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dchall8
449 post(s)
#18-May-18 16:45

I'm putting this suggestion here in the forum to see if the idea gets any traction. It might be technologically impractical, but if not it might be a great tool.

It is hard to know in advance which azimuth, altitude, and Z scale work best for the surface you're looking at. The current approach for setting the hillshade on a DEM is to type values for azimuth, altitude, and Z scale into the form and select Update Options to see the change. This suggestion is for a sundial type of tool with a single handle which could be dragged around to change the azimuth. The direction of the dial would change the azimuth, and the length of the tool would change the Z scale. That leaves altitude. I'm drawing a blank on that, but maybe something could be done with the Ctrl key and maybe the mouse wheel. But key to this idea is to have live preview of the effect of the changes. This would allow the user to see changes live without typing the numbers 360 times times the altitude and Z scale possibilities.

If this is not possible I'll go back to my corner, but I thought it might be worth a mention to get the creative juices flowing.

KlausDE

6,181 post(s)
#18-May-18 22:33

Perhaps the attachment in this very old thread shows a direction (mfd8)

Mind the correction at the end of the thread.

geozap73 post(s)
#19-May-18 07:05

To have such a tool wouldn't be bad.

Regarnding the best settings, when a map is going to be presented to people in cultures that read from left to right and top to bottom the 315 azimuth that manifold uses as staring value is the best. See Eduard Imhof's work on the subject. I haven't in mind what works best for people in east asia and I would like to know. Also I would like to know what works best in overall. I mean what azimuth settings would be a good compromise that would give the right impression to people all over the world.

lionel

455 post(s)
#20-May-18 14:21

Hi

1) where are the best ressource links from Eduard Imhof ?

2) does this post is relative to tanaka contour ?

hope manifold9 ll support some rendering find at www.shadedrelief.com

regard's

1) MacDEM;

2) Adobe Photoshop;

3) Natural Scene Designer;

4) MicroDEM;

5) MapRender 3D.


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geozap73 post(s)
#20-May-18 19:43

A book named Cartographic Relief Representation by Imhof is a must-read on the subject.

dale

533 post(s)
#24-May-18 13:29

I'm interested in more recent approaches to shaded reliefs than Imhof. Lionel's pointer to the rather excellent shaded relief website is a good start.

The exisiting 9 dialog box gives us no better functionality of just about any other GIS package. My challenge is to render pseudo realistic sea floors, where delicate features must be observable, without vastly exagerating large changes in depths.

My approach has been to prepare bathy raster data in MFD8, using it to extract and export resampled and smoothed black/white shaded relief, and the original DEM. I then create a Terrain Texture Shade (Leyland Brown) use a combination of Photoshop, or more recently, QGIS layer blending tools to blend the black/white relief and the hypso tinted terrain texture shade to produce a more subtle relief with detail intact.

Attached is a sample of such bathymetry. The bight in the top centre of the image has rippled scour depressions (RSDs) They are charactarised by change in depth of around 0.5m To the south of that bight are a pair of 100m deep scour holes, with exposed limestone walls. The presence of the RSDs and the holes are of equal cartographic importance. A simple shaded relief, like that generated by 8 and 9 will not produce such output.

So what would I like to see in nine?

Slider control on z value exageration, slider control on azimuth, slider control on height, with real time preview.

Implement Leland Brown's Terrain Texture Shader algorithm (a dialog box with a weighting slider that ranges from relief to texture shading)

Layer blending tools (like QGIS, PS, or other image editing tools)

Localised directional shading would be pretty nice, but layer blending can do that in a work around.

Attachments:
Texture shade.jpg

lionel

455 post(s)
#20-May-18 14:41

difference beetween shade and shadow

renderman ( pixar rendering engine ) support 3D light shad..

add shadow using renderman

ANT Landscape Add-on for blender

Attachments:
shade_shadow.png


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lionel

455 post(s)
#20-May-18 15:01

serifaffinity shadow


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lionel

455 post(s)
#20-May-18 15:21

Renderman for Blender Episode 1 - Displacement Tutorial!

wikipedia Displacement_mapping


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StanNWT65 post(s)
#24-May-18 16:08

Hi there,

The functionality you describe is and had been part of ER Mapper since the late 1990s. It shows for real time du shading changes. In 3D mouse you can also cuteness the vertical exaggeration real time like a rubber band on all surfaces. The caveat is that it's not the full resolution of the data and is a sub sample of the full 3D surface or surfaces based on how much RAM you want to use.

I suppose I could provide a screen grab of the hill shading tool. Basically it's two circles with a dot in the middle with a N/S/E/W cross hairs in the middle of the circle. The outer circle is the horizon, the inner circle which has half the radius of the outer circle is 45 degrees of inclination, and the dot in the middle is 90 degrees inclination. You just drag a point with out mouse around this circular space and the sun shading instantly changes. When I first saw this in 2007, when I got my first licence of ER Mapper with another organization I was blown away by how simple it was. However, I saw the demo of this back in 2001, when a sales rep came to my former organization doing a demonstration of the software. It was impressive that you could feather blend mosaic and colour balance 100 GB of air photo data that was contained on a CD-ROM, yes all on a CD-ROM, in 4 minutes with a Pentium 200 laptop with 64 MB of RAM and a 4200 RPM (at best) hard drive. The ER Mapper algorithm (.alg) approach is still impressive even though it's a mature product with no further development that I know of.

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