atomic bomb tutorial en

Simplified tutorial: Massive explosion - Blender

Fweibel.com 1/12 ©2008 Fweibel

Atomic bomb with Blender!

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Introduction This article was created for people who are interested in creating virtual special

effects with blender.

This is the 2nd tutorial I wrote about this subject. This one has been simplified.

Anyway, it requires some basis with blender…

Global method This technique I developed to simulate a massive explosion mainly uses the

displace modifier:

Raw meshes objects (without displacement)

Meshes objects (with displacement and subsurf level 4)

Fireball

ColumnTop

Column

Shockwave



Massive explosion smoke dynamics

This picture shows the global dynamic of gazes produced by nuclear fission:

Warm burning gases rises and cool down with the altitude, which creates this

rolling effect on the fireball

To simulate this, we’ll use 3 empty’s which will be uses for displaced texture’s

coords.

« Empty’s » for texture’s animations

Adjust their size to obtain the best looking result when the modifiers have been

added (see below)

« Up »

« Fix »

« Down »



IPOs: « Up » « Down »

Textures used for displacement

“Displ 1”

Large noise, this texture will be used to change the global aspect of each

mesh objects.

“Displ 2”

“Displ 3”

Small noise, for more details…



Meshes: Shockwave

Animation

IPO keys (scale): Frame 100 : X,Y,Z = 0.0

Frame 500 : X, Y = 2.0 ; Z = 1.5

Modifiers

The shape of the curves are important, it

will give the damping effect : Quick

growth at the begining, then slowing

down

Note : Shockwave grew less in height

than in width

1st deformation level:

Make the global shape of the object

changes

2nd deformation level:

More detailed. I used vertex groups to

randomize the displacement level over

the object’s surface.

3rd deformation level:

Also use of vertex groups

Subsurf : Here you can change the level

of details.

High values will increase the render time



Mesh : Column

Animation

IPO keys (scale) : Frame 100 : X,Y,Z = 0.0

Frame 500 : X,Y,Z = 1.2

Modifiers

This will give the sensation that hot gases

are rising up…

Curve of Z axis is different. You’ll need to

adjust it depending of the rising speed

of the fireball object



Mesh : ColumnTop

Animation

IPO keys (scale) : Frame 100 : X,Y,Z = 0.0

Frame 500 : X,Y,Z = 1.5

IPO keys (loc) : Frame 100 : Z = 0.0

Frame 500 : Z= 10.0

Modifiers

Z loc, to make the object rising



Mesh : Fireball

Animation

IPO keys (scale) : Same than the previous object

IPO keys (loc) : Same than the previous object

Modifiers

Important : For the « rolling » gases effect

Same IPO block than the ColumnTop

object



Materials :

Here we are going to see how to create the burning in the core of the fireball.

For this we’ll use 4 times ONE texture which will react to the lighting of 4 lamps.

Each texture will be linked to one lamp.

Creating the 4 lamps

Add 4 lamps (renamed to “FireBallL 1,2,3,4”) and linked them to the object

fireball (parent)

Lamp settings:

Place the lamps randomly in the

fireball.



Material

It will be used for shockwave, column, columnTop and fireball (actually, every

objects…)

Texture

Assign 4 times this texture to the material (in 4 different channels)

Every texture will have a linked lamp :

Tex in channel 1: FIreBallL1, Tex in channel 1: FireBallL2, Tex in channel 1:

FireBallL3, Tex in channel 1: FireBallL4

Activate « Emit » and « TransLu ».

Add an IPO curve for th lamp’s power

(combustion attenuates)



Halos First, put the 3d cursor on the fireball. Then add 4 spots.

For each one, add a constraint “track to”, to direct them to the active

camera:

The glare comes mainly from the fireball, this is why the spots must be parented

to the object “fireball”.

Spots settings

Add an IPO curve the control the spot size (for the attenuation)



Conclusion Thanks for following this tutorial! I hope it was useful.

Visit my web site http://www.fweibel.com

My youtube channel: http://www.youtube.com/faweil

atomic bomb tutorial en

Technology

simplified tutorial

details fweibel

com1122008 fweibel

com4122008 fweibel

vertex groups fweibel

rolling gases effect

fireball object modifiers

ipo curve