Question

Opposite from an Extruder?

  • 7 February 2017
  • 6 replies
  • 0 views

Badge +6

I have this problem.

 

I Have surfaces (triangles) which looks like an extruded surface. (with a ground layer and a layer above)

 

like feature looks like coming out from an Extruder transformer.

 

 

Which transformer i use to get only the "roof" layer (the highest layer or thickness)...so in my opinion to delete all triangles which goes from roof to ground level.

I dont know if i use the right english words to explain my problem.

Greetz

Franco


6 replies

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Hi @franco69

 

 

It is hard to really visualise your problem. Could you maybe add a printscreen from the 'extruded' feature?

 

Badge +6

i have no data yet....but my colleague will send me one...but i have an example picture from the WEB....

 

i have geological layers (different colors on the picture) as a mesh (horizontal and vertical triangles)...for a xample blue layer......and i only want the horizontal highest triangle (or surface) and clip all triangles to the floor and the floor itself.

 

Badge +16

Hola @franco69,

Just guessing here....but to visualize the layers differently an attribute value is probably used, any chance you can use that to separate the layers?

Badge +6

i have already separate the layers....so when i take this example i have a blue mesh, a green one, etc.....

 

but i dont want the whole blue mesh...for example...only the highest surface...not the ground
Userlevel 2
Badge +17

Hi @franco69, theoretically the normal vector z-component of vertical faces should be equal to 0, so my idea is:

  1. Decompose the surface into individual 3D triangles.
  2. Calculate normal vector of them.
  3. Filter out triangles whose normal vector z-component is nearly equal to 0.
  4. Reconstruct surface from the remaining triangles.

Note: I think that the processing could be very slow if the number of triangles in the source surface is so large. And transformers that can be used to perform this processing may be different depending on the actual geometry structure of the source surface.

Badge +16

i have already separate the layers....so when i take this example i have a blue mesh, a green one, etc.....

 

but i dont want the whole blue mesh...for example...only the highest surface...not the ground
Would be easier if you can share the data, will wait for that.

 

 

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