Addresses issue #6519

src/webgl/3d_primitives.js

@@ -180,6 +180,14 @@ p5.prototype.freeGeometry = function(geometry) {
   this._renderer._freeBuffers(geometry.gid);
 };
 
+/**
+ * Clears the internal Color of the Geometry.
+ * @method clearColors
+ */
+p5.prototype.clearColors = function () {
+  return this._renderer.clearColors();
+};
+
 /**
  * Draw a plane with given a width and height
  * @method plane

src/webgl/p5.Camera.js

@@ -122,18 +122,39 @@ p5.prototype.camera = function (...args) {
  * that are close to the camera appear their actual size while those
  * that are further away from the camera appear smaller.
  *
+ *
  * The parameters to this function define the viewing frustum
  * (the truncated pyramid within which objects are seen by the camera) through
  * vertical field of view, aspect ratio (usually width/height), and near and far
  * clipping planes.
  *
- * If no parameters are given, the following default is used:
- * perspective(PI/3, width/height, eyeZ/10, eyeZ*10),
- * where eyeZ is equal to ((height/2) / tan(PI/6)).
+ * If no parameters are given, the default values are used as:
+ *
+ *
+ * fov- The default field of view for the camera is such that the full height of renderer is visible when it is positioned at a default distance of 800 units from the camera.
+ *
+ * aspect- The default aspect ratio is the ratio of renderer's width to renderer's height.
+ *
+ * near - The default value for the near clipping plane is 0.1 times the default distance from the camera to the point it is looking at i.e 800.
+ *
+ * far - The default value for the far clipping plane is 10 times the default distance from the camera to the point it is looking at i.e 800.
+ *
+ * If you prefer a fixed field of view, follow these steps:
+ *
+ * 1.Choose your desired field of view angle (`fovy`). This is how wide the camera can see.
+ *
+ * 2.To position the camera correctly, use the formula:
+ *   cameraDistance = (height / 2) / tan(fovy / 2);
+ *   This ensures that you can see the entire width across horizontally and height across vertically at the fixed field of view.
+ *
+ * 3.Set the near value to  cameraDistance / 10 and the far value to  cameraDistance * 10 .
+ *
+ * 4.Simply, call perspective with the chosen field of view, canvas aspect ratio, and near/far values:
+ *    perspective(fovy, width / height, cameraDistance / 10, cameraDistance * 10);
  * @method  perspective
  * @for p5
  * @param  {Number} [fovy]   camera frustum vertical field of view,
- *                           from bottom to top of view, in <a href="#/p5/angleMode">angleMode</a> units
+ *                           from bottom to top of view, in <a href="#/p5/angleMode">angleMode</a> units.
  * @param  {Number} [aspect] camera frustum aspect ratio
  * @param  {Number} [near]   frustum near plane length
  * @param  {Number} [far]    frustum far plane length
@@ -156,7 +177,7 @@ p5.prototype.camera = function (...args) {
  *
  *   rotateX(-0.3);
  *   rotateY(-0.2);
- *   translate(0, 0, -50);
+ *   translate(0, 0, -100);
  *
  *   push();
  *   translate(-15, 0, sin(frameCount / 30) * 95);