计算着色器不修改3D纹理 [英] Compute shader not modifying 3d texture

问题描述

我想将3D纹理的初始化从CPU移到GPU.作为测试，我编写了一个着色器，将所有体素设置为恒定值，但是纹理根本没有被修改.我该如何运作?

I want to move the initialization of my 3D texture from the CPU to the GPU. As a test, I wrote a shader to set all voxels to a constant value, but the texture is not modified at all. How do I make it work?

计算着色器:

#version 430

layout(local_size_x=1, local_size_y=1, local_size_z=1) in;
layout(r8, location = 0) uniform image3D volume;

void main()
{
  imageStore(volume, ivec3(gl_WorkGroupID), vec4(0));
}

调用:

glEnable(GL_TEXTURE_3D);
glActiveTexture(GL_TEXTURE0);
glGenTextures(1, &volume_tid);
glBindTexture(GL_TEXTURE_3D, volume_tid);
glTexImage3D(GL_TEXTURE_3D, 0, GL_R8, volume_dims[0], volume_dims[1], volume_dims[2], 0, GL_RED, GL_UNSIGNED_BYTE, voxels);

ShaderProgram computeVolumeShader;
computeVolumeShader.loadShader(GL_COMPUTE_SHADER, "compute_volume.glsl");
computeVolumeShader.link();
computeVolumeShader.use();
computeVolumeShader.uniform("volume", 0);
glBindImageTexture(0, volume_tid, 0, GL_FALSE, 0, GL_READ_WRITE, GL_R8);
glDispatchCompute(volume_dims[0], volume_dims[1], volume_dims[2]);
glBindImageTexture(0, 0, 0, GL_FALSE, 0, GL_READ_WRITE, GL_R8);
computeVolumeShader.unUse();
glMemoryBarrier(GL_ALL_BARRIER_BITS);

注意:馈入glTexImage3D的voxels包含CPU初始化的数据.

Note: voxels fed into glTexImage3D contains the CPU initialized data.

推荐答案

U.因此，显然3D纹理必须绑定为分层，否则着色器无法使用w> 0修改任何uvw坐标.

Ugh. So apparently a 3D texture has to be bound as layered, otherwise the shader isn't able to modify any uvw coordinate with w>0.

glBindImageTexture(0, volume_tid, 0, /*layered=*/GL_TRUE, 0, GL_READ_WRITE, GL_R8);

起到了作用.

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