solved Create ramp for ground

[Dad72]

Hi,

I am looking to create a ramp system. But I do not succeed in making it. Is what anybody has of idea of how?

At the moment, I raise summits which form a mountain and I wish that by choosing vertexes from top of the mountain, then the vertexes of the bottom of the mountain, this will create a ramp.

I found a sample video that looks like what I would like to do:

How can this be done?

Thank you for your help

[V!nc3r]

Why not just model ramps in 3d modeler ?

[Dad72]

It is for a terrain editor that I do. So I need to have this tool for my editor. But I do not know yet how.

[Dad72]

I start a PG of what I have until the. 

There are two modes. One for the vertex elevation and another for the ramps. It changes to line: 43 and 44 (To be changed manually) By default elevation mode is actived

The function to make the ramp is line 171

Currently I select the vertex on functions: line 129 and 150 and I save them in an array. This corresponds to the beginning of the ramp towards the end. But I'm not sure if what I have started is correct. 

I wanted to take inspiration from the function: line 279 coming from worldmonger on the site of Babylon 

http://www.babylonjs-playground.com/#RKPBE#13

I hope there is some expert on terrain sculpture that will help me. This is the last thing of complicate with my editor.

Thank you for you help

[getzel]

Waho the terrain editor looks promising.

[Dad72]

Yes, There are other tools with:

I also intend to add different brushes too. But I still have the problem of ramps with which I really struggle. The other tools work.

[Gugis]

You have 2 variables - topPoint (at the top of the mountain) and bottomPoint (at the bottom of the mountain). Now you have to caculate distance and height difference between these two points:

var totalDistance = Math.sqrt((topPoint.x-bottomPoint.x) * (topPoint.x-bottomPoint.x) + (topPoint.z - bottomPoint.z) * (topPoint.z - bottomPoint.z));
var heightDifference = topPoint.z - bottomPoint.z;

Next you have to select which vertices you need to update, for that use https://en.wikipedia.org/wiki/Bresenham's_line_algorithm

Loop through all vertices and calculate how far from bottom point current vertex is (use first method):

var currentVertexDistance = Math.sqrt((bottomPoint.x-currentVertex.x) * (bottomPoint.x-currentVertex.x) + (bottomPoint.z - currentVertex.z) * (bottomPoint.z - currentVertex.z));

For getting proper height of current vertex you have to calculate distance ratio between current vertex and bottom point:

var heightRatio = currentVertexDistance/totalDistance;

Finally height of current vertex:

currentVertex.z = endPoint.z + heightRatio * heightDifference;

I am not sure that i wrote everything 100% correctly, but it should be something like that.

[Dad72]

Woaw, I do not understand for the use of Bresenham's_line_algorithm. In any case, thank you for this theoris and sample code.

[Gugis]

9 minutes ago, Dad72 said:

Woaw, I do not understand for the use of Bresenham's_line_algorithm. In any case, thank you for this theoris and sample code.

Here's javascript function of this algorithm: http://stackoverflow.com/questions/4672279/bresenham-algorithm-in-javascript/4672319#4672319

 

[Dad72]

Thank you. It's complicated, I have a headache.

Would you have time to help me reproduce this on this playground?

http://www.babylonjs-playground.com/#RKPBE#13

Thanking you in advance

 

[Gugis]

There's a lot of work to do. The most I can do is to guide you.

[V!nc3r]

And why not paint on a heightmap and update the terrain on live rather than directly "paint" mesh data ? Would it not be easier ?

[adam]

It would look cool.  I don't think it would be easier, though.

 

[Dad72]

I try but I can not and I think I did absolutely anything. 

I modify the PG in ways to create a small mountain and automatically switch to ramp creation mode (when you can create more mountain)

But what I did does not work for Ramp mode. I do not even understand what I do. 

http://www.babylonjs-playground.com/#RKPBE#16

[Dad72]

I try another approach that is also a total failure. 

I drop this feature that takes me too much head and I will finish no longer have hair on my head. I can not do it and I do not think I can do it tomorrow either.

You can always create ramps manually by gradually elevating the tops at the moment. So I'll settle for that. I do not have the level for that kind of "chemistry mathematics".

[gryff]

34 minutes ago, Dad72 said:

I drop this feature

@Dad72 I have known you on this forum for almost 3 years - not known you to give up easily.

C'est mauvais

cheers, gryff

[adam]

I'll give it an attempt over the weekend.

 

[Wingnut]

SO, now...  hehe... gray scale image... used as a heightMap or displaceMap... that has a "quantized" number of available steps, yes?

256 colors of gray?  So, ramps made from gray-scale... that use our displaceMap system... will get a "steppy" ramp... yes?

But a modeled ramp... or a math-derived map... would give a much smoother ramp, yes?

Ok, just checking. 

The granularity (subdivs) of the ground... will need consideration... (duh wingy).  hmm.

Can a ramp get wider or narrower... as it ascends/descends?  (Wingy digs in his bag for some aspirin).

[Dad72]

Thank you Gryff, Adam and Wingnut for your support. 

Yes, Gryff I'm not the type to give up generally easily, but I feel like I run into a big wall. I do not know at all how to do and rather than do anything/to make bullshit, down I prefer to stop. My ideas exceed my skills sometimes. 

But thanks. If you get there, Adam, I would try to understand what you did for learn. Thank you for giving a try to this headache and do not you care if you do not succeed.

[Gijs]

Hi, it's a fun challenge! I tried my best to make something like in the video, and here are the results:

This is the standalone version. You can adjust the brush size.

http://www.babylonjs-playground.com/#RKPBE#17

Tip: enable wireframe mode on the material to see the geometry better.

This is your #13 mixed with my #17:

http://www.babylonjs-playground.com/#RKPBE#18

I saw buttons in your demo very briefly, but for some reason they usually don't show. I made the middle mouse button for 'ramp' instead, left is to make mountains.

Hopefully it is of some use to you. Good luck with your project!

[Dad72]

Woaw, it's really cool. Thank you so much Gijs. 
I will study what you have done to learn.

Thanks again. 

[Dad72]

I studied the code you did. I'm impressed, I would never have done that. You made a quality system. This is really perfect.

Great thank you for helping me with this.

[Gijs]

30 minutes ago, Dad72 said:

I studied the code you did. I'm impressed, I would never have done that. You made a quality system. This is really perfect.

Great thank you for helping me with this.

You're welcome, but I just thought of a more general method of doing such things, so if that works out, the ramp code may soon be obsolete

[getzel]

There are some coding heros on this forum !

[Dad72]

4 hours ago, Gijs said:

but I just thought of a more general method of doing such things, so if that works out, the ramp code may soon be obsolete

If there is one manners more general, I definitely want to see it.