3d PieSlice from code

hhoria · September 1, 2021, 12:12pm

Hi everyone,
I’m trying to generate a PieSlice, similar on how 3ds max is doing for tube or cylinder with the slice option( slice from x1 degrees to x2 degrees)
Any idea where i should start looking into?

eproasim · September 1, 2021, 12:14pm

Hi @hhoria,

Is this for a 2D UI element use-case?

hhoria · September 1, 2021, 12:16pm

Hi, it would be 3d, I need it to visually show the measurement of angles between 2 surfaces

mvaligursky · September 1, 2021, 1:38pm

any screenshot of what you’re after?
It sounds like you could draw lines?

hhoria · September 1, 2021, 1:46pm

This is a slice from 0 to 90 degrees

Something similar, it can be purely flat, but I’d need it in 3d world space

hhoria · September 1, 2021, 1:56pm

It doesn’t necessarily need to be solid fill, it can be just the contour as well

mvaligursky · September 1, 2021, 1:59pm

You’d use mesh API and generate triangles as needed
https://developer.playcanvas.com/en/api/pc.Mesh.html

something along these lines (this generates 2D plane and later deforms it)
http://playcanvas.github.io/#/graphics/mesh-generation

similar example on how the engine generates cylinder primitive:

github.com

playcanvas/engine/blob/6d9b030335d517e18046bdb564e960a01c7b17cb/src/scene/procedural.js#L607

    
      
          * is generated into the vertex buffer of the cylinder's mesh.
          * @param {GraphicsDevice} device - The graphics device used to manage the mesh.
          * @param {object} [opts] - An object that specifies optional inputs for the function as follows:
          * @param {number} [opts.radius] - The radius of the tube forming the body of the cylinder (defaults to 0.5).
          * @param {number} [opts.height] - The length of the body of the cylinder (defaults to 1.0).
          * @param {number} [opts.heightSegments] - The number of divisions along the length of the cylinder (defaults to 5).
          * @param {number} [opts.capSegments] - The number of divisions around the tubular body of the cylinder (defaults to 20).
          * @param {boolean} [opts.calculateTangents] - Generate tangent information (defaults to false).
          * @returns {Mesh} A new cylinder-shaped mesh.
          */
          function createCylinder(device, opts) {
             // #if _DEBUG
             if (opts && opts.hasOwnProperty('baseRadius') && !opts.hasOwnProperty('radius')) {
                 console.warn('DEPRECATED: "baseRadius" in arguments, use "radius" instead');
             }
             // #endif
          
          
   // Check the supplied options and provide defaults for unspecified ones
             var radius = opts && (opts.radius || opts.baseRadius);
             radius = radius !== undefined ? radius : 0.5;
             var height = opts && opts.height !== undefined ? opts.height : 1.0;