I have been using VT on 2021.1f9 HDRP11 on an open world project for the last year. I have been using VT since it came out (on and off) and now my project fully uses it all the time.
I would like to provide a detailed feedback of my experience and hopefully be able to share important notes about the new tech.
So why do I need VT?
Well my project is an open world game, innately having towns in an open environment. This means that even with careful level placement and occlusion, some angles, parts of the map will present more texture than others. For example, a town. So, working with 4k~8k textures, and given that HDRP uses 3 maps on standard, reaching 50+ 4k maps was very easy with few props and walls placed. This, essentially floods the GPU pipeline and causes a massive lag until the texture is uploaded.
Isn’t texture streaming enough?
Yes, and no. While texture streaming improves the lag situation and the saturated GPU pipe, VRAM use starts to go up out of control and this is for a small town with not much props.
So, then, VT.
Yes, VT, solves all this issue, and to my surprise, it just works and this is not a deal you get everyday in the Unity eco system. I can easily run 4k~8k textures upwards of 100+ maps as long as they are well placed.
Is the VT ready for production?
Yes and no. Yes, in the sense of stability. It is stable, and works as expected. And like I said above, this is big.
And No, in the sense that it lacks some basic features that should have been included from the beginning.
What exactly is missing?
I am not going to mention QOL improvements as they are just conveniences. But the issue that I am about to share is critical and renders the tech “not ready”. In my opinion, there is only one real issue with VT at the moment, one which needs to be addressed immediately.
So what is it?
When VT is loading in, instead of showing the lowest level mip map (like every other VT solution), Unity’s VT just shows black color until it loads in. And this is what it looks like.
This pop in from black color → texture is very noticeable as it mostly happens close up. It mostly occurs when entering/exiting a room and unless there is a one way type of corridor, this is hard to workaround. This probably will make my players very very unhappy - no doubt.
So, devs, please fix this asap.
Here is a visualization of what I think it should look like. Instead of black color, lowest level mip map is loaded in first → then vt texture. I am think maybe at shader level, lowest mip map can be shown (not as vt) if vt texture is not ready.