How do I render an obj mesh in my Raytracer?

This comment was posted to reddit on Jun 02, 2021 at 8:48 pm and was deleted within 9 hour(s) and 10 minutes.

First, you need to parse an OBJ file to obtain the triangles, fortunately it's super simple and you can write your own in like 10-20 minutes.
You can get some obj files here: https://github.com/alecjacobson/common-3d-test-models/blob/master/data/xyzrgb_dragon.obj
Those obj files need to be edited a bit, since some of them are scaled small, some are too big. You can use Maya.
Each triangle is a Hittable, so a triangle mesh is a HittableList
The biggest problem is the performance, you will have so many triangles can't you need to implement BVH, so you need to implement one described in RayTracing The Next Week
After you implement the BVH, your raytracer will be still slow, so implement a multithread raytracing, this part is probably quite tricky to implement but there are many examples available using std::thread or std::future/std::async.

Good luck!