**Exploring glow effects in rendering**

I'm considering adding glow effects through post-processing, but I can't use external libraries. One idea is to create the glow with multiple thick lines, employing transparency and additive blending using ShaderMaterial. Also, I’d like to render points with gl.POINTS for a glowing effect. I want to visualize a 3D butterfly trajectory over time by computing Lorenz points and updating the attributes gradually, using various techniques to manage opacity and blending effectively.**Looking into rendering techniques**

I'm exploring an alternative method to render glowing effects by using points with size and additive blending. I can utilize gl.POINTS and adjust gl_PointCoord in the fragment shader to create a radial gradient. Implementing a points-based attractor with Lorenz equations sounds intriguing, especially with attributes for size and age index. I also want to consider camera controls, establish a UI for playback options, and add a background gradient while keeping everything visually appealing with color transitions. Plus, implementing resizing will enhance user experience!**Computing Lorenz points**

I'm planning to compute Lorenz points using typical parameters like sigma=10, rho=28, and beta=8/3, starting from an initial point with a small offset. For integration, I'll opt for Runge-Kutta 4 due to its stability. I want to set the number of points, perhaps around 20,000, and create a precomputed positions array as a Float32Array. I’ll also need to compute an indices array and possibly assign colors per vertex, either directly or calculated in the shader based on their z-value or index.**Shader specifications**

I’m working on the vertex shader first, which includes attributes for aIndex and position, along with uniforms like uProgress, uPointSize, and uTotal. I’ll compute a normalized index and handle the fading effect based on age using smoothstep for alpha. The gl_PointSize will adjust depending on distance.

For the fragment shader, I’ll create a radial gradient by calculating distance from the center point, blending colors with smoothstep for a soft disc effect. Finally, I'll apply additive blending with transparency, ensuring depth writing is false for a glowing appearance.**Setting up rendering attributes**

I need to define an attribute aIndex as a float array for each vertex while keeping the positions attribute normal. I'll update the uniform uProgress in the render loop, adjusting it by speed times delta. This loop should manage progress from 0 to totalPoints, and I'll loop back or keep drawing a persistent tail.

For visual interest, I’m thinking of creating multiple point clouds with various sizes and colors to simulate a glow effect. I could render two point meshes: one with a large size and bright color, and another smaller. Implementing two shader materials for this sounds good! 

Additionally, I plan to add subtle camera auto-rotation when idle, with mouse drag and wheel event handlers. I also want a UI overlay with controls in the top-left. Plus, I need to carefully reference attributes when writing the index.html file. I’ll ensure gl_PointCoord is set in the fragment shader too! 

Alright, let's dive into coding that index.html file!