Vector transparency in 3d

Ice Age MarkIce Age Mark Global Mapper UserPosts: 324Trusted User
edited June 2011 in Vector Data
Hi there Mike,

I have the NHD flowline of a river and two major tributaries. I load DEM data under the three flowlines and give them the elevation of the underlying terrain. Then I turn off the DEM layer and view it in 3D with a 50X vertical exaggeration (small total relief vs. large geographic area). This makes a really cool "CAT- SCAN" like image that can be rotated, zoomed, etc., to see the vertical as well as the horizontal relationships of the river system.

So next, I get the idea to have some kind of a vertical reference in the 3D view, and I try to create several semi-transparent horizontal area features at different altitudes encompassing the area of the view. This doesn't seem to work as expected because, no matter what the transparency settings of the area features are when I create them, they are always opaque in the 3D view. I had hoped to see the 3D flowlines through the area features, and the points where the lines intersect the planes from any angle.

Must it be this way? It seems that if vector areas can be transparent for raster imagery in 3D, solid vector lines could be visible through semi-transparent vector areas. If this can't work, is there a better way to accomplish displaying some kind of a vertical scale in 3D? (Could the flowline itself be color-coded for altitude, sort of like a shader?)

No hurry on this, I'm just fooling around.

Thanks in advance,

Mark

Comments

  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited June 2011
    Mark,

    There are some oddities in how translucent 3D areas are displayed in the 3D view. For some reason only some end up being see through. I have a couple of thoughts though. Can you save your 3D data (including translucent areas) to a file or workspace and post that, then I can see if I can figure something out?

    Thanks,

    Mike
    Global Mapper Support
    support@globalmapper.com
  • Ice Age MarkIce Age Mark Global Mapper User Posts: 324Trusted User
    edited June 2011
    Hello again,

    I attached my workspace file. I hope that's what you meant and it worked.

    The 3D image is a real brain twisting sight, because the area features are transparent with respect to each other, but not to the line features crossing them. The bottom layer (purple-500')was intended to be opaque.

    Also notice the diagonal shading line on the planes. It seems to perhaps be related to the fifth point created to "close" the area feature.

    If you need more/different info, let me know.

    Thanks,

    Mark
  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited June 2011
    Mark,

    Thanks, good news, I was able to re-arrange the drawing so that the lines can show through the translucent areas in the 3D view. I have placed a new build at http://www.globalmapper.com/global_mapper12.zip with the change for you to try. Simply download that file and extract the contents into your existing v12.xx installation folder to give it a try. If you are using the 64-bit v12 version there is a new build at http://www.globalmapper.com/global_mapper12_64bit.zip .

    Let me know if I can be of further assistance.

    Thanks,

    Mike
    Global Mapper Support
    support@globalmapper.com
  • Ice Age MarkIce Age Mark Global Mapper User Posts: 324Trusted User
    edited June 2011
    Thank you very much sir. The 3D view works as I had hoped now and I can fine-tune it. [I've already found that translucent white (25%) "elevation levels" with a black background looks much better.] Also, thanks for the subsequent GeoPDF fix; I had just made a Geotif GeoPDF mosaic of the subject area and was noticing those tile seams. I'll upgrade again.

    Sincerely,

    Mark
  • Ice Age MarkIce Age Mark Global Mapper User Posts: 324Trusted User
    edited June 2011
    Mike,

    Per your request, here is my workspace file again. It was too big to e-mail, so I re-posted it here.

    If you need any other info or input, let me know.

    Mark
  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited June 2011
    Mark,

    I hadn't noticed the diagonal line either until you pointed it out. Apparently when you draw a polygon it is automatically broken into triangles by OpenGL and then when those are translucent some strange rendering happens. I'm not sure that I have an easy solution for this one.

    Thanks,

    Mike
    Global Mapper Support
    support@globalmapper.com
  • Ice Age MarkIce Age Mark Global Mapper User Posts: 324Trusted User
    edited June 2011
    Hello there,

    I've heard of OpenGL, but I don't know what it is. It sounds like it's something within GM that you don't have control over the inner workings of. If it can't be fixed, so be it. If you think of a way, let me know. As I mentioned, I think being able to produce a good basic block diagram for slide shows and web pages from actual GIS data and imagery would be an asset to GM.

    I've had some success with a "user created grid" made with only lines, instead of the horizontal translucent area feature, for a vertical reference. It's pretty cluttered though, and only solid lines seem to be able to be rendered. One advantage though is that I can set it up so that the grid reflects 7.5 (or other) quadrangle boundaries.

    Thanks for your time and help on this. If anyone else has any ideas or suggestions, pipe up.

    Sincerely,

    Mark
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