Qt Quick3D skybox fails on android

johngod

I have made a small example that shows a skybox. It works fine on desktop but fails on android. The code is simple:

import QtQuick 2.12
import QtQuick.Window 2.12
import QtQuick3D 1.15

Window {
    visible: true
    width: 640
    height: 480
    title: qsTr("Hello World")

    View3D {
        id: view3D
        visible: true
        width: parent.width
        height: parent.height

        environment: SceneEnvironment {
            //backgroundMode: SceneEnvironment.Color
            backgroundMode:  SceneEnvironment.SkyBox
            lightProbe: Texture {
                source: "qrc:/skybox.hdr"
                mappingMode: Texture.LightProbe
            }
            clearColor: "skyblue"
        }

        //! [camera]
        PerspectiveCamera {
            id: cam
            position: Qt.vector3d(0, 0, 500)
        }
        //! [camera]


        DirectionalLight {
            eulerRotation.x: -45
        }

        Model {
            id: ball
            //source: "#Cylinder"
            source: "#Cylinder"
            scale: Qt.vector3d(1, 1, 1)
            materials: [ DefaultMaterial {
                    diffuseColor: "red"
                }
            ]
            position: Qt.vector3d(-100, -150, 0)
            onPositionChanged: console.log(position)
        }
    }
}

Relevant part of the logs:

I Adreno  : QUALCOMM build                   : e6de3b7, I22091d40c2
I Adreno  : Build Date                       : 08/07/19
I Adreno  : OpenGL ES Shader Compiler Version: EV031.25.03.03
............
I OpenGLRenderer: Initialized EGL, version 1.4
D OpenGLRenderer: Swap behavior 2
D OpenGLRenderer: eglCreateWindowSurface = 0xa52a1120, 0x920c6808
..............................
I libSkyBoxTest_armeabi-v7a.so: QSSG.trace_info: GLSL version: OpenGL ES GLSL ES 3.10
I libSkyBoxTest_armeabi-v7a.so: QSSG.trace_info: GL version: OpenGL ES 3.0 V@331.0 (GIT@e6de3b7, I22091d40c2) (Date:08/07/19)
I libSkyBoxTest_armeabi-v7a.so: QSSG.trace_info: HW vendor: Qualcomm
I libSkyBoxTest_armeabi-v7a.so: QSSG.trace_info: Vendor renderer: Adreno (TM) 308
I libSkyBoxTest_armeabi-v7a.so: QSSG.trace_info: OpenGL extensions: GL_OES_EGL_image GL_OES_EGL_image_external GL_OES_EGL_sync GL_OES_vertex_half_float GL_OES_framebuffer_object GL_OES_rgb8_rgba8 GL_OES_compressed_ETC1_RGB8_texture GL_AMD_compressed_ATC_texture GL_OES_texture_npot GL_EXT_texture_filter_anisotropic GL_EXT_texture_format_BGRA8888 GL_OES_texture_3D GL_EXT_color_buffer_float GL_EXT_color_buffer_half_float GL_QCOM_alpha_test GL_OES_depth24 GL_OES_packed_depth_stencil GL_OES_depth_texture GL_OES_depth_texture_cube_map GL_EXT_sRGB GL_OES_texture_half_float GL_OES_texture_half_float_linear GL_EXT_texture_type_2_10_10_10_REV GL_EXT_texture_sRGB_decode GL_OES_element_index_uint GL_QCOM_user_clip_planes GL_EXT_EGL_image_external_wrap_modes GL_EXT_multisampled_render_to_texture GL_EXT_robustness GL_OES_get_program_binary GL_EXT_debug_label GL_QCOM_tiled_rendering GL_OES_standard_derivatives GL_OES_vertex_array_object GL_EXT_YUV_target GL_EXT_sRGB_write_control GL_EXT_discard_framebuffer GL_OES_surfaceless_context GL_KHR_no_error GL_EX
I libSkyBoxTest_armeabi-v7a.so: QSSG.trace_info: GL version: OpenGL ES 3.0 V@331.0 (GIT@e6de3b7, I22091d40c2) (Date:08/07/19)
I libSkyBoxTest_armeabi-v7a.so: QSSG.trace_info: Compiling into shader cache: ' "fullscreen skybox shader" >'
I Adreno  : ERROR: 0:19: 'inverse' : no matching overloaded function found
I Adreno  : ERROR: 0:19: '=' :  cannot convert from 'const float' to '4X4 matrix of float'
I Adreno  : ERROR: 2 compilation errors.  No code generated.
06-21 07:33:48.481 31533 31709 I Adreno  :
E libSkyBoxTest_armeabi-v7a.so: QSSG.internal_error: Failed to generate vertex shader!!
E libSkyBoxTest_armeabi-v7a.so: QSSG.internal_error: Vertex source:
E libSkyBoxTest_armeabi-v7a.so: #version 100
E libSkyBoxTest_armeabi-v7a.so: #extension GL_OES_standard_derivatives : enable
E libSkyBoxTest_armeabi-v7a.so: precision mediump float;
E libSkyBoxTest_armeabi-v7a.so: precision mediump int;
E libSkyBoxTest_armeabi-v7a.so: #define texture texture2D
E libSkyBoxTest_armeabi-v7a.so: #define textureLod(s, co, lod) texture2D(s, co)
E libSkyBoxTest_armeabi-v7a.so: //Shader name -fullscreen skybox shader
06-21 07:33:48.481 31533 31709 E libSkyBoxTest_armeabi-v7a.so:
E libSkyBoxTest_armeabi-v7a.so: attribute vec3 attr_pos;
06-21 07:33:48.481 31533 31709 E libSkyBoxTest_armeabi-v7a.so:
E libSkyBoxTest_armeabi-v7a.so: uniform mat4 viewMatrix;
E libSkyBoxTest_armeabi-v7a.so: uniform mat4 projection;
06-21 07:33:48.481 31533 31709 E libSkyBoxTest_armeabi-v7a.so:
06-21 07:33:48.481 31533 31709 E libSkyBoxTest_armeabi-v7a.so:
E libSkyBoxTest_armeabi-v7a.so: varying vec3 eye_direction;
06-21 07:33:48.481 31533 31709 E libSkyBoxTest_armeabi-v7a.so:
E libSkyBoxTest_armeabi-v7a.so: void main() {
E libSkyBoxTest_armeabi-v7a.so:     gl_Position = vec4(attr_pos, 1.0);
E libSkyBoxTest_armeabi-v7a.so:     mat4 inverseProjection = inverse(projection);
E libSkyBoxTest_armeabi-v7a.so:     vec3 unprojected = (inverseProjection * gl_Position).xyz;
E libSkyBoxTest_armeabi-v7a.so:     eye_direction = normalize(mat3(viewMatrix) * unprojected);
E libSkyBoxTest_armeabi-v7a.so: }
06-21 07:33:48.481 31533 31709 E libSkyBoxTest_armeabi-v7a.so:
E libSkyBoxTest_armeabi-v7a.so: QSSG.invalid_operation: Vertex compilation output:: ERROR: 0:19: 'inverse' : no matching overloaded function found
E libSkyBoxTest_armeabi-v7a.so: QSSG.invalid_operation: Vertex compilation output:: ERROR: 0:19: '=' :  cannot convert from 'const float' to '4X4 matrix of float'
E libSkyBoxTest_armeabi-v7a.so: QSSG.invalid_operation: Vertex compilation output:: ERROR: 2 compilation errors.  No code generated.
E libSkyBoxTest_armeabi-v7a.so: QSSG.invalid_operation: Vertex compilation output::
E libSkyBoxTest_armeabi-v7a.so: QSSG.invalid_operation: Vertex compilation output::
W project.exampl: 0xebadde09 skipped times: 0
F libc    : Fatal signal 11 (SIGSEGV), code 1 (SEGV_MAPERR), fault addr 0x4 in tid 31709 (QtThread), pid 31533 (project.example)

From above the problem seems to be the inverse() function in the auto generated shader:

#version 100
#extension GL_OES_standard_derivatives : enable
precision mediump float;
precision mediump int;
#define texture texture2D
#define textureLod(s, co, lod) texture2D(s, co)
//Shader name -fullscreen skybox shader

attribute vec3 attr_pos;

uniform mat4 viewMatrix;
uniform mat4 projection;
varying vec3 eye_direction;


void main() {
    gl_Position = vec4(attr_pos, 1.0);
    mat4 inverseProjection = inverse(projection);
    vec3 unprojected = (inverseProjection * gl_Position).xyz;
    eye_direction = normalize(mat3(viewMatrix) * unprojected);
}

According to the Khronus group the inverse() its only available in OpenGL ES shader language version 3.00. This seems to be a Qt bug, the auto generated preprocessor shader should be "#version 300 es", not "#version 100". Also I check my android phone it has opengl es 3.0 so it's good to go. As a workaround I could try to write my own shader but I thing thats only possible for custom Model's, not for SceneEnvironment.
Somebody as any better ideia how to fix ???

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Qt Quick3D skybox fails on android