Getting custom colormap onto 3D NVIZ in QGIS GRASS

Question

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.

The GIS SE Q&A at Changing raster color range in GRASS NVIZ did not really explain how to do it through the NVIZ module.

Answer 1

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":

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

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

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

• Two alternatives are available in the resulting dialog

• choose a color ("New constant")

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

With QGIS and the Processing/GRASS NVIZ

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

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