Viewshed Analyses in Povray– Final Image

I completed this project a long time ago and have not blogged on it in over a year.  None-the-less, I realized that I hadn’t posted any final images for the viewshed analysis with Povray. So here is the summer viewshed analysis.  This is rendered with about (I think) 150,000 trees, each with 100,000+ leaves.  The cell tower here is in red.  The landscape colored in … Continue reading Viewshed Analyses in Povray– Final Image

Digital Surface Model– a whole forest and more part Deux

Just another shot of our digital surface model of the forest.  This time, I rendered it with all of the trees at base elevation 0 (zero), placed the orthographic camera at height 150, so our 16-bit range we’re rendering to should scale 0-150 feet to 0-65535 values, giving us a precision of 0.002 feet.  The original LiDAR data has a precision of 0.01 feet, so … Continue reading Digital Surface Model– a whole forest and more part Deux

Digital Surface Model– a whole forest and then some

Let’s start putting some of the pieces together.  Earlier, I presented a method for deriving a digital surface model from LiDAR data of a forest canopy, using a tree-shaped interpolator that scales the individual tree canopy shapes according to the height of the LiDAR return from the ground.  Now I present the whole project, forest and all.   I wanted to render my DSM at a … Continue reading Digital Surface Model– a whole forest and then some

Modeling (relative) Sub-Canopy Biophysical Variables with PovRay

One of my goals in modeling canopy height is to estimate sub-canopy biophysical variables that give indications of habitat suitability.  For example, suppose we have a rare plant that is canopy gap dependent.  How do we model it’s distribution?  With a statewide LiDAR dataset from which we can derive canopy location and height, we can identify canopy gaps.  While I haven’t gotten to the modeling … Continue reading Modeling (relative) Sub-Canopy Biophysical Variables with PovRay

Optimizing Pov-Ray include files– smaller trees with the same effect

One limitation I’ve run into in rendering large scenes of trees in PovRay, whether for fun for work is memory usage.  I’ve found that about a half million trees is about as many as I can place on a 32-bit system before running out of memory.  Sometime this year I’ll switch to 64-bits, but in the mean time, I hacked together a solution for reducing … Continue reading Optimizing Pov-Ray include files– smaller trees with the same effect

Rendering a vegetation surface model using PovRay (cont.)

Below is my metacode for iterating through a grid of images to render the vegetation surface model from povray.  The real code will be implemented in BASH and AWK, although this would be a perfect use of Python, if I knew how to use it… . PostGIS Tables: cuy_veg_points:        Load veg points into database and make 2D geometry cuy_terrain_points:        Load terrain points into … Continue reading Rendering a vegetation surface model using PovRay (cont.)

Rendering a vegetation surface model using PovRay

Early on, I was working on the problem of rendering a virtual forest based on real LiDAR data in order to do things like a detailed, vegetation included, viewshed.  There are other things we can do with this data, including discovering the boundary of the canopy (and thus find canopy gaps) and rendering a vegetation surface model. Let’s start with a single tree.  If we … Continue reading Rendering a vegetation surface model using PovRay

No Image– a very simple solution for calculating viewshed

Not much to say here. I had a bit of inspiration, remembering a Christoph Hormann tutorial http://www.imagico.de/pov/icons.html on making transparent icons in povray and realized that what he was describing was the final piece in the povray for viewsheds milleau: no_image option for an object forces it to interact with the scene in every way, but to be seen by the camera. I’ll post the … Continue reading No Image– a very simple solution for calculating viewshed

POV-ray for GIS Visualization

This is a “wouldn’t it be nice” post– i.e. a I-don’t-have-time-to-write-it-and-everything-else-on-my-list post. Wouldn’t it be nice if in addition to returning GeoRSS, WFS, OGC, KML, etc. GeoServer returned a POV-Ray file? It could be returned as part of a simple GET post like this: http://localhost:8080/geoserver/wms?bbox=2100506,575982,2290532,739026&styles=&Format=application/povray&request=GetMap&version=1.1.1&layers=base:contours&width=800&height=644&srs=EPSG:102722&camera=2195519,657504,1000&look_at=2195029,657004,500 Vector symbolization could be a POV-Ray approximation of the WFS render styles using coordinates and POV primitives. Also, a PHP … Continue reading POV-ray for GIS Visualization

Povray Viewshed with Trees (finally) (cont.)

Ok, your average terrain-only based viewshed (view is from a road to the southeast, viewshed is in cyan): Note that based on these estimates, we should be able to see most of the valley walls from this little slice of road.  I don’t buy that.  That section of road is pretty closed in with trees.  Let’s add them: As you may see, just a little … Continue reading Povray Viewshed with Trees (finally) (cont.)