Python Script: gpu.types.GPUTexture not loading cubemap faces correctly #120068

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NathanMiller · 2024-03-29T16:59:31+01:00

NathanMiller commented

2024-03-29 16:59:31 +01:00

System Information
Operating system: Windows-10-10.0.19045-SP0 64 Bits
Graphics card: NVIDIA GeForce RTX 3060 Ti/PCIe/SSE2 NVIDIA Corporation 4.6.0 NVIDIA 551.23

Blender Version
Broken: version: 4.0.2, branch: blender-v4.0-release, commit date: 2023-12-05 07:41, hash: 9be62e85b727
Worked: No build found that works

Tried blender 3.3 and latest daily ( 4.2.0 Alpha, branch: main, commit date: 2024-03-29 14:05, hash: a78d4f31be67) aswell

Short description of error
I am trying to load a cubemap through a use of a gpu.types.GPUTexture in python.
Blender however only seems to have loaded the first cubemap face, regardless of the direction given in glsl.

Exact steps for others to reproduce the error
I have added a blend with the script with the issue. All faces set as red aside for the first one which is a pink color. Adjusting the direction in the glsl code texture(cube_map, vec3(0, 0, 1)) will always result in the pink color when red is expected.

Full code here.

import gpu
from gpu_extras.batch import batch_for_shader
import numpy as np

#Setup a 64x64 cubemap, all red faces expect the first one
cubemap_face_size = 64 * 64 * 4
cubemap_size = cubemap_face_size * 6 

cubemap_pixels = np.empty(cubemap_size, dtype=np.float32)
num_pixels_per_face = 64 * 64

for i in range(6):
    start_index = i * cubemap_face_size
    end_index = (i + 1) * cubemap_face_size
    if i == 0:  # First face
        cubemap_pixels[start_index:end_index] = [1.0, 0.0, 1.0, 1.0] * num_pixels_per_face   # Pink
    else:
        cubemap_pixels[start_index:end_index] = [1.0, 0.0, 0.0, 1.0] * num_pixels_per_face # Red

buffer = gpu.types.Buffer('FLOAT', cubemap_size)
buffer[:] = cubemap_pixels

#make gpu texture
gpuImage = gpu.types.GPUTexture(size=64,
                             is_cubemap=True, format='RGBA32F',
                             data=buffer)

shader_info = gpu.types.GPUShaderCreateInfo()
shader_info.push_constant('MAT4', "viewProjectionMatrix")
shader_info.vertex_in(0, 'VEC3', "position")
shader_info.fragment_out(0, 'VEC4', "FragColor")
shader_info.sampler(0, 'FLOAT_CUBE', "cube_map")

shader_info.vertex_source(
    "void main()"
    "{"
    "  gl_Position = viewProjectionMatrix * vec4(position, 1.0f);"
    "}"
)

shader_info.fragment_source(
    "void main()"
    "{"
    "  vec4 cube = texture(cube_map, vec3(0, 0, 1));" #Uses a fixed direction. Same color either direction given
    "  FragColor = vec4(cube.rgb, 1.0);"
    "}"
)

shader = gpu.shader.create_from_info(shader_info)
del shader_info

batch = batch_for_shader(shader, 'TRIS', 
{
    "position": (
    (-1, -1, 1),
    (-1, 1, 1),
    (1, 1, 1),
    
    (1, 1, 1),
    (1, -1, 1),
    (-1, -1, 1)),
})


def draw():
    matrix = bpy.context.region_data.perspective_matrix
    shader.uniform_float("viewProjectionMatrix", matrix)
    shader.uniform_sampler("cube_map", gpuImage)

    batch.draw(shader)


bpy.types.SpaceView3D.draw_handler_add(draw, (), 'WINDOW', 'POST_VIEW')

**System Information** Operating system: Windows-10-10.0.19045-SP0 64 Bits Graphics card: NVIDIA GeForce RTX 3060 Ti/PCIe/SSE2 NVIDIA Corporation 4.6.0 NVIDIA 551.23 **Blender Version** Broken: version: 4.0.2, branch: blender-v4.0-release, commit date: 2023-12-05 07:41, hash: `9be62e85b727` Worked: No build found that works Tried blender 3.3 and latest daily ( 4.2.0 Alpha, branch: main, commit date: 2024-03-29 14:05, hash: `a78d4f31be67`) aswell **Short description of error** I am trying to load a cubemap through a use of a gpu.types.GPUTexture in python. Blender however only seems to have loaded the first cubemap face, regardless of the direction given in glsl. **Exact steps for others to reproduce the error** I have added a blend with the script with the issue. All faces set as red aside for the first one which is a pink color. Adjusting the direction in the glsl code `texture(cube_map, vec3(0, 0, 1))` will always result in the pink color when red is expected. Full code here. ```py import bpy import gpu from gpu_extras.batch import batch_for_shader import numpy as np #Setup a 64x64 cubemap, all red faces expect the first one cubemap_face_size = 64 * 64 * 4 cubemap_size = cubemap_face_size * 6 cubemap_pixels = np.empty(cubemap_size, dtype=np.float32) num_pixels_per_face = 64 * 64 for i in range(6): start_index = i * cubemap_face_size end_index = (i + 1) * cubemap_face_size if i == 0: # First face cubemap_pixels[start_index:end_index] = [1.0, 0.0, 1.0, 1.0] * num_pixels_per_face # Pink else: cubemap_pixels[start_index:end_index] = [1.0, 0.0, 0.0, 1.0] * num_pixels_per_face # Red buffer = gpu.types.Buffer('FLOAT', cubemap_size) buffer[:] = cubemap_pixels #make gpu texture gpuImage = gpu.types.GPUTexture(size=64, is_cubemap=True, format='RGBA32F', data=buffer) shader_info = gpu.types.GPUShaderCreateInfo() shader_info.push_constant('MAT4', "viewProjectionMatrix") shader_info.vertex_in(0, 'VEC3', "position") shader_info.fragment_out(0, 'VEC4', "FragColor") shader_info.sampler(0, 'FLOAT_CUBE', "cube_map") shader_info.vertex_source( "void main()" "{" " gl_Position = viewProjectionMatrix * vec4(position, 1.0f);" "}" ) shader_info.fragment_source( "void main()" "{" " vec4 cube = texture(cube_map, vec3(0, 0, 1));" #Uses a fixed direction. Same color either direction given " FragColor = vec4(cube.rgb, 1.0);" "}" ) shader = gpu.shader.create_from_info(shader_info) del shader_info batch = batch_for_shader(shader, 'TRIS', { "position": ( (-1, -1, 1), (-1, 1, 1), (1, 1, 1), (1, 1, 1), (1, -1, 1), (-1, -1, 1)), }) def draw(): matrix = bpy.context.region_data.perspective_matrix shader.uniform_float("viewProjectionMatrix", matrix) shader.uniform_sampler("cube_map", gpuImage) batch.draw(shader) bpy.types.SpaceView3D.draw_handler_add(draw, (), 'WINDOW', 'POST_VIEW') ``` ![image](/attachments/95e5ae5b-0d52-4e02-b05b-6f22d9b36e8a)

CubemapGpuTextureScript.blend

828 KiB

image.png

82 KiB

NathanMiller added the

labels 2024-03-29 16:59:32 +01:00

Germano Cavalcante commented

2024-03-29 21:57:27 +01:00

I can confirm that, no mater the direction set in the fragment shader, the color retrieved of the cube_map texture is always the color of the first face (the pink one).

vec4 cube = texture(cube_map, vec3(0, 0, 1));

@fclem, can you identify if there is something in the script that could result in this behavior or if it is really a bug?

I can confirm that, no mater the direction set in the fragment shader, the color retrieved of the cube_map texture is always the color of the first face (the pink one). ```glsl vec4 cube = texture(cube_map, vec3(0, 0, 1)); ``` @fclem, can you identify if there is something in the script that could result in this behavior or if it is really a bug?

Germano Cavalcante added

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Python Script: gpu.types.GPUTexture not loading cubemap faces correctly #120068