The RenderDoc tool graphics debugger.

RenderDoc is a free MIT licensed stand-alone graphics debugger that allows quick and easy single-frame capture and detailed introspection of any application using Vulkan, D3D11, OpenGL & OpenGL ES or D3D12 across Windows 7 - 10, Linux, Android, Stadia, or Nintendo Switch™. RenderDoc can be used as an image viewer.
If you drag in or use file to open then you can open images in a variety of formats like: .dds, .hdr, .exr, .bmp, .jpg, .png, .tga, .gif, .psd.
The tool come with python A.P.I. for testing.
The full features can be found here.
You can see the geometry data visualized in 3D and with each component separated out and formatted.
This tool can be found at the official webpage.

Linux Graphics Debugger - version 2.0.

This article come with this new release about the new tool from NVIDIA named Linux Graphics Debugger. The development team tells us:

Linux Graphics Debugger is a 3D graphics development tool that allows developers to debug and profile OpenGL 4.x on Linux. It enables professional graphics developers to get the most out of their NVIDIA GeForce and Quadro GPUs on a variety of Linux distributions. This tool supports desktop class GPUs and inherits from the many man-years of investment in OpenGL development tools from the Tegra Graphics Debugger and NVIDIA® Nsight™ Visual Studio Edition.

System Requirements

Minimum supported Operating Systems for Linux Graphics Debugger:

• Ubuntu v12.04, v14.04, v16.04
• Redhat v6.5
• Centos v6.6

Supported Graphics APIs:

• OpenGL v4.2 - v4.5 core with over 100 extensions

Display Driver:

• Version 2.0 requires Linux driver version 370.23 or newer

gDEBugger - Now FREE!

A very popular OpenGL debugger is now available for FREE.
Named gDEBugger is an advanced OpenGL Debugger, Profiler and Graphic Memory Analyzer.
This 3D software saves you debugging time and helps you boost application performance.
We can download it from :here.