Need guidance regarding lighting for large engineering models

[anonymous_user_c9aca388]

Thanks for the assistance.

@anonymous_user_fc6e0fe5

First of all, having THOUSANDS of individual Meshes is going to kill your performance as your DrawCalls will skyrocket. You absolutely have to pack large amounts of them together or you will not get any good performance which is essential for VR.

So are you referring to an overhead from all the DrawCalls? I imagine a mesh with multiple parts is going to take longer to process than tiny individual meshes, but if it is overhead that is being saved, then I guess it is worth exploring.

How should I group these meshes? Is it better to group objects that are close together, or group similar shapes that may have a lot of clear space between them? And will the auto-generated UV maps be okay with these grouped meshes?

@anonymous_user_fc6e0fe5

Depending on how highres your shadows will be it’s absolutely possible to shadowmap a large mesh. In the end, it’s always about your target hardware. Again, you can split up that terrain into parts.

Shadowmap, as in baked lighting? The problem is even with a small test model I am using now with 1500 parts, and a floor mesh that is 160x130 meters with light map res set to 2048, the shadows on the floor still look blocky. However, I have just discovered I can use stationary directional light, and by setting a value to Dynamic Shadow Distance Stationary Light, I am getting dynamic shadows up close, which fall back to baked in the background. This looks promising.

@anonymous_user_fc6e0fe5

What most likely won’t work is 200% Screenpercentage, Forward Shading AND Dynamic Lighting. For VR to work you have to cut corners, think out of the box. Most VR projects use static lighting wherever they can because it’s increadibly cheap, once baked. Dynamic Shadows and VR are not a good idea and should be used in small scale cases, if at all.

The screen percentage doesn’t seem to make a lot of difference to performance on my test model. Unfortunately the CPU (a xeon with only 2.2GHz cores) isn’t keeping up, and is doing 16ms frames according ot SteamVR stats. The GTX 1080 seems to be doing alright though. End result, it runs solid at the 45fps that the VR hardware drops down to.

My small model is using 3Gb vram with baked lighting. I guess I’ll have to try a bigger model with 10k+ parts, to see how it goes. Right now I am only using simple colored materials too.