WebGL渲染到cubetexture错误1282 - “没有绑定到单元0的纹理”

Question

我正在尝试将一个小场景渲染到立方体贴图中以用于WebGL中的反射 - 使用Emscripten（ C ++ to JavaScript ）。我的代码只是通过6个面，并将所有对象渲染到立方体纹理的当前绑定侧。该代码适用于桌面构建，没有错误。但是WebGL说：

RENDER警告：没有纹理绑定到单位0。

在用glGetError（）检查后，我得到错误1282;当我打电话给“glDrawElements”时。两条消息都出现30次（将5个网格渲染为6个面 - 6 * 5 = 30）

Fbo＆amp;纹理创作

    glGenFramebuffers(1, &m_FboId);
    glBindFramebuffer(GL_FRAMEBUFFER, m_FboId);

    glGenTextures(1, &m_glId);
    glBindTexture(GL_TEXTURE_CUBE_MAP, m_glId);

    for (unsigned int i = 0; i < 6; i++)
        glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X + i, 0, GL_RGB, CUBEMAP_SIZE, CUBEMAP_SIZE, 0, GL_RGB, GL_FLOAT, nullptr);

    glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
    glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
    glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

#if !WEB
    glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_EDGE); // Wrap_R is invalid in WebGL
#endif

    glBindTexture(GL_TEXTURE_CUBE_MAP, 0);

    glGenRenderbuffers(1, &m_DepthId);
    glBindRenderbuffer(GL_RENDERBUFFER, m_DepthId);

    glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT16, CUBEMAP_SIZE, CUBEMAP_SIZE);
    glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, m_DepthId);

    m_DrawBuffers[0] = GL_COLOR_ATTACHMENT0;
    glDrawBuffers(1, m_DrawBuffers);

    int fbo_Status = glCheckFramebufferStatus(GL_FRAMEBUFFER);
    if (fbo_Status != GL_FRAMEBUFFER_COMPLETE) printf(" ::ENGINE:: FBO Creation Failed! glError: %i\n", fbo_Status);

    glBindRenderbuffer(GL_RENDERBUFFER, 0);
    glBindFramebuffer(GL_FRAMEBUFFER, 0);

渲染：

    glBindFramebuffer(GL_FRAMEBUFFER, m_FboId);
    glViewport(0, 0, CUBEMAP_SIZE, CUBEMAP_SIZE);

    Object* objectPtr;

    shader.bind();
    shader.loadProjectionMtx(math::perspective(90.0f, 1.0f, 0.001f, 300.0f)[0][0]);
    shader.loadCameraPosition(m_Position.x, m_Position.y, m_Position.z);

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    math::mat4 viewMtx(1.0f);

    for (unsigned int f = 0; f < 6; f++)
    {
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_CUBE_MAP_POSITIVE_X + f, m_glId, 0);
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

        if (f == 2)
            viewMtx = math::lookAt(m_Position, m_Position - math::vec3( 0.0f, -1.0f,  0.0f), math::vec3(0.0f, 0.0f, 1.0f));
        else if (f == 1)
            viewMtx = math::lookAt(m_Position, m_Position - math::vec3( 1.0f,  0.0f,  0.0f), math::vec3(0.0f, -1.0f, 0.0f));
        else if (f == 4)
            viewMtx = math::lookAt(m_Position, m_Position - math::vec3( 0.0f,  0.0f, -1.0f), math::vec3(0.0f, -1.0f, 0.0f));
        else if (f == 3)
            viewMtx = math::lookAt(m_Position, m_Position - math::vec3( 0.0f,  1.0f,  0.0f), math::vec3(0.0f, 0.0f, -1.0f));
        else if (f == 0)
            viewMtx = math::lookAt(m_Position, m_Position - math::vec3(-1.0f,  0.0f,  0.0f), math::vec3(0.0f, -1.0f, 0.0f));
        else if (f == 5)
            viewMtx = math::lookAt(m_Position, m_Position - math::vec3( 0.0f,  0.0f,  1.0f), math::vec3(0.0f, -1.0f, 0.0f));

        shader.loadViewMtx(viewMtx[0][0]);

        for (unsigned int i = 0; i < m_Entities.size(); i++)
        {
            shader.loadModelMtx(m_Entities[i]->getMtx()[0][0]);

            objectPtr = static_cast<Object*>(m_Entities[i]);

            for (int t = 0; t < 3; t++)
            {
                glActiveTexture(GL_TEXTURE0 + t);
                glBindTexture(GL_TEXTURE_2D, objectPtr->getTextureId(t));
                glUniform1i(objectPtr->getUniformLoc(t), t);
            }

            glBindVertexArray(objectPtr->getMesh()->getVao());
            int error = glGetError();
            glDrawElements(GL_TRIANGLES, objectPtr->getMesh()->getNumberOfIndices(), GL_UNSIGNED_SHORT, 0);
            error = glGetError(); if (error != 0) printf("GL ERROR: %i\n", error);
            glBindVertexArray(0);
        }
    }

    glBindFramebuffer(GL_FRAMEBUFFER, 0);

我在这里做了什么，WebGL不喜欢？这正是我在将2D纹理渲染到另一个FBO时渲染场景的方式。唯一不同的是，这次，我正在渲染成立方体纹理。