fooman wrote:Hi Michael,
Another quick play, to get volumetric data. Method as below:
Slice of redwood creek giant, 0<z<20ft.
Imported spreadsheet data containing vertex data with 0<z<20ft as .ply into Radidform. Automatically mesh. Filtering of extranous data points, 80% sampling ratio. Automatically filling holes resulted in smoothed, interpolated surfaces at z<0ft and z>20ft. Trimmed resultant mesh back to 0<z<20ft. Global remeshing resulted in slight smoothing of edges. Volume calculated at ~3076 ft3, with face normals pointing inwards (calculation instantaneous). Corrected normals to obtain "correct" model display, but unable to obtain a volume calculation. Mesh shown below:
Ran free form volume solver-RGC.xls with the following settings:
Range Filters # of Points = 61627 127 = # of Slice Points
Xmin -10.000 Xmax 11.000
Ymin -10.000 Ymax 11.000
Zmin -1.000 Zmax 30.000
Pole XYZ 0.000 0.00 0.000
Zcookie 0.000 Thickness 0.200
Ht Start Pt 0.000 Ht End Pt 20.000 Int 20.000
Slice Thickness 1.000 Ray Incº 1.00
Took about 10 minutes to get the result:
Total Volume 3163.027
The mesh volume is ~ 97% of the numerical intergration volume. The difference is likely to be in the filtering/smoothing/filling undertaken on the mesh plus the residuals inherent in the numerical integration method (e.g. as a function of ray angle/slice sizes).
This seems to be a reasonably good result.
Did your RCG shape table originally have only 65k points ? That surface mesh looks fantastic with excellent curvature effects. The original scan I made of RCG has 197k points but I could only fit 65k on the spreadsheet.
Did you cut and paste the XYZ data from the RCG spreadsheet into a text file for Rapid Form ?
How long did the Mesh layer take to create ?
Did Rapid Form decimate the data after Meshing ?
Is your Mesh created from the orignal 65k XYZ points from my RCG volume spreadsheet ?
Does Rapid Form do a surface volume calculation ? I would assume yes.
I hope to get within 1% of RapidForm. I am not satisfied with 3%. It should be better. We'll see how the coding goes. I am fairly certain the error is on my end. Thanks again for your help,
Very interesting, your included presentation and paper. Good work from Down Under!
Regarding the paper, my curiosity is piqued...the correlation between wood quality with sweep and dbh was mentioned in the context of a tree growing into a canopy gap. Sweep in excess, diminishes wood quality from the perspective of the mill...presumably an inverse relationship? That is to say, the less sweep the better the correlation with wood quality?
Kind of works against:
"Sweep exhibits moderate positive correlations with crown area, volume and density. This would
imply that trees with more foliage are more prone to sweep. This agrees with the findings of
Suarez et al. (2010) who found that stem straightness was inversely proportional to stand spacing.
It is well known that canopy size and volume are proportional to stand spacing."
I follow the thought that increased canopy opening (increased stand spacing) allows more photosynthesis opportunity/photosynthate production as the tree fills the space. But there are two (hmmm, at least...: > ) dynamics here, and the tree growing out (increasing diameter), and the tree growing up (increasing height), both adding volume. These dynamics typically occur in the order listed, in a canopy opening scenario. But I'm not sure I follow the 'implication' that "trees with more foliage are more prone to sweep'...that logic if extended would also imply that the greater the sweep, the great the wood quality. Neither timber mills nor the paper industry would want compression wood/tension wood that accompanies excess sweep.
Well, perhaps I've belabored the point, and unfairly extended implications...a thought provoking paper nonetheless!
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