Bitmap option

[AJ]

I asked this in "Tech" but nobody answered. I know I'm stupid but can anyone tell me what the "Bitmap" option is for in the Main Histwar Entry Room.  What does it do and what advantages or disadvantages are there in selecting this option?

[LNDavout]

Hmm do you mean the bumpmapping or the AVI option ?

[AJ]

Sorry, "Bumpmapping" is correct.  Still, I haven't got any answers

[Hook]

Sorry, "Bumpmapping" is correct.  Still, I haven't got any answers

I thought I did answer:

Bump mapping is supposed to add additional texture shaping to the troops, but I haven't noticed any difference with it on or off.  Maybe that's not what it actually does

Try it on and off and examine the troops closely.  See if they don't look like the uniforms have more shape to them, like the belts across their chests and things.

Hook

[Regiment 0]

Bumpmapping is a way to add extra detail to a 3D model without adding extra geometry. The game's rendering engine applies bump maps when this option is on, which should give more depth to the models (e.g., a shoulder strap might look like it is raised slightly).

For the technical, however, I think HWG uses normal maps rather than bump maps.

[Hook]

For the technical, however, I think HWG uses normal maps rather than bump maps.

The bump map graphics are there, but I don't know if they're used, or if the setting does anything.

Hook

[Regiment 0]

It's been a while unfortunately, but I think there is a very subtle effect - perhaps it is most noticeable on the buildings - but you have to zoom in close.

(As far as the maps go, I seem to remember them being normal maps (they are coloured in shades of blue, green and red) rather than bump maps (which are just greyscale), but I could be mistaken. Which is used makes no real difference to an end user, so I don't want to get this off-topic. We'll have to wait for JMM to release his modding info before we can get into the nitty-gritty.)

[AJ]

Sorry Hook, I must have missed your answer, I just hit "Unread Posts" whenever I log on and I must have missed it.
Thanks to you all for your explanations, I'll try it.

[Wellesley]

Bump map is a form texture that add some undulation to the surface in addition to normal colour flat texture.
These 'bumps' slightly perturb the normals to different points on the surface so that light is reflected off in a more
realistic fashion that a completely flat surface.

Welly

[TC237]

I'm going to throw my explanation into the ring 
Bump Mapping is a technique used to give a 2d image a 3d effect via the manipulation of the light source.

Polygons, Textures and BumpMapping.

HW's soldiers, horses, equipment, buildings are 3d models made up of hundreds of Polygons.
Every flat surface on that model is made of at least 2 Polygons.
The more Polygons on the model the more computing power needed to display it on the screen.
If the 3d model includes many small details like buttons, straps, ears, nose, windows, doors, etc...
it will have thousands of polygons, per each 3d model, for the CPU/GPU to process.
A game programmer and artist try to get the best looking game for the least amount of CPU/GPU usage.
They try to use the minimal amount of Polygons on the 3d models as possible.

A Texture is the uniform or  "paint" on a 3d model. It is a graphic file that the game engine drapes over the 3d model.
A Texture is flat (2d) and has no 3d elements. The artist can use visual tricks with highlights and shading to give the Texture a faux 3d effect.
(look at the buttons on your OS or internet browser, there are many examples of using shading and highlights to make a 3d effect)

A Bump Map is a method used by artists to create a 3d effect using 2d Textures.
An exact duplicate of the Texture is adjusted so that the color is removed, the "light source" in the image is adjusted so that the shadows and highlights remaining give the image an "embossed" effect. The high points appear raised above the surface of the image. (like the numbers on a credit card)

If this "embossed" Bump Map is place under the flat Texture, it gives the Texture a subtle 3d effect.
Place a credit card under a flat sheet of paper and rub on the paper, you will get a 3d "embossed" effect on the paper.

Bump Mapping is a "cheap" way to get a 3d effect on a Texture (3d model) without actually using more polygons in the 3d model itself.
The artist can get those small details on the 3d Model without increasing CPU/GPU load.

The downside to using the BumpMapping option in HW is that the game loads a second Texture file for everymodel.
If you have a decent GPU with enough memory there should be no problem.

...something like that...

[glaude1955]

Thank you for explanations TC237, (as well as to the another one)

A+ 
Yves