gl-shape

Create 3d shapes for use with stack.gl.

This module provides a constructor that wraps gl-geometry and gl-mat4, making it simpler to create a geometry from a simplicial complex and update its transforms.

install

npm install gl-shape

example

Define data for your shape

var data = {
  complex: require('bunny'),
  position: [0, 10, 20],
  scale: [1, 2, 1]
}

Then create it

var shape = require('gl-shape')(data)

You can bind its geometry to a shader

shape.attributes.geometry.bind(shader)

Use its matrices to set uniforms

shader.uniforms.model = shape.attributes.model

And update its position (which updates its underlying model matrix)

shape.position([0, 10, 0])

See example.js for a complete example of a rendered 3d shape, and call npm start to run it.

usage

shape = require('gl-shape')(gl, data)

Create a shape by providing a gl context and shape data.

The following properties on data are required

• complex the simplicial complex, must have positions and faces, may also have uvs and normals. If normals are not provided, vertex normals will be computed using normals.

And the following are optional

• position an 3 vector with a position
• scale an 3 vector with a scale in each dimension or a scalar
• rotation an object with rotation angle theta and 3 vector axis
• model a 4x4 matrix for directly specifying the model matrix
• flatten a boolean flag that if true will convert indexed meshes to triangles for non-interpolated geometries

If position, scale, or rotation are specified they will be used to set the model matrix.

shape.attributes

All derived attributes are stored on shape.attributes, and include

• geometry the renderable geometry
• model the 4x4 model matrix
• modelNormal the normal vector for the model

shape.position(vector)

Update the position.

shape.scale(vector)

Update the scale along each dimension. Can also pass a single value.

shape.rotation(angle, axis)

Update the rotation.