[R] rgl zooming to an arbitrary location

[Gareth Davies]

Fantastic -- the pan3d function in the example for rgl.setMouseCallbacks 
solves the problem.

For illustration:

##################

library(rgl)

# Get the pan3d function by running this rgl example [ignore the error 
caused by not having an open rgl device]
example(rgl.setMouseCallbacks)

#Make up some topography
x=runif(1e+06, min=0,max=1000)
y=runif(1e+06, min=0,max=1000)

# Elevation with 'hill' in the centre
z=sin(x/50.)+cos(y/50.) + 30*exp(-((x-500)^2+(y-500)^2)*0.001)

plot3d(x,y,z,col=z+3,aspect=FALSE)
pan3d(3) # This makes my 'middle' mouse button function like pan



On 02/09/14 06:25, Duncan Murdoch wrote:
> On 31/08/2014, 11:12 PM, Gareth Davies wrote:
>> I have been using rgl to view xyz point clouds containing topographic
>> data ( with around 10^5 - 10^6 points).
>>
>> It's working well aside from one thing: I would like to be able to zoom
>> into an arbitrary part of the plot. However so far I could only figure
>> out how to zoom into the centre.
>>
>> See the example below -- in this case, I cannot 'zoom-in' to anything
>> other than the central hill in the topography, whereas I would like to
>> be able to zoom to an arbitrary location.
>>
>> Is there a way to get around this?
> Yes, you can manually set the userMatrix transformation.  See ?par3d for
> a discussion about how rgl figures out what to display.  See the example
> in ?rgl.setMouseCallbacks for some code that does something like what
> you want.
>
> There are plans to make this a little simpler in the next major release,
> but no definite release date.
>
> Duncan Murdoch
>
>> ##########################################
>> # EXAMPLE CODE
>> ##########################################
>> library(rgl)
>> # Make up some topography
>> x=runif(1e+06, min=0,max=1000)
>> y=runif(1e+06, min=0,max=1000)
>> # Elevation with 'hill' in the centre
>> z=sin(x/50.)+cos(y/50.) + 30*exp(-((x-500)^2+(y-500)^2)*0.001)
>> plot3d(x,y,z,col=z+3,aspect=FALSE)
>> # Now try zooming [right mouse button]. I can only zoom into the central
>> hill, not elsewhere.
>>
>>
>> Below are the details of my R Install
>>
>>   > sessionInfo()
>> R version 3.1.1 (2014-07-10)
>> Platform: x86_64-unknown-linux-gnu (64-bit)
>>
>> locale:
>>    [1] LC_CTYPE=en_AU.UTF-8       LC_NUMERIC=C
>>    [3] LC_TIME=en_AU.UTF-8        LC_COLLATE=en_AU.UTF-8
>>    [5] LC_MONETARY=en_AU.UTF-8    LC_MESSAGES=en_AU.UTF-8
>>    [7] LC_PAPER=en_AU.UTF-8       LC_NAME=C
>>    [9] LC_ADDRESS=C               LC_TELEPHONE=C
>> [11] LC_MEASUREMENT=en_AU.UTF-8 LC_IDENTIFICATION=C
>>
>> attached base packages:
>> [1] stats     graphics  grDevices utils     datasets  methods base
>>
>> other attached packages:
>>    [1] rgl_0.93.1098        unstructInterp_0.0-1 rgeos_0.3-6
>>    [4] rgdal_0.8-16         sp_1.0-15            geometry_0.3-4
>>    [7] magic_1.5-6          abind_1.4-0          SearchTrees_0.5.2
>> [10] roxygen2_4.0.1
>>
>> loaded via a namespace (and not attached):
>> [1] digest_0.6.4    grid_3.1.1      lattice_0.20-29 Rcpp_0.11.2
>> [5] stringr_0.6.2   tools_3.1.1
>>   >
>>
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>>