Bevel or use normal maps in VR?

jordank95

Hey guys. I've been developing a VR project for a little bit and have a question about making assets for VR compared to assets for a regular game.

Is it better to just bevel edges instead of using normal maps to get smooth edges? I understand there's an increase in poly/vertex count, but when is beveling verse baking an advantage? I'm using normal maps for all the details, but unsure if I should also use normal maps for smooth edges.

NoRank

Well if you are already using a normal map for details, why not use for getting the smooth edges as well?

AlecMoody

The answer is that it depends. How far away will the object be? How many pixels of screen space is the edge going to take up? It is true that the stereo image can break the illusion of depth from a normal map but small edges don't produce a different enough image in each eye for it to matter.

jordank95

NoRank said:

Well if you are already using a normal map for details, why not use for getting the smooth edges as well?

Only for some of the assets. Some I have to decide if I'm going to use a normal map or bevel

AlecMoody said:

The answer is that it depends. How far away will the object be? How many pixels of screen space is the edge going to take up? It is true that the stereo image can break the illusion of depth from a normal map but small edges don't produce a different enough image in each eye for it to matter.

So if the object is close to the face, I should use a normal map? Further away, bevel?

musashidan

It's more about the viewing angle. There is no hard rule on this. R&D is the way to go. Setup some basic tests in the VR environment. Easy to do from right within the editor.

ActionDawg

jordank95 said:

So if the object is close to the face, I should use a normal map? Further away, bevel?

Nah he meant the opposite. As musashidan said viewing angle plays a large part of this. Also consider the depth of anything you're trying to normal map onto a surface. For instance a deep divot in a surface will look more like a flat decal if you just normal map it, especially when your viewing angle and the lighting line up just right to expose that the real surface is flat.

The less work you do through normal maps the more convincing the result.

ZacD

In VR, you basically shouldn't be using normal maps for details that have actual noticeable depth. Model those details in. Some bevels need to be modeled in, but you can get away with tiny bevels being in the normal map. 

Ruz

sorry for the Necro, but is it actually wise to use normal maps at all as I have a lot of bricks in my VR scene and they just look off with normal maps

ie they have a bumpy look, but just look wrong.

The depth of a brick is not too deep, but maybe even that does not work. I noticed in the Half Life Alyx home screen the bricks are not normal mapped

poopipe

The long and short of it is that normal maps can't carry as much weight in VR as they do on a flat screen but they do still work.

You don't want to try and fake geometric detail with them if you're getting close up cos it just won't work.

The further away an asset is from the player, the more you can get away with - the player can't put their head at a stupid angle and watch the parallax failing if they're far away

ZacD

https://polycount.com/discussion/comment/2770897#Comment_2770897

Looks like Alyx uses the pretty common approach of random sticking out bricks along the surface and corner pieces with a bunch of bricks.

Ruz

@poopipe yeah I had mixed results ie a tiling brick wall look ok as long as the spec was very low, but

form certain angles it looked klnd oif inside out ( viewpoint was from below) Floor looks ok with normal mapped bevels, but there is that sense that its all not quite right. - guess its because the left and right eye contradicts the normal map viewpoint or something

@ZacD yeah i noticed that and it looks pretty good still, that demo level is cool - shame the full game is a bit linear and lacks ammo :)

Graphically I have seen nothing better in vr though