9 replies to this topic

[Hans van der Maarel]

This is for a little hobby project that I hopefully have some more time for in the next few weeks.

I want to do a shaded relief map with some overlays. I've been toying a bit with the software (VNS, Photoshop) and adding some manual touches. I set up 2 renders in VNS: an elevation-driven color (going from green to reddish brown) and a second one that renders black on slopes that face away from NW. I could add both textures into one in VNS and save half of my render time, but this way I can keep them in separate Photoshop layers.

 org.jpg   155.99K   232 downloads

Exhibit one. Both layers in Photoshop. Notice the noisy look of the whole, due to the sourcedata (SRTM).

 blur.jpg   71.96K   197 downloads

Exhibit two. Blurred both layers (Gaussian Blur) to the point where you *just* can't see the pixellation anymore.

 with_manual.jpg   79.8K   255 downloads

And finally number three. I took out my Wacom and added some extra touches, using the original shading layer as a guide. You can see I have been experimenting with various brush sizes and settings (and this is not meant as a final product yet) to try and find the best mix.

So what do you guys think? Am I on the right track? The result shown in #2 is easy to accomplish, adding the manual stuff is obviously going to take time.

[DaveB]

The colors are a bit strong for my tastes, but they may suit your needs and can always be toned down as needed.

As for the manual shading have you looked at Tom Patterson's work? He has a site called Shaded Relief and has done a LOT of research into this subject. He's also a great guy to talk to if you get a chance to meet him in person (and usually does at least one session at NACIS, plus a Practical Cartography Day session, among other things).

[franciscocartographer]

Very nice work. I like the manual generalization. I can definitely see the improvement from the original SRTM.

Have you read the article “Hillshading of Terrain Using Layer Tints with Aspect-Variant Luminosity"? Link

I am planning in practicing hillshade manual enhancing myself. Doing a lot of Imhof reading these days…

[Mike H]

hans - what is the final map going to be about? Reason I ask is you may want to fade the colors back a bit if you are adding vector and text layers. I've found it's best to stop the relief design part at an early stage - throw the other data and text and essential crap on it, then have a look and see what design challenges the overall mess is presenting.

m.


hmmm, "crap" and "mess"... you can see where my head is today - sorting through a lot of data layers this morning ... add a pinch of tiger data, a cup of place names, 2 cups of hydro, a pinch of political boundaries... pour on top of half-cooked relief model... let simmer. Must...have..more..coffee...!

[Matthew Hampton]

This looks like you are on the right track. You might get better results by using the elevation data in Photoshop and creating the DEM/tint using the lighting effects a la Patterson. Using the methodology he spells out (link below) you can also upsample the elev data to remove the pixely stuff before creating the shading.

I know the manual work takes forever - but you have it looking a lot better than the auto-method.

[Hans van der Maarel]

Thanks for the comments. I'm currently re-rendering the basic elevation layer with more subtle colors. I'm aware of the tutorials Tom Patterson did and I definately want to incorporate some of that in this project.

I'm not even sure what this map is going to be about. I took my GPS receiver on a road trip from San Jose to Monterey and was thinking of doing some visualisation stuff with this data. Mainly to keep doing some map design work rather than the GIS data manipulation that occupies most of my working hours at the moment. I just want to work with some different datasets and try out different things.

[Rob]

Hans,

those touch ups do add some nice depth. I've used the gausian blur too, but always feel the output looks unnaturally blurry. For generalization I'd be incline to apply the blur filter to the DEM before rendering, not after.

Lately i've been doing a lot of my VNS hillshade rendering with a very light gray gournd component. That's it. This will give me a grayscaled image I can tweak in PS and use as a filter in an adjustment layer to drive the shading. Much like Pattersons method but I prefer using a color adjustment, filling it with a dark gray, and then controlling the final shade with opacity. This has helped me keep the shading independent from the other terrain coloring and patterns, so they can be edited without messing the hillshade. Some manual touch ups to the filter also help to smooth things out and place desired highlights.

rob

[Hans van der Maarel]

Rob,

I agree on the Gaussian Blur. It does help to get rid of a lot of the noise that's in the render, but it makes it look too blurry (and it makes my eyes go funny... it seems to trigger them to try and focus).

I want to try and use a Sharpen filter after the Gaussian Blur, see if that can bring the crispness back. But maybe an area terrafector prior to rendering can work just as well...

One thing I've noticed is that there's a lot more control over the final outcome if you combine these layers in Photoshop rather than have them together in a single texture in VNS. A little bit more or less opacity can really make a difference and in PS you just seem to have a more direct control over it.

[Rob]

Hans,

how would you go about using an area terraffector to do this? would be interested in your method if it's possible. I currently do this in leveller.

thx, rob

[Hans van der Maarel]

Rob,

I'm not sure yet I'll have to play with it a bit.