How to do ray tracing in modern OpenGL?

user_277716 0
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So I'm at a point that I should begin lighting my flatly colored models. The test application is a test case for the implementation of only latest methods so I realized that ideally it should be implementing ray tracing (since theoretically, it might be ideal for real time graphics in a few years).

But where do I start?

Assume I have never done lighting in old OpenGL, so I would be going directly to non-deprecated methods.

The application has currently properly set up vertex buffer objects, vertex, normal and color input and it correctly draws and transforms models in space, in a flat color.

Is there a source of information that would take one from flat colored vertices to all that is needed for a proper end result via GLSL? Ideally with any other additional lighting methods that might be required to complement it.

opengl-3 raytracing glsl opengl
6 Answers

As for 2019 Ray tracing is an option for real time rendering but requires high end GPUs most users don't have. Some of these GPUs are designed specifically for Ray tracing. OpenGL currently does not support hardware boosted Ray tracing. DirectX 12 on windows does have support for it. It is recommended to wait a few more years before creating a Ray tracing only renderer although it is possible using DirectX 12 with current desktop and laptop hardware. Support from mobile may take decades. I don't see openGL supporting ray tracing but vulkan could in the future support it.

user_106637320

I found some of the other answers to be verbose and wordy. For visual examples that YES, functional ray tracers absolutely CAN be built using the OpenGL API, I highly recommend checking out some of the projects people are making on https://www.shadertoy.com/ (Warning: lag)

user_91018590

Opengl (glsl) can be used for ray (path) tracing. however there are few better options: Nvidia OptiX (Cuda toolkit -- cross platform), directx 12 (with Nvidia ray tracing extension DXR -- windows only), vulkan (nvidia ray tracing extension VKR -- cross platform, and widely used), metal (only works on MacOS), falcor (DXR, VKR, OptiX based framework), Intel Embree (CPU ray tracing only).

user_59379780

To answer the topic: OpenGL has no RTX extension, but Vulkan has, and interop is possible. Example here: https://github.com/nvpro-samples/gl_vk_raytrace_interop

As for the actual question: To light the triangles, there are tons of techniques, look up for "forward", "forward+" or "deferred" renderers. The technique to be used depends on you goal. The simplest and most good-looking these days, is image based lighting (IBL) with physically based shading (PBS). Basically, you use a cubemap and blur it more or less depending on the glossiness of the object. For a simple object viewer you don't need more.

user_112353520
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