Extrude a line from an already extruded shape vertices

Questions
1

Ok as I said in another post I’m a beginner on Babylon so I’m still getting the ropes of the framework. So I was trying to extrude a line from a known vertices location but not from an existing shape, so is there a way to take a vertex from an extruded polygon and then extrude just a line to a another known position?

So here is my shape in question:

image
image1329×628 75.1 KB

This is a rough idea of what I want but for every top vertex, the thing is that they are created by the for loop and I’m trying to do it by individual lines rather than from a known polygon.

What would be the best way to achieve my goal?

https://playground.babylonjs.com/#I56B00#14 here is playground link (with also the line things that I made down there), to make your life easier the for loops to make the tower starts from line 55.

Again Thanks for any help I get from this.

Edit: searching for a bit I discover the function “createLine”, everything good but the thing is that I still don’t know if I can use it directly from a known vertex in a created shape from a for loop.

2

If you have the paths then why not just transform the values by in the the extrude amount?

3

yeah, I did that or at least I think I did that, but babylon is not taking the vertex I want. Sure I can extrude to the amount I want but the thing is to take the vertex I want, like the ones from the top of every shape you see there in the playground.

For example I just did the thing with the lines, and they are relatively “well” but not even on a vertex, see my new playground to understand what I mean https://playground.babylonjs.com/#I56B00#15, so my goal is to connect every shape with one correspondent vertex.

4

Then you are not transforming the path correctly, the points should be fairly easy to get to.

torre[0].forEach(p=>{
p.addInPlace(BABYLON.Vector3.Up())
})

just from scanning your code this should work to get you the top points of your first box for example.

1 Like
5

That what I wanted to see! with this now I can have an idea of how to get the vertices I need! thanks!

6

Ok so… I got it work… kinda, the vertices are actually selected but it takes the origin polygon only, so I want the top or better said the last polygon from the iteration to work not the last one. https://playground.babylonjs.com/#I56B00#16 in my playground the for each actually just take the base vertices, not the last iteration vertices.

So I was thinking if it is possible to use the variable “piso” for something? like use a for each to get the vertices from the last iteration of “piso”?

7

I wish I understood Italian! I’m just using pattern recognition on your variable names and did not dive in to hard. I’ll take another look here when I get home for you.

1 Like
8

Is not italian, is spanish :stuck_out_tongue: in any way thanks for the help! I will be eager to hear more from you.

If you want the translation, Piso = floor, torre = tower, plano = plane, and I think the rest is self explanatory.

So I’ve been looking more, I found the VertexBuffer that I thought it gonna be my salvation but instead it gave me the entire list of coordinates, I managed to separate every floor in one variable with “window[“piso”+i+j]” but now I just need to take the last floor of every tower and take their vertex data so that I could use it as a position of the vertex.

https://playground.babylonjs.com/#I56B00#17 this has been my progress so far btw.

9

https://playground.babylonjs.com/#I56B00#18

1 Like
10

Omg, finally!!! this is what I wanted in the entire day!! I can’t thank you enough :smiley:

now I can extrude those lines with the algorithm.

one thing tho, can you tell me or give me the part of the documentation where it says about the function “point”? I want to study how it works, I’m gonna need it because now I need to select the points of the respective faces

11

That’s just the vector element in the array.

A vector can denote a position or a direction, in this instance we wanted a position, so with my parameters naming convention I just call that a “point”.

You could call it whatever.

1 Like