A general question about multi-texturing

[has981]

Hello forum,

My newbie qustion is: What is multi-texturing? is it possible in director? and where would I find a good tutorial about it and about other shockwave 3d issues?

[hondo3000]

the normal set up for a textured 3D model is:
from a modelresource you can make models, these models have shaders and the
shader brings the textures to the model.

in shockwave3D a shader will hold the settings how the textures are rendered,
how light effects them and so on. you can use in one shader up to 8 textures in
one shader. think of it as 8 layers in photoshop. you can now blend them in
different modes (additive, multiply, blend) and scale, rotate, translate them
independant from each other.
this is multitexturing (multipile textures in one shader)

UV cooridnates tell the shader which part of the texture belongs to a polygon.
in shockwave you can use one set of UV coordinates per model and you can use
different shaders on one model.

a good way to use multitextures is baking the light and shadows on a texture
and mix it with a "material" texture which is tiled. in this way you can have a
detailed and tiled texture under a large lightmap wich only makes the illusion
on light and shadows affecting the model.

you can use reflection-maps , alpha-channels and other things that are
possible with layering bitmaps on top of each other and blend and mix them
together. but you have to check if the graficcard support the amount of layers
you want to use. many card support only four of the eight possible layers. and
more layers, slower rendering. you have also a maximum of 8 lights, but for
good performance use not more then 2.

hope this is a little help to get started.

regards!

[has981]

Originally posted by: hondo3000
hope this is a little help to get started.


you kidding me!! this is HUGE help man, thank you so much, honestly.
of course other questions will follow but first I'm going to play around a bit
with it.

btwt, would you know of any good tutorial out there about this issue??

thanks again.

[has981]

HI there again hondo 3000 and all who can help.

I've been trying to do the following but with no avail.
I created a plane, converted it into a mish and created a terrain using a
grayscale image.
Now I have two image objects which I want to use in a shader for that plane.
I have called them img1 and img2 and i used them to create two textures tex1
and tex2.
tex1 will appear on the terrain as the default but in certain places (higher
places) I want tex2 to appear... of course there will be some place in between
where tex1 and tex2 overlap to produce a realistic effect.

To acheive this I used the 8-bit grayscale image ( the one I used as a hight
map) I used it as the alpha channel of img2 of tex2.

so I added tex1 to my shader then added tex2 to my shader and now what happens
is that the area of the terrain where tex2 is required is the only area that
appears and the rest is absolute darkness ( it graduates from apace to
transparent according to the alpha channel).

I tried to manipulate the shader with the blendFunctionList settings (using
3dpi) but I still do not get the right effect.

PS. the renderer format for the textures is set to rgba8888.

Any help would be higly appreciated.
Thnx again.