hl2 bump mapping ?

[roader]

I saw a movie for about a year ago on hl2, the video was recorded on the map where you run from combines on rooftops.
Well in that movie the ceilings are very, very lifelike, all the ceilings have super realistic surfaces and the sun reflects on the celings. Well when I played this map it wasent half as good as on the movie. I have "full" on everything.

 

[NB.]

That was the HDR video, and yes the game does'nt look anywhere near as good. They might release a patch to enable HDR in future, but no-one knows.

The differences you are talking about have nothing to do with bumpmapping though.

 

[Kazuki_Fuse]

I disagree, from what I know, what he is referring to is specular highlights in that video that make the character and the ground an all that look shiny. HDR is only concerned with lighting.

 

[NB.]

Well the specular highlights are quite obviously still in the game, they are everywhere. The only thing that is different in the rooftop level in the retail game vs. the video, is the lack of HDR. Everything else is there.

Fire up the level and take a look at the roof tiles.

 

[fabianoag]

I disagree, from what I know, what he is referring to is specular highlights in that video that make the character and the ground an all that look shiny. HDR is only concerned with lighting.

No, NB is indeed correct. That wasn't a specular highlight on those roof tops in the tech demo, it was a HDRI.

 

[Aurek]

forgive me but what is HDR and HDRI?

 

[roader]

bumå mapping?

well then, what is bump mapping, thought it was how light reflects on diffrent surfaces and what is HDR ?
btw any news on when the "HDR patch" will be relaesed will make me very happy

 

[diluted]

What I'm upset about is that there isn't a giant antlion on the roof in the final game.

 

[roader]

maybe HDR is "high dynamic range rendering"? I know Gabe Newell says something about that in the video

 

[tuemmykids]

What I'm upset about is that there isn't a giant antlion on the roof in the final game.

I'm glad there isn't one, it would suck to fight it before you even get a crowbar.

 

[Brian Damage]

Okay...

Bumpmapping is where you take a kind of topographic map of a surface and apply it to a lit polygon to simulate extra surface detail. The sort in HL2, normal mapping, is a newer (in games), somewhat more complicated version which takes the orientation of the surface being simulated into account better.

HDR is where, in short, extra precision in internal colour calculations adds to the realism in colour gradients and helps in things like bloom more realistic. Good things that HDR does, I hear, are things like removing or lessening the banding sometimes present in textures, allowing for smooth colour graduation, and also reducing texture muddiness.

Specularity mapping is basically similar to bumpmapping, except you're mapping surface reflectivity instead of geometrical surface detail.

I recall that Gabe said something about the level of graphics shown in the antlion guard demo - which, by the way, was not a demo for Half Life 2, but a techdemo of the Source engine. I believe that perhaps that level of detail may be only available to the absolute highest-end systems.

Maybe in the ATI levels?

 

[roader]

whats "ATI levels" supposed to mean? Nvidia graphic cards TODAY rule the graphic cards that the developers used when creating the game.
I bet that Nvdia GeForce 6800 GT will be able to view that rooftop demo, since ATI never has been close to Nvidias graphic technics (in earlier days that is).

 

[roader]

to Brian Damage, isnt HDR much like a pixelshader then?

 

[The Dark Elf]

HDR - High Dynamic Range
- A method of rendering values deeper than the display device can show to allow the software to limit effects to a particular range (so with HDR a white wall will not have a bloom effect like a white sun will)

LDR - low dynamic range
- regular 255 RGB, white is white whatever it is supposed to be, a wall, a door, a sun, a flash of a camera. Applying bloom automatically to a LDR image will give a gaussian blur effect to the entire image, not limited to specific "invisibile" ranges

HDRI - High Dynamic Range Image
- a special type of image file that contains more values than is visible on a monitor but internally can be used to accurately light a scene. Common these days in pre-rendered artwork to get better lighting effects without using any real lights.

Bumpmaps or height maps
- grayscale images, where the value determins the height only. Black is low, white is high. Has no directional information, just height.

Normal maps / polybump etc.
- Uses RGB values to determin the direction of each pixel/polygon in an image. RGB, XYZ. Gives a better appearance as it knows which direction the light is coming from at each pixel in the image.

Parallax mapping / offset maps
- Uses a bumpmap image, grayscale. black is low, white is high. The engine/shader moves the pixels containing those values more or less depending on its value, giving a parallax effect to a surface.

 

[AJ Rimmer]

to Brian Damage, isnt HDR much like a pixelshader then?

Pixelshading is adding a shadow effect to behind a texture to create effects like water. Right? I had a test on this stuff a week ago and wanna now if I got it right.

 

[Asuka]

HDR - High Dynamic Range
- A method of rendering values deeper than the display device can show to allow the software to limit effects to a particular range (so with HDR a white wall will not have a bloom effect like a white sun will)

LDR - low dynamic range
- regular 255 RGB, white is white whatever it is supposed to be, a wall, a door, a sun, a flash of a camera. Applying bloom automatically to a LDR image will give a gaussian blur effect to the entire image, not limited to specific "invisibile" ranges

HDRI - High Dynamic Range Image
- a special type of image file that contains more values than is visible on a monitor but internally can be used to accurately light a scene. Common these days in pre-rendered artwork to get better lighting effects without using any real lights.

Bumpmaps or height maps
- grayscale images, where the value determins the height only. Black is low, white is high. Has no directional information, just height.

Normal maps / polybump etc.
- Uses RGB values to determin the direction of each pixel/polygon in an image. RGB, XYZ. Gives a better appearance as it knows which direction the light is coming from at each pixel in the image.

Parallax mapping / offset maps
- Uses a bumpmap image, grayscale. black is low, white is high. The engine/shader moves the pixels containing those values more or less depending on its value, giving a parallax effect to a surface.

Very interesting read. Didnt know some of that.

 

[Aurek]

Thanks for the HDR/HDRI explinations and the info about that video not being a Half-Life 2 trailer but a Source engine demo. Whats this about ATI levels any info/links to info?

 

[Brian Damage]

to Brian Damage, isnt HDR much like a pixelshader then?

Erm... I don't think so. As far as I'm aware, pixel shaders are part of the hardware pipeline of a graphics card. They help with shading calculations and perform special shader algorithms that give effects like HL2's groovy water. I'm not sure if they have any direct relation to HDR.

HDR - High Dynamic Range
- A method of rendering values deeper than the display device can show to allow the software to limit effects to a particular range (so with HDR a white wall will not have a bloom effect like a white sun will)

LDR - low dynamic range
- regular 255 RGB, white is white whatever it is supposed to be, a wall, a door, a sun, a flash of a camera. Applying bloom automatically to a LDR image will give a gaussian blur effect to the entire image, not limited to specific "invisibile" ranges

HDRI - High Dynamic Range Image
- a special type of image file that contains more values than is visible on a monitor but internally can be used to accurately light a scene. Common these days in pre-rendered artwork to get better lighting effects without using any real lights.

Bumpmaps or height maps
- grayscale images, where the value determins the height only. Black is low, white is high. Has no directional information, just height.

Normal maps / polybump etc.
- Uses RGB values to determin the direction of each pixel/polygon in an image. RGB, XYZ. Gives a better appearance as it knows which direction the light is coming from at each pixel in the image.

Parallax mapping / offset maps
- Uses a bumpmap image, grayscale. black is low, white is high. The engine/shader moves the pixels containing those values more or less depending on its value, giving a parallax effect to a surface.

Let's all hear it for HL2.net's Graphics Genius Man... Elf... whatever...

:cheers:

 

[PvtRyan]

Parallax mapping / offset maps
- Uses a bumpmap image, grayscale. black is low, white is high. The engine/shader moves the pixels containing those values more or less depending on its value, giving a parallax effect to a surface.

Correct me if I'm wrong, but doesn't parallax mapping work best when a height- AND normalmap is used? I thought a normalmap was a requirement for parallax mapping.

 

[Brian Damage]

Well, the way I understand it, the pallalax mapping used in that demo posted in one of these forums a while back is just an evolution of normal mapping that distorts the image slightly to enhance the impression of a 3D surface, so I'd assume it does use a normal map.

 

[Aurek]

Erm... I don't think so. As far as I'm aware, pixel shaders are part of the hardware pipeline of a graphics card. They help with shading calculations and perform special shader algorithms that give effects like HL2's groovy water. I'm not sure if they have any direct relation to HDR.

As far as I know shaders can be written by programmers in code somewhat resembling assembly. The instruction set is held on the card though so newer cards with newer instruction sets allow for better shaders.

 

[The Dark Elf]

Correct me if I'm wrong, but doesn't parallax mapping work best when a height- AND normalmap is used? I thought a normalmap was a requirement for parallax mapping.

You can DL little apps that show the parallax effect and strangely enough, in more than a few cases, the effect looks better _without_ normal maps being used.

You might be thinking of the faked parallax effect mod that was done for Doom3, the way he did it was strip one of the color channels from the shader to use as a parallax effect instead of being used for the normal mapping.

You can quite happily use normal maps though, But the height map is what gives it the parallax effect because its using the height information to, as Brian said, distort the image giving the impression of it moving at different speeds, depending on the "height" the grayscale map is giving.

Normal maps just continue to work as normal, so it can help the effect, but in some cases can make it look very CG compared to the more subtle parallax effect on its own.. Personal preference really. Trial and error to see what looks best, parallax with normal maps, or without.

 

[qckbeam]

Here is an excellent doc on parallax mapping:

http://www.infiscape.com/doc/parallax_mapping.pdf

Can't really put it any better than that.

 

[Brian Damage]

As far as I know shaders can be written by programmers in code somewhat resembling assembly. The instruction set is held on the card though so newer cards with newer instruction sets allow for better shaders.

Maybe TDE can clear this up, because as far as I'm concerned:

"Pixel Shaders" = The hardware on the card that handles the special pixel effects.

"Shaders" = The algorithms that tell the pixel shaders what to do.

 

[Aurek]

Thats what I meant, didnt make myself clear there at all.

 

[Brian Damage]

Well, we're in agreement then. Twice.