在 THREE.js 中的顶点着色器之后获得变换的顶点位置

本文介绍了在 THREE.js 中的顶点着色器之后获得变换的顶点位置的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！

问题描述

我正在更改顶点着色器中某些顶点的位置，但我找不到将这些新更新的顶点位置放回到 js 中的方法(我目前正在使用 THREE.js:网格顶点的顶点位置)始终保持不变).我找到了这个链接 Retrieve Vertices Data in THREE.js，但 glGetTexImage 没有t 存在于 webgl 中(我也对这种浮点纹理方法持怀疑态度).感谢您的帮助！

I am changing the positions of some vertices inside a vertex shader but i can't find a way to get those new updated vertices positions back inside js (i'm currently using THREE.js : the vertex position of my mesh's vertices always remains the same).I found this link Retrieve Vertices Data in THREE.js, but glGetTexImage doesn't exist in webgl (and i'm quite skeptical about this floating-point texture method as well).Thanks for your help !

推荐答案

如果从缓冲区读取数据是唯一的问题，你可以这样做:

If reading the data from the buffer is the only problem, you can do that like this:

//render the pass into the buffer
renderer.render( rttScene, rttCamera, rttTexture, true );

// ...


//allocate an array to take the data from the buffer
var width = rttTexture.width;
var height = rttTexture.height;
var pixels = new Uint8Array(4 * width * height);


//get gl context bind buffers, read pixels
var gl = renderer.context;
var framebuffer = rttTexture.__webglFramebuffer;
gl.bindFramebuffer(gl.FRAMEBUFFER, framebuffer);
gl.viewport(0, 0, width, height);
gl.readPixels(0, 0, width, height, gl.RGBA, gl.UNSIGNED_BYTE, pixels);
gl.bindFramebuffer(gl.FRAMEBUFFER, null);

WebGL - 从渲染缓冲区读取像素数据

但是设置起来很复杂，读取纹理可能很慢，为什么不在 cpu 上做呢?

But setting all this up is complicated, and reading the texture might be slow, why not do this on the cpu?

这篇关于在 THREE.js 中的顶点着色器之后获得变换的顶点位置的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！

retrieve