Managing multiple DEMS with corresponding geog image shaders

Started by ssalvador, July 03, 2015, 11:31:03 AM

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I've loaded DEMS of various resolutions into my model and all is well until I load their corresponding geog image shaders.  The heightfields are hierarchically combined according to their placement order in the terrain node list, howeve,r when I load the surface shaders with georeferenced images corresponding to each DEM, the last one loaded wipes out the previous one. 

I haven't been able to figure out how to fix this and any help would be appreciated.



Can you perhaps show some example renders of the problem? Am I understanding correctly that you are trying to use Geog Image Shaders at *different spatial resolutions* (i.e. one larger, lower per-meter resolution image to cover a big area, then smaller, higher per-meter resolution ones to cover area of interest)? In other words you're trying to overlap the orthoimagery the same way you're overlapping DEMs, to get realistic texture coverage to the horizon without using too much memory?

- Oshyan


Hi Oshyan,

I've attached figures showing the terrain nodes, shader nodes, and 2 renderings.  The hires_visible.jpg shows the higher resolution aerial image covering the extents of the hires terrain.  The lores_visible.jpg shows the lower resolution aerial image covering the extents of the lower resolution DEM.  When all geog images are enabled you get the image in hires_visible.  When I disable the hires geog image, you get the image in lores_visible.   

Your assumptions are correct in what I am trying to do.



Guessing from the node screenshot, it is probably the Surface Layer that causes the white surface. On the surface layer, uncheck "Apply colour". Then connect the Geog Image Map Shader as the child layer for the surface layer.

You may not even need to use a Surface Layer at all, if all you want to do is apply the texture.

Just because milk is white doesn't mean that clouds are made of milk.


Hi Matt,

Your suggestions fixed my problem.   

Thank you.