Tim Sweeney on UnrealEngine 3 shadowing

[Intel17]

Black font is my question, and blue font is Tim's reply;

Will Unreal Engine 3 have options to not just use the shadowing algorithms as they are stated on the website or is it so hardcoded that modders or licencees can't switch out different shadowing algorithms for different instances (e.g. moving light casting soft shadow-buffers on all objects in the scene rather than stencils)?



Designers have control over all of the shadowing options except for areas where it doesn't make sense (i.e. a dynamic object casting precomputed shadows).



So there you have it! UnrealEngine 3 can do all real-time soft-shadowmaps if the designer wanted, all real-time stencils or a mix of both!
UnrealEngine 3 is looking to be quite an engine, giving much control to the content creators and allowing for many types of games.

 

[suryad]

Sweet!

 

[Intel17]

I'm surprised not many people found this interesting, as it does answer the question Reverend had

 

[Ostsol]

They actually said something to this effect in one of the GDC videos and in a previous presentation as well. What may not have been clear was that designers will have such specific control over which shadowing technique will be used for a given object.

 

[Intel17]

They actually said something to this effect in one of the GDC videos and in a previous presentation as well. What may not have been clear was that designers will have such specific control over which shadowing technique will be used for a given object.

Actually, I don't recall them saying something to that effect, more like "physical objects cast dynamic shadows as you'd expect" .

What puzzles me though is why, on the website and from Daniel Vogel's comments on this site (and even Tim's response to Reverend), they kept saying that "x shadowing algorithm is used for x case".

 

[Ostsol]

They actually said something to this effect in one of the GDC videos and in a previous presentation as well. What may not have been clear was that designers will have such specific control over which shadowing technique will be used for a given object.

Actually, I don't recall them saying something to that effect, more like "physical objects cast dynamic shadows as you'd expect" .

The quote I'm refering to is something along the lines of "every part of the rendering pipeline is orthoganal and can be used in any combination." This was from one of the GDC videos. The speaker also said that the engine won't just have a set of features that work on static objects and another set that works on dynamic objects. Basically, the shadowing techniques' implementations are generalized such that none are specialized to a specific situation. Of course, an obvious exeption would be static, pre-computed lighting on dynamic objects.

What puzzles me though is why, on the website and from Daniel Vogel's comments on this site (and even Tim's response to Reverend), they kept saying that "x shadowing algorithm is used for x case".

He might have been refering to the defaults and Epic's own recommendations. It might even be just Epic's specific design decisions for their demos.

 

[Para]

They actually said something to this effect in one of the GDC videos and in a previous presentation as well. What may not have been clear was that designers will have such specific control over which shadowing technique will be used for a given object.

Actually, I don't recall them saying something to that effect, more like "physical objects cast dynamic shadows as you'd expect" .

What puzzles me though is why, on the website and from Daniel Vogel's comments on this site (and even Tim's response to Reverend), they kept saying that "x shadowing algorithm is used for x case".

One of the UE3 demo videos had a nice clip about faking an area light (shadow blurriness depends on the distance to light source) which of course is dynamic so this is kinda "old news".

 

[Intel17]

They actually said something to this effect in one of the GDC videos and in a previous presentation as well. What may not have been clear was that designers will have such specific control over which shadowing technique will be used for a given object.

Actually, I don't recall them saying something to that effect, more like "physical objects cast dynamic shadows as you'd expect" .

The quote I'm refering to is something along the lines of "every part of the rendering pipeline is orthoganal and can be used in any combination." This was from one of the GDC videos. The speaker also said that the engine won't just have a set of features that work on static objects and another set that works on dynamic objects. Basically, the shadowing techniques' implementations are generalized such that none are specialized to a specific situation. Of course, an obvious exeption would be static, pre-computed lighting on dynamic objects.

What puzzles me though is why, on the website and from Daniel Vogel's comments on this site (and even Tim's response to Reverend), they kept saying that "x shadowing algorithm is used for x case".

He might have been refering to the defaults and Epic's own recommendations. It might even be just Epic's specific design decisions for their demos.

Aha, I see. This actually makes for a better solution if they're trying to licence out technology. Epic gives us the option to go with a Doom 3 style shadowing game (albiet with much better shading etc...), we could also make a game which has all the same features and shadowing as JC's next renderer, a combination of both for a midpoint or even all pre-computed shadowing in a static world to make for a UT2004 type game.


I think this is quite an interesting topic...do you believe Epic's approach is a good approach to a game engine?

 

[Ostsol]

I think it is. Their primary interest in producing an engine appears to be to allow other companies to make games. It's a big difference as compared to designing an engine and toolset to be used internally for a specific game. Epic, by their own intentions, is forced to provide a rather broad featureset and SDK, which is better for everyone. In contrast, an engine made for a specific game is built around that game's potentially narrow set of requirements.

 

[Intel17]

I think it is. Their primary interest in producing an engine appears to be to allow other companies to make games. It's a big difference as compared to designing an engine and toolset to be used internally for a specific game. Epic, by their own intentions, is forced to provide a rather broad featureset and SDK, which is better for everyone. In contrast, an engine made for a specific game is built around that game's potentially narrow set of requirements.

I agree. Unreal Engine is extremely modular and the whole engine is designed for a multitude of game types, rather than just one genre or even one type of environment. The next gen Unreal Engine looks to be, truly the ultimate development platform, because the renderer is top notch, as well as the physics, sound, tools etc...

 

[RejZoR]

Remember, back in time they even made a 3D Pinball with Unreal engine

 

[Intel17]

Ostsol, tell me what you make of this other reply I got from Tim...

The completely general case of static and dynamic objects casting and receiving shadows from other static and dynamic objects is fully supported. But moving lights always cast stencil shadows from static geometry. We don't use shadow buffer soft-shadowing in that case; though it would be easy to do that. We already support cube map shadow buffers, but the performance and scalability of that technique for large-scale full scene shadowing is pretty questionable. Static soft shadowing precomputation is supported as an optimization and always behaves correctly interacts properly with other dynamic objects and dynamic lights in the scene (unlike, for example, Unreal Engine 2's entirely static shadowing.)

 

[Ostsol]

It somewhat contradicts the quote from your first post. Once again, though, it may just be a default setting. At worst, it's something that can only be changed by a licensee and it is not a setting exposed to modders. It's kinda hard to tell. Either way, the game developer still has the ability to use shadowing techniques in any combination.

 

[Intel17]

Notice the question in my first post, I specifically gave that example to Tim and then he replied. Ostsol, so in either case, would you consider Unreal Engine 3 to have the ability to do soft-shadows in real-time everywhere, even if it's not exposed to modders? Do you suppose a licencee would have to modify the renderer a bit to get it to work, or it's a matter of simply not giving modders the option (if the option isn't there, anyway)?

I would ask Tim for even futher clarification, but he has expressed annoyance in my frequent emails to him. Perhaps someone else would like to ask him?

 

[Reverend]

I would ask Tim for even futher clarification, but he has expressed annoyance in my frequent emails to him. Perhaps someone else would like to ask him?

<chuckle> Sorry OT : What did Tim say exactly to indicate his annoyance?

Actually, I'd thought of asking Tim a few questions about shadows and the kind of gameworld that most likely would exists in games using UE3 but I haven't had the time (tended to my old man a fair bit before he eventually went There) nor did I think Tim would be willing to tell me much about Epic's next game or about UE3 licensees' games.

 

[Ostsol]

Notice the question in my first post, I specifically gave that example to Tim and then he replied. Ostsol, so in either case, would you consider Unreal Engine 3 to have the ability to do soft-shadows in real-time everywhere, even if it's not exposed to modders? Do you suppose a licencee would have to modify the renderer a bit to get it to work, or it's a matter of simply not giving modders the option (if the option isn't there, anyway)?

Sorry, I was away for a couple days.

Anyway, as far as mod developers are concerned, the engine's support for soft-shadows is dependant on the game they are modding. However, I do consider the base engine package itself (that which licensees receive from Epic) to support full use of soft-shadows.

 

[Intel17]

Notice the question in my first post, I specifically gave that example to Tim and then he replied. Ostsol, so in either case, would you consider Unreal Engine 3 to have the ability to do soft-shadows in real-time everywhere, even if it's not exposed to modders? Do you suppose a licencee would have to modify the renderer a bit to get it to work, or it's a matter of simply not giving modders the option (if the option isn't there, anyway)?

Sorry, I was away for a couple days.

Anyway, as far as mod developers are concerned, the engine's support for soft-shadows is dependant on the game they are modding. However, I do consider the base engine package itself (that which licensees receive from Epic) to support full use of soft-shadows.

Are you reasonably sure about this? I quite hope your guess is correct!

 

[Ostsol]

I am definitely not sure. Based on what Tim Sweeney has said, however, it does seem the logical conclusion.