Reverse Z buffer

[voxelias]

What I want to achieve is a possibility of rendering of a huge objects (lets say an Island) from a large distance. I have a character on that island and I want to move camera far away from it to observe all the island. In other words I want to get rid of clipping effect of the projection matrix.

I've read that one possibility is to use reverse Z buffer. And here is a nice article about it.

But I am a bit lost, what should I do to achieve that in WGPU context and terms?
Any help and guidance would be very appreciated :)

[cwfitzgerald]

In terms of wgpu, all you need it to use a floating point depth buffer (Depth32Float). Then on the math end, you want your projection matrix to invert Z. A lot of graphics focused math libs can generate these (see for example, glam's Mat4::perspective_infinite_reverse_lh). What are you currently using to generate your projection matrix?

[kvark]

And also use GreaterEqual comparison in the depth-stencil state of the pipeline, of course :)

[voxelias]

Thank you for the response! I already use Depth32Float:

        let texture = wgpu::TextureDescriptor {
            label: Some("Depth Buffer"),
            size: buffer_extent,
            mip_level_count: 1,
            sample_count: 1,
            dimension: wgpu::TextureDimension::D2,
            format: wgpu::TextureFormat::Depth32Float,
            usage: wgpu::TextureUsage::SAMPLED
                | wgpu::TextureUsage::COPY_DST
                | wgpu::TextureUsage::RENDER_ATTACHMENT,
        };

Is that correct?

To generate my projection matrix at this moment I use cgmath but that is not an issue. I can change the lib or implement the matrix building function.

[kvark]

this looks fine

[voxelias]

Thank you, I will try different projection matrix!