Displacement shadow mapping

adam · Aug 2005

Anyone have links on this? Or how its created? I read about it in the Project Offset tech dossier and was hoping there's some other documention on it.

I'd like to experiment with it.

MoP · Aug 2005

Deforming shadows based on the normal-map of a surface? From the looks of things on their site, it's a new technology only they're using.

adam · Aug 2005

EarthQuake was mentioning that parallax/relief mapping does this. What do you think MoP?

MoP · Aug 2005

From the examples I've seen, relief mapping definitely does that. Although I don't know if you could get any engine or shaders that could do that yet.

AFAIK parallax mapping doesn't modify shadows cast on the surface (although i guess that depends if the shadow is calculated before the shader shifts the co-ordinates), but Ben Cloward has a DX9 shader on his site which does parallax mapping. No shadows in real time in the Max viewport though.

adam · Aug 2005

I thought relief mapping was more for shifting virtual geometry (created by the normal) and adding in perspective to make it seem even more 3D - thus making the shadows moving a bi-product of the effect?

It sounds more like "displacement shadow mapping" is geared towards the shadow tech specifically.

Guess I'll have to wait.

Keg · Aug 2005

Maybe email the guys at project offset concerning it?

adam · Aug 2005

Good suggestion, I'll give it a go!

StrangeFate · Aug 2005

[ QUOTE ]
Deforming shadows based on the normal-map of a surface? From the looks of things on their site, it's a new technology only they're using.

[/ QUOTE ]
Nah, it's not new. I think it was just not worth an extra pass or something... can't remember, old stuff

lio · Aug 2005

I´m not sure about technical terms - not even if this is close to what Project Offset does or how it´s done in this demo but it looks pretty cool imo:

http://www.humus.ca/index.php?page=3D&ID=38

Kevin Albers · Aug 2005

I've worked on a game before that used self-shadowing parallax displacement...it's a very nice looking effect. It was easy to implement as an artist. You simply use a bump/height map plus a normal map. I assume that lots of game engines will soon feature self-shadowing displacement. mmmm.

adam · Aug 2005

I sent an e-mail to the Project Offset team about this. I'll post what I get back.

PaK · Aug 2005

The way offset/parallax mapping works is it displaces the UV co-ordinates to simulate parallax.

In this photoshop drawing:

-the green lines represent the effect of the color map (traditional texture)

-the shaded middle bit in the center is the effect of the normal map.

In the image to the far left you can see the green lines bend in perspective along with the normal maps bump.

In the image to the right you can see that the green lines do not bend with the normal map.

The parallax map allows an image top distory properly in perspective in relation to the normal map.

If you have played f.e.ar. then you have seen parallax maps in action. pay particular attention to their bricks, they have been parallax mapped beautifully

I will have a huge tutorial on all this stuff along with all my normal mapping tricks and photoshop swatches/actions and goodies I have compiled to go along with it

....and maybe some of the scripts i am writing for max (I'll have to ask my boss about that one, im sure he'll say no) the moment someone releases a parallax map capable toolset for the public, like monolith.

-R

EarthQuake · Aug 2005

Relief mapping will get you shadows as will STEEP parrallax.
http://graphics.cs.brown.edu/games/SteepParallax/

Its "new" in the sense that it hasnt been used in a released game. But the tech is about a year old.

Displacement shadow mapping

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