Shadow volume?

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crowbarscientist
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Joined: 10 Jul 2020, 10:08

Shadow volume?

Post by crowbarscientist » 10 Jul 2020, 10:20

Why is there no shadow volumes in OpenMW like there is in vanilla Morrowind? Would it not look better and perform faster than the shadows used in OpenMW 0.46.0 since the shadows are sharp (and "jaggy") anyways?

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AnyOldName3
Posts: 1946
Joined: 26 Nov 2015, 03:25

Re: Shadow volume?

Post by AnyOldName3 » 10 Jul 2020, 15:19

Shadow volumes are an evolutionary dead end and have no place in software created after 2010. That's why basically no software created after 2010 uses them, and the most famous game for having them came out in 2005. Their performance scales really badly as geometrical complexity increases, so they're not appropriate for full-quality modded meshes or full-scene shadows. They also can't do things like have a prenumbra, which is something you can clearly see in the real world (this isn't really something OpenMW does yet except in an abandoned branch, but there's nothing stopping it being added in the future). Finally, it's a nightmare to make them block light rather than just darken things uniformly.

I think most people are happier having shadows that are affected by more than just six objects, actually reflect what those objects look like, and generally behave more realistically than they would be with unrealistically sharp edges, ugly artefacts when things overlap, shadows jumping around when things move etc.
AnyOldName3, Master of Shadows

crowbarscientist
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Joined: 10 Jul 2020, 10:08

Re: Shadow volume?

Post by crowbarscientist » 10 Jul 2020, 15:40

A few game susing this technique has low poly models for the shadows. Grand Theft Auto: San Andreas uses the collision mesh for the shadows and Star Wars Battlefront 1/2 uses the LOD. So i don't think polycount would be a problem

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AnyOldName3
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Re: Shadow volume?

Post by AnyOldName3 » 10 Jul 2020, 16:43

Morrowind does that, too. It looks awful, though. The whole point of OpenMW is to not be awful.
AnyOldName3, Master of Shadows

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akortunov
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Joined: 13 Mar 2017, 13:49
Location: Samara, Russian Federation

Re: Shadow volume?

Post by akortunov » 11 Jul 2020, 10:41

crowbarscientist wrote:
10 Jul 2020, 15:40
Grand Theft Auto: San Andreas uses the collision mesh for the shadows
Not an option for OpenMW since most of Morrowind's meshes have a very rough collisions.

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AnyOldName3
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Re: Shadow volume?

Post by AnyOldName3 » 11 Jul 2020, 15:02

Actors have silhouette meshes, though.
AnyOldName3, Master of Shadows

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