DFMOD MD3 Skinning/Texturing Tutorial

• Paint Shop Pro for the drawings
• MD3View to preview the textures on the model
• ShaderEd to edit and preview the shader
• Q3ASE to preview the shader on the model

The model used in this tutorial was done for the DFMOD, a conversion of the good
old DOS game Dark Forces for Jedi Knight - Jedi Outcast.
All models and textures are beeing recreated to look like or at least very similar to the original drawings.

The actual model represents a revive item and was an animated sprite (flat object) in DF:



DF revive	enlarged view


The model has basically two parts:
- a gray, perhaps metallic housing
- an red-orange-yellowish pulsing light emitting device that looks like some kind of crystal

The creation of the MD3 model will not be discussed here.
We'll assume you have it already, it may look like this in the modeller:



3D model of the revive item in editor

Before drawing the texture, the 3D model must be converted into a flat form
also called UV map, where all the polygons that have to be textured are visible.

Because the originally flat texture is wrapped around the 3D model
by the 3D engine it will look ugly if the texture is not designed and painted carefully!

Here is the UV map and how it looks on the 3D model.
Some tools allow to extract the UV map with shades of colors
so the different polygons can be distinguished more easly.
You can also paint yourself the polygons in order to locate them on the model.



UV map	UV map with colors	UV map with 4 colors


With the revive model the UV map is relatively simple to decipher.
The upper rectangle represents the crystal part and the lower shapes represent
different sides of the base housing.



UV map	UV map with colors	UV map with 4 colors

Hint: Create a new raster layer for each step. Separate modifications can be made more easily then.

Hint: In PSP 7.x use the vector elements, they can even more easly be modified than raster images
and filled with solid colors, gradients and patterns with one click.

Remember: you can later always convert a vector layer to a raster layer,
but you can never convert a raster image back to a vector layer!!!

The crystal like shape is very easy to draw.
Draw and fill the top side (lower square) with orange color and the sides (long rectangle above)
with a gradient from orange to dark orange or red.

In the following picture I reduced the opacity of the crystal texture with the slider on the layer palette to show the polygons behind:

And here the resulting skin and how it looks on the model:



Crystal texture	Crystal skin 3D view

The base is made of 3 different polygon shapes:
- the cube inside
- the 4 fingers outside
- the inside of the fingers

The cube and the inside can be drawed darker, but the outside of the fingers will be lit.
I choose gray shades, filled in different directions depending on the orientation of each polygon on the model.
Since the right polygon shape is symmetric it does not need to be painted strictly following the edges.
You can do that, but using a shaded square here was much easier.
On the other hand, the shade does not exactly fit the side polygons, but the color difference is not that important here.




Skin	3D view


This looks already quite good, but it is too flat and too clean also.

Now the base housing will be modified using different effects.
First duplicate the previous layer to preserve the original grayscale texture.

Then use the Retouch tool with Darken RGB effect, but at reduced density to get lots of spots:


Retouch with Darken RGB

For an interesting effect, you now could apply the Median filter located in the Effects -> Noise menu.
Then the surface will look a bit like brushed metal, the sharp spots will be erased,
but without the typical reflections it rather looks like beton :)

If you can't see a difference between the image above and the one below, then it is due to the JPEG compression, it also uses filters to reduce the file size...


Median filter effect

Hint: Always watch the layer you are currently working on, it is highlighted in the layer toolbox.
Although you can undo all previous actions, you don't see wrong actions while drawing onto a layer
that lies under a completely opaque (= not transparent) layer.
If you are unsure, just stay with the mouse over a layer's name and it content will appear in a small window.
Or simply switch off temporarily all unused layers.


3D view of the Modified base texture

The result is a bit better so far, but there still could be more shadows,
and the light of the crystal is not beeing reflected by the side parts.

You now may think this all could be realized with shaders.
Sure, but this would eat up lot of performance if every single object
or item would use several shaders to generate the different effects.
We'll use one only shader for the light emitting effect later.

Simply fake because we now will draw them right into the texture...
So please duplicate or do a Edit...Copy Merged and Edit...Paste...As New Layer of the previous layer again.


Shadows and reflected light

The shadows were added with the Retouch tool using Darken RGB, but this time at 100% density.
Please take care not to move the mouse while applying the Darken effect else it will make very dark strokes.

The light effect is restricted to the top of the base cube.
First draw a circle with orange-red gradient,
then apply the Retouch tool with Color to Target effect
at 50% density to lighten the edges of the top side a bit.

The inside part of the fingers can be drawn in a darker orange-red
or brown color to simulate some light reflection also.
The upper half can be darker since it will not get much light of the crystal.


3D view with fake lights and shadows

Now this looks very finished and nearly realistic!
Take into account the item will not be very large in the game since it is a small thing.
So little imperfections are not visible unless the player looks at it using goggles :)

Before using a shader, we have make a glow texture.
The glow texture is the texture that is beeing used to emit light only at defined places of the model.
If you would just use the texture we created until now, the item would not be visible in the dark,
and if you would use that as glow texture the whole item would glow...

Basically the glow texture could just contains the zones restricted to the exact lighting parts.
Adding some blur adds a nice halo to ny kind of buttons and switched.

Now duplicate the layer that contains the basic orange shades of the crystal shape.
Add an orange-red shaded rectangle for the inside of the finger and again a shaded circle
for the top of the cube.
Then use the Gaussian Blur effect with a radius of 4.0 to add the halo.

You'll notice I have added two dark yellow strokes on the fingers,
they are for the reflection on both sides!


Special layer for the glow texture



Semi transparent glow to see the polygon borders	3D view (normal texture + glow)


This now looks pretty cool, but that's only to see if the glows are correct.
The real light finally comes now...

Just to see the differences between the steps, I put all the skins and 3D views in a line:



Crystal and polygons	Basic texture	Darkened & filtered	Fake lights & shadows	With glow texture

To have the crystal litterally emit light, you'll have to write a shader.
A shader is a smaller program that e.g. tells the engine how to deal with textures and to apply them on models.

For the revive item we just need a light effect.

You can use ShaderEd, Q3ASE or just notepad to create the file.



---

skin_tut
{
  {
     map skin_tut.tga
  }
  {
     map skin_tut_glow.tga
     blendfunc add
     rgbGen wave triangle 0 1 0 0.5
  }
}

---


The first entry is the name of the model, then the normal texture and finally the glow texture with the actual shader effect.
The blend function simply adds the values of the glow texture to them of the normal textures,
this produces some overbrightness and finally looks like light emission.


Settings in ShaderEd

I've added a wave generator to let the light fade in and out slowly - with a period of 2s.

Using Q3ASE you even can preview the shader on the 3D models:



Q3ASE	Light glow with shader


And finally the whole thing animated:


Shader lighting animated

The last thing to do is to use the model, the texture and the glow texture, and the shader in the level,
but how to do this has already been discussed in other tutorials.

Here is the tutorial file for use with Paint Shop Pro version >6.x.
It contains all the layers presented above.