Global Illumination

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Del curso dictado por University of London

3D Models for Virtual Reality

83 calificaciones

University of London

3D Models for Virtual Reality

83 calificaciones

Curso 2 de 5 en SpecializationVirtual Reality

This course will begin your journey to creating Virtual Reality experiences. A Virtual Reality experience is a new world that you step into and are entirely immersed in. Creating a VR experience means creating that world and all the objects in it. In this course you will learn the basics of 3D graphics: how we create objects and how to lay them out to create an environment. You will learn techniques like materials and texturing that make your objects appear realistic. You will also learn about audio techniques to ensure that your experiences sound great as well as looking great. In all of these topics we will pay attention to the particular requirements of Virtual Reality, including pitfalls and performance issues: making sure your environment runs fast enough in VR. You will learn all of this using the professional game and VR engine, Unity3D. Unity is one of the most used game engine and is a relatively easy, but fully featured, introduction to 3D development. The course will culminate in a project in which you will create your own VR scene. VR development is something you can only learn by doing it yourself, so working on your project will be the best way to learn.

De la lección

Content Creation: What works in VR?

In this final week of the course, we will put together everything we have learned to think about how to create compelling VR worlds. We will start by looking behind the scenes at how 3D graphics hardware works and why VR can be so demanding of computing power. Then we will think about the particular requirements of content creation for VR. You will finish by submitting the final version of your project for a peer review.

Introduction to Week 41:06

Polygons to Pixels4:20

Motion to Photon2:32

Global Illumination4:25

Conoce a los instructores

Dr Sylvia Xueni Pan
Lecturer, Department of Computing
Goldsmiths, University of London
Dr Marco Gillies
Senior Lecturer
Computing Department, Goldsmiths, University of London

[MUSIC]

Computer graphics lighting web presents the kind of lights

we have in the real world.

You have objects and lights.

And lights bounce off objects and arrive at the camera.

And when they arrive at the camera, that's when they make an image.

But actually, most of the light

in our environment doesn't come directly from the lights in that way.

If all the light came just from the lights,

then anything which wasn't directly facing the light would have been incredibly dark.

You get very, very stark lighting.

Everything would need to be really bright or really dark.

Actually in the real world, a lot of light goes from our light source and

bounces off the walls before hitting objects and reaching the camera.

So actually we have a lot of light bouncing around.

And so real world lighting is much less stark and

much softer than we get with straight computer graphics.

And simulating this kind of

bouncing around light is called global illumination.

And if you compare it to the standard direct illumination which is on the left,

global illumination on the right looks much nicer, looks much more realistic.

And the light's much softer, and you get nicer shadows and nicer reflections.

The trouble is it's a lot slower because we have to instead of just

simulating one light path from the light to the object to the camera.

We have to simulate lots of bounces of rays of light all over the place.

So though global illumination looks really great,

it can be a little bit too expensive now.

Though with modern hardware,

you're seeing platforms like Unity include global illumination.

So it's certainly something you can look at with the latest

Unity renderers is turning on global illumination.

But you have to be aware that VR is very computer intensive,

so it may slow things down too much.

So you can use for global illumination or approximations to it in platforms

like Unity, but I wanted to mention two basic little hacks.

The first one is built into everything, it's called ambient light.

Basically, as well as the lighting coming from light sources,

you just add light coming from everywhere.

Every object is just lit up by a little bit of light that comes in all directions.

It's not very realistic.

It doesn't create that soft lighting we like, but it's very fast and cheap.

So any basic renderer will include ambient lighting, and

you can set that on your Unity project.

The other hack is a bit more complex.

What happens is you do global illumination.

But you don't do it at one time while you're running your game or

your VM environment.

You do it beforehand while you're developing it.

And what happens is you

render all that high quality global illumination to an image.

Well, actually texture that could be applied back to the object.

So you're doing the high quality illumination and

creating a texture that you just text your map onto the object.

But it makes the object look as if it's rendered really nicely.

Doesn't really work if the object's moving around loads or

the lights are moving around loads.

But it's a cheap way of creating really high quality looking illumination,

at least for static environments like rooms and furniture.

So that's something I'd recommend, and Unity can do that for you.

So global illumination is one example of a really powerful

modern graphics technique that can make things look really, really good.

And you should basically look at some of those techniques if you want

to have a VR experience that looks really real.

[MUSIC]

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