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I am trying to create a 3D version of my 2D raster using QGIS GRASS NVIZ. I have been following these steps: http://linfiniti.com/2010/12/3d-visualisation-and-dem-creation-in-qgis-with-the-grass-plugin/

I have no problems creating the 3D model, but my colors always get lost. This is frustrating because the second option on the NVIZ module asks for a raster to use for color. I've tried multiple times to get NVIZ to create the 3D model with the color of the raster indicated and I always get the Pseudocolor or grayscale colormap. The link provided in the above directions (http://linfiniti.com/2010/12/a-workflow-for-creating-beautiful-relief-shaded-dems-using-gdal/) claims to explain how to map colors, but does so only through command line procedures. I am not yet familiar enough with GRASS command line to take that route and meet my deadline.

This GISSE question did not really explain how to do it through the NVIZ module: How to change the raster color range in GRASS NVIZ?

Any suggestions would be much appreciated.

-mike

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This is not QGIS, but GRASS GIS so you need to know GRASS GIS to use NVIZ.

With GRASS GIS or QGIS and the GRASS plugin

Each raster can have a color table and r.colors creates and/or modify this color table, here for a DEM with color table "elevation":

enter image description here

  • when you use NVIZ, this color table is used by default ("elevation" here) :

enter image description here

In other words, you have to replace the raster color table with r.colors if you want to change the default -> "rainbow" here ):

enter image description here

  • but you can also change this color table in NVIZ with "color:..." (and you can see that the default color = raster table color):

enter image description here

  • Two alternatives are available in the resulting dialog

enter image description here

  • choose a color ("New constant")

enter image description here

  • choose another layer ("New Map"), allowing to drape a 2D map (geological here) onto a DEM, for example:

enter image description here

With QGIS and the Processing/GRASS NVIZ

Here only the current layer is available due to the algorithm used

enter image description here

So you can only modify the color ("New constant")

enter image description here

  • Thanks for your reply. Could you clarify a couple of things please? I am using the GRASS tools in QGIS and my windows do not fully match the ones you displayed in your answer. Is the custom colorizing of 3D rasters achievable through the GRASS tools in QGIS? And why is there an option to set the raster color in the NZIV module in QGIS if it doesn't set the raster color? – mikeLdub Nov 2 '13 at 14:38
  • do you use the GRASS Plugin or the GRASS command in Processing ? (see my adapted answer) – gene Nov 2 '13 at 19:21
  • GRASS Plugin with QGIS 1.8 – mikeLdub Nov 2 '13 at 21:01

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