- #Particle designer webgl how to#
- #Particle designer webgl update#
- #Particle designer webgl code#
- #Particle designer webgl plus#
If this value is less than zero, then we pin the value to zero, since you can't have less than zero light. We can then compute the amount of directional lighting that needs to be applied to the vertex by calculating the dot product of the transformed normal and the directional vector (that is, the direction from which the light is coming). The first thing we do is transform the normal based on the current orientation of the cube, by multiplying the vertex's normal by the normal matrix.
Once the position of the vertex is computed, and we pass the coordinates of the texel corresponding to the vertex to the fragment shader, we can work on computing the shading for the vertex. VLighting = ambientLight + (directionalLightColor * directional) Highp float directional = max(dot(transformedNormal.xyz, directionalVector), 0.0) Highp vec4 transformedNormal = uNormalMatrix * vec4(aVertexNormal, 1.0) Highp vec3 directionalVector = normalize(vec3(0.85, 0.8, 0.75)) Highp vec3 directionalLightColor = vec3(1, 1, 1) Gl_Position = uProjectionMatrix * uModelViewMatrix * aVertexPosition
#Particle designer webgl code#
Then we add the code to drawScene() to bind the normals array to a shader attribute so the shader code can get access to it: This should look pretty familiar by now we create a new buffer, bind it to be the buffer we're working with, then send along our array of vertex normals into the buffer by calling bufferData(). ARRAY_BUFFER, new Float32Array (vertexNormals ) , ARRAY_BUFFER, normalBuffer ) const vertexNormals = Building the normals for the verticesĬonst normalBuffer = gl.
#Particle designer webgl how to#
We'll see how to do that when we look at the code for the shader.
#Particle designer webgl update#
Then we update the vertex shader to adjust the color of each vertex, taking into account the ambient lighting as well as the effect of the directional lighting given the angle at which it's striking the face. We need to know the direction in which the light is traveling this is defined by the direction vector.
This is a vector that's perpendicular to the face at that vertex. We need to associate a surface normal with each vertex.Once you drop out the concept of point sources and specular lighting, there are two pieces of information we'll need in order to implement our directional lighting:
#Particle designer webgl plus#
Instead, we'll have our ambient lighting plus a single directional light source, aimed at the rotating cube from the previous demo. A light bulb emits light in all directions, for example.įor our purposes, we're going to simplify the lighting model by only considering simple directional and ambient lighting we won't have any specular highlights or point light sources in this scene. This is how many real-world light sources usually work. Point light is light that is being emitted from a point, radiating in all directions. Sunlight, for example, is considered directional light. This is light that's coming from so far away that every photon is moving parallel to every other photon. Instead of discussing it in depth here, take a look at the article on Phong shading at Wikipedia, which provides a good overview of the most commonly used lighting model or if you'd like to see a WebGL based explanation see this artcle.Īmbient light is the light that permeates the scene it's non-directional and affects every face in the scene equally, regardless of which direction it's facing.ĭirectional light is light that is emitted from a specific direction. Although going into detail about the theory behind simulated lighting in 3D graphics is far beyond the scope of this article, it's helpful to know a bit about how it works.