Fly a Fighter Aircraft Through a Storm - Blender 2.5 - page 90

Classified Intel
Volumetric materials are special because the simpliicaions applied to develop the standard
shading models only apply for objects with a deined surface. Given this situaion, there was
a need to develop techniques to render volumetric materials in CG, and thankfully, we now
have such an implementaion available in Blender.
The main reason for volumetric materials being much more heavy to render than a standard
material is that the renderer must simulate the actual process of light traveling inside the
volume, and its scatering inside and outside, taking into account the variaions in density,
scatering, and so on. Common surface materials are rendered much faster because the
renderer only needs to calculate the interacion of light with the surface.
Assembling the Final Scene
With all the pieces ready, it's now ime for us to link all the objects to a single scene, and
set up the final elements for render. Since we have all the objects in the same Blender file,
geing them into the same scene will be very easy.
Engage Thrusters
1. Start by creaing a new scene and naming it main .
2. Then go to the fighter scene, select both the fighterBody and the fighterStabilators
objects, and go to Object → Make Links... → Objects to Scene... → main .
3. Now go to the env scene, select both the cloudShape and the giant cube objects
and perform the same acion to link them into the main scene. Next, go to the
main scene.
Comparing the relaive sizes of the cloud and the aircrat, it is clear that they are
not correct.
4. To fix this, let's create a new Empty object ( Add → Empty ), clear its locaion ( Object
→ Clear → Location ), and its rotaion ( Object → Clear → Rotation ).
5. Then make sure that the fighterBody object is located at the center of the 3D World,
select both this and the fighterStabilators object, and then select the recently
created Empty object, now parent the objects to the Empty object by going to
Object → Parent → Set .
6. Name the empty object fighterParent and set its scale to 0.3 .