Measure Slope

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Arthurdiver
Posts: 3
Joined: Tue Feb 20, 2018 1:34 pm

Measure Slope

Post by Arthurdiver »

Hello

I'm a student in Oceanography, I work on complexity of substrate in marine bottom. For this use I generate 3D model with photogrammétrics technic.
And I measure my data on this model with cloud compare.

One of the data that I want to measure is the slope of the model. Models are rectangular and I want the slope on several section of the width.
Does someone know How it is possible ?

thank you
And sorry for my bad English
Arthurdiver
Posts: 3
Joined: Tue Feb 20, 2018 1:34 pm

Re: Measure Slope

Post by Arthurdiver »

Basiquely, I want to know the mean slope between this two point of my models
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point and slope
point and slope
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daniel
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Re: Measure Slope

Post by daniel »

In CloudCompare, there's basically two ways of computing the 'slope' (as the 'dip' and 'dip direction' values):
- either you fit a plane on a subset of points (at least 3, but in your case you can try to fit a plane on your whole cloud). You'll get the corresponding plane normal and also the equivalent dip and dip directions (either in the Console or in the plane properties dialog).
- otherwise if you have normal vectors expressed for each point of your cloud, you can convert them to 'dip and dip direction' values (Edit > Normals > Convert to > Dip / dip direction SF). If you don't have the normals, you can compute them with 'Edit > Normals > Compute' (see http://www.cloudcompare.org/doc/wiki/in ... %5CCompute). But to get the slope between your two extreme points, you would have to use a huge radius, and it would be a bit overkill. I think the plane fitting option should work better.
Daniel, CloudCompare admin
Arthurdiver
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Joined: Tue Feb 20, 2018 1:34 pm

Re: Measure Slope

Post by Arthurdiver »

Thank you daniel

The plane fitting option is easier and it work perfectly...
But I'm just asking how it work.
Witch point i use for determinate the slope orientation ( dip direction)
daniel
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Re: Measure Slope

Post by daniel »

Well, the plane fitting option uses all the points. You can segment the cloud (with the scissors tool) if you want to be more selective.
Daniel, CloudCompare admin
Ang08
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Re: Measure Slope

Post by Ang08 »

I have a doubt. Bow to measure angle of slope in CC? Like I can measure dip/dip dorection, but I need this for determining scanline or planar of slope, to use in dips (orientate the traverses). So if there any ideas, please share with me.
daniel
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Re: Measure Slope

Post by daniel »

Not sure, but you may be able to play with planes (primitives)? You can ether match planes on subsets of points, or create planes manually. Then you can select 2 planes and use 'Edit > Plane > Compare'. Among other things, you'll see the angle between the 2 planes...
Daniel, CloudCompare admin
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