When you only want the color part of the frame, you can store depth in a render buffer.
This works fine for me on both webgl1 and webgl2.
When you also need to use the depth part you can't use a render buffer, you need to store it in a texture.
In webgl1 you need to get an extension to support it.
This also works fine for me in webgl1.
const gl = canvas.getContext('webgl');
const depthTextureExtension = gl.getExtension('WEBGL_depth_texture');
if (!depthTextureExtension) {
alert('Depth textures not supported');
}
This feature should be available by default in webgl2.
Yet when I replace the code above with this:
const gl = canvas.getContext('webgl2');
My code fails to render and I can not find any explanation why.
this.texture = gl.createTexture();
gl.bindTexture(gl.TEXTURE_2D, this.texture);
gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, width, height, 0, gl.RGBA, gl.UNSIGNED_BYTE, null);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR);
this.depth = gl.createTexture();
gl.bindTexture(gl.TEXTURE_2D, this.depth);
checkGLErrors(gl); // OK
gl.texImage2D(gl.TEXTURE_2D, 0, gl.DEPTH_COMPONENT, width, height, 0, gl.DEPTH_COMPONENT, gl.UNSIGNED_SHORT, null);
checkGLErrors(gl); // for webgl2: 1281 INVALID_VALUE
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR);
this.framebuffer = gl.createFramebuffer();
gl.bindFramebuffer(gl.FRAMEBUFFER, this.framebuffer);
gl.framebufferTexture2D(gl.FRAMEBUFFER, gl.COLOR_ATTACHMENT0, gl.TEXTURE_2D, this.texture, 0);
gl.framebufferTexture2D(gl.FRAMEBUFFER, gl.DEPTH_ATTACHMENT, gl.TEXTURE_2D, this.depth, 0);
In WebGL2 DEPTH_COMPONENT
is not a valid internal format. Use DEPTH_COMPONENT16
, DEPTH_COMPONENT24
or DEPTH_COMPONENT32F
Example from here
const level = 0;
const internalFormat = gl.DEPTH_COMPONENT24;
const border = 0;
const format = gl.DEPTH_COMPONENT;
const type = gl.UNSIGNED_INT;
const data = null;
gl.texImage2D(gl.TEXTURE_2D, level, internalFormat,
targetTextureWidth, targetTextureHeight, border,
format, type, data);