Throughout the week we begin working on the basic structure of our engine. Austin, Carter, and I were focusing on the VR portion of the engine. I was able to extract the basic initialization function from OpenVR’s API and startup the VR headset. However, the issue comes when we are trying to render to the headset. While we were able to render a specific texture/image onto the HMD (head-mounted display), we were unable to get our test object to render correctly in the scene, indicating there was a problem with our projection/view matrices.
Debugging and locating the issue was a bit of a process. With VR, debugging was tedious; the limited amount of hardware did not help the situation. We used an example project as the base model to sample our coding/math calculations off of. Thinking that there was a mistake with the math, I revisited the math functions used in our engine; however, the functions were tested to work correctly. Thus, the problem was not with the calculation but steps we took and how we interpret the data.
After some research, we realized that OpenVR operates and returns data in a right-handed column-major format. While we knew that the data we received comes in column major and our engine utilizes row major, we did not account for the fact that data from OpenVR are calculated under a right-handed system, whereas our engine uses a left-handed system.
Once I was able to figure out the proper conversion of a matrix from right-handed to left-handed and create the proper projection matrix, we were able to see the base cube object in the headset. A few adjustments are still needed to display accurately but we made decent progress towards of our engine.