusted User
    edited July 2009
    That does do what I need. Thanks!

    I'm still learning Global Mapper, and it seems to work quite well.