Best practices for changing facet color in custom mesh?

[zhutq]

Hi,

I've successfully created a custom mesh:

var vertexData = new BABYLON.VertexData();
// ... fill vertexData ...
var customMesh = new BABYLON.Mesh("custom", scene);
vertexData.applyToMesh(customMesh);

I want to change the color of some triangles in customMesh after it is created.

Which triangles to change is not known until run-time.

 What is the best practices to achieve this? Can I update only the affected part of the mesh data (like using glBufferSubData/glTexSubImage in GL)? 

Thank you very much!

[GameMonetize]

Hello

I suggest using vertex colors: http://www.babylonjs-playground.com/#2KEX2Y

 

[zhutq]

On 1/7/2017 at 0:50 AM, Deltakosh said:

Hello

I suggest using vertex colors: http://www.babylonjs-playground.com/#2KEX2Y

 

Thank you.

If I use vertex colors, like

sphere.setVerticesData(BABYLON.VertexBuffer.ColorKind, colors);

and I have set all vertex colors to red;

and then I want to change the color of only one vertex to green, 

do I still need to create the whole colors array again?

Is there any way to update only the single vertex to change? (Like using glBufferSubData instead of glBufferData in GL.)

[jerome]

You don't need to create the color array again as it is passed as a reference.

You just need to change, in this same array, the values of the wanted elements and then call again the updateVerticesData with this same array.

color4Array[66] = 1.0;   // will give the 66/3 = 33 th vertex of the "indices" array
color4Array[67] = 1.0;   // color = (1, 1, 1, 1)
color4Array[68] = 1.0;
color4Array[69] = 1.0;
mesh.updateVerticesData(BABYLON.VertexBuffer.ColorKind, color4Array, false, false);