我使用以下代码在 WebGL 中创建了一个帧缓冲区:
this.buffer = ctx.createFramebuffer();
ctx.bindFramebuffer(ctx.FRAMEBUFFER, this.buffer);
this.depthTexture = this.createTexture(ctx, ctx.DEPTH_COMPONENT,
ctx.DEPTH_COMPONENT, ctx.UNSIGNED_SHORT);
ctx.framebufferTexture2D(ctx.FRAMEBUFFER, ctx.DEPTH_ATTACHMENT,
ctx.TEXTURE_2D, this.depthTexture, 0);
this.colourTexture = this.createTexture(ctx, ctx.RGBA, ctx.RGBA, ctx.FLOAT);
ctx.framebufferTexture2D(ctx.FRAMEBUFFER, ctx.COLOR_ATTACHMENT0,
ctx.TEXTURE_2D, this.colourTexture, 0);
使用
this.ctx.useProgram(this.forwardShader.program);
this.ctx.bindFramebuffer(this.ctx.FRAMEBUFFER, this.framebuffer.buffer);
this.ctx.viewport(0, 0, this.framebuffer.size, this.framebuffer.size);
this.ctx.clear(this.ctx.COLOR_BUFFER_BIT | this.ctx.DEPTH_BUFFER_BIT);
mat4.identity(this.viewMatrix);
mat4.identity(this.modelMatrix);
this.camera.transform(this.viewMatrix);
mat4.translate(this.modelMatrix, this.modelMatrix, [0, 0, -2]);
this.mStack.pushMatrix(this.modelMatrix);
mat4.translate(this.modelMatrix, this.modelMatrix, [0, -1, 0]);
mat4.rotateX(this.modelMatrix, this.modelMatrix, -Math.PI / 2.0);
this.setShaderUniforms();
this.plane.draw(this.forwardShader);
this.mStack.popMatrix(this.modelMatrix);
this.setShaderUniforms();
this.cube.draw(this.forwardShader);
this.ctx.bindFramebuffer(this.ctx.FRAMEBUFFER, null);
然后使用渲染结果
this.ctx.useProgram(this.renderTextureShader.program);
this.ctx.viewport(0, 0, this.viewportWidth, this.viewportHeight);
this.ctx.clear(this.ctx.COLOR_BUFFER_BIT | this.ctx.DEPTH_BUFFER_BIT);
this.renderTexture.draw(this.framebuffer.colourTexture, this.renderTextureShader);
效果很好,但是当我将其更改为渲染深度纹理时,我得到一个白屏。我已经检查了相关的扩展是否已启用并将它们存储在一个数组中(显然,如果它们被 gc'ed 它可能会导致错误。任何关于我做错了什么的反馈都会很棒
完整代码可以在我的bitbucket上找到