Great amount of questions, help very appreciated

Snickel · Post by **Snickel** » Fri Feb 03, 2006 7:41 pm

Hello, I'm from artist's background but learning programming extensively for half a year(I already knew some basic C++ before that).
slowly learning OpenGL and DirectX, but my aim is not to become a engine programmer
so I already had glimpse at Irrlicht, and I found it jolly nice.
I actually need to know what of described below is pretty much already
provided in free(as in...) graphics engines(beautiful Irrlicht or OGRE) and which of the
steps in order to make them I need to better learn OpenGL and/or DirectX apis.
I would appreciate if you explain me each and every point.
This should definitely make my learning more efficient.Thanks.

This is my prime goals:

Reflection:

Step 1 Having cube(or sphere, although it looks ugly) enviroment texture simultaneously with bitmap texture applied to one mesh.
Desc.: What I mean by `texture' is it should be loaded image file, in this case a env map(four files for each direction or one combined)
and one simple image file for diffuse map. And of course I should be able to set transparency for env texture. I pretty unsure but
probably it would be way better to have each map use a different UV projections(So far I didn't find any exporter who would support this, so I should probably learn MAXscript, but then I'll need to make an importer too :/)

Step 2 Same as above plus alpha texture for env map.
Desc.: grayscale image file(s). if it's too complex maybe just black and white for `show, not show', I dunno.

Bump and normal map:

Step 1 normal map on animated mesh.
Desc.: `normal map' I mean NOT a grayscale image, but a coloured image with already calculated smooth heights(i.e in 3dsmax).
I don't know much about this yet, so clarification from your side will be much anticipated.

(petty fantasy)Step 2 same as above plus env map.
I think Half-life 2 has it? applied to a water? probably just some shader but not an animated mesh, right? I can't check because my gx card pretty damn old
so ain't showing it, but I saw screenshots.

(petty fantasy)Step 3 animated(NOT a moving UV mapping as in DirectX example, but actual different image files) normal map.
Desc.: not animated really, but 2-4 changing textures would bring MUCH realism I think(i.e. cloth folding, facial wrinkles.)
I concerned about this coz I never saw it in any game(which is surprising), and I don't think it's heavy on CPU or GPU consuming(I'm wrong?)
so what's the problem here? Am I dreaming already?

Snickel · Post by **Snickel** » Sat Feb 04, 2006 12:21 pm

*bump*
eh? no one cares to help me?

Well let's try again then, plus I have
additional question.

What exactly clears the screen in Irrlicht?
beginScene() or endScene() ?
I mean how to NOT clear screen every frame?
To create something like in Doom(1,2) then you disable clipping and go out of world boundaries.

dhenton9000 · Post by **dhenton9000** » Sat Feb 04, 2006 2:59 pm

Snickel wrote:*bump*
eh? no one cares to help me?

Well let's try again then, plus I have
additional question.

What exactly clears the screen in Irrlicht?
beginScene() or endScene() ?
I mean how to NOT clear screen every frame?
To create something like in Doom(1,2) then you disable clipping and go out of world boundaries.

I'd love to help but I don't know half the answers. If I had to answer these for my life, I'd go run each of the samples in the Irrlicht SDK (esp the one called Special Effects) and see if what you are looking for are in those demos. Niko's demo's cover just about every out of the box capability.

As for clearing the screen, the beginScene and endScene of Irrlicht correspond to opengl begin and end (especially if you select the opengl driver!) I think most screen clearing is done on the first. Not clearing the frame sounds like Render to Texture, perhaps?

BTW, the Forum police will get you for bumping the thread

luckymutt · Post by **luckymutt** » Sat Feb 04, 2006 5:58 pm

dhenton9000 wrote:BTW, the Forum police will get you for bumping the thread

Na...he let a day go by...besides, afecilis is out of town

@Snickel - I don't quite follow you on what you are trying to accomplish with the "reflection" - are talking about putting a diffuse map on top of the env map? And approaching the enviremoent as a mesh?

Guest · Post by **Guest** » Sat Feb 04, 2006 8:59 pm

dhenton9000 wrote: @Snickel - I don't quite follow you on what you are trying to accomplish with the "reflection" - are talking about putting a diffuse map on top of the env map? And approaching the enviremoent as a mesh?

Nah, simple `cube env', with ``specular map''(or how to call that? different
packages tend to call that differently) embeded in `diffuse map' as alpha channel.

please note that I call ``diffuse'' as in 3dsmax jargon.

so basically after `step 2'(why did I invent those stupid `steps' right, just brings confusion, heh)
I should be able make following example

so example:
1) some mesh
2) diffuse - color image file with alpha channel //alpha channel for env
3) env - color image file
4) Profit!

this is how it's done half-life2, heh.
In real-life™ things tend to be more complicated.

So can this be accomplished in Irrlicht now?
if not, what can I do to make it happen?
i.e. maybe beg some superior members in these forums to make it for me,(yeah...I can do that...just name them..)

or the only alternative,
again is the hard one - `learn and make yourself' :0(