How to transform smoothly one object in to explosion?

[ISUther]

Hello, 

I have a object that animates (take a look at project file)
I need that object smoothly transform in to explosion from specific frame.
How to do that?
 

Spider.Project.Molekul.hip

[catchyid]

Hi,

I am not I understand the question entirely, but I guess one of the things you need to do is to pre-fracture your geometry to allow for the explosion. Would you be using Dynamic simulation for that?

[Atom]

You could try the shelf tool.

Select your SPIDER object and click the Explosion icon under the PyroFX shelf.

Wait for the networks to be generated then dive inside the pyro_sim node.

Select the source_fuel_from_SPIDER node and place this expression in the Activation field.

if($SF >96, 1,0)

 

This will cause the explosion to be generated from the current shape of the SPIDER object starting at frame 96. The flame will continue to grow from that time.

That will get the flame started in the shape of the object, your next step would be how to transition the existing SPIDER object off the screen. I'm not sure what you have in mind for that? (fade, particle dissolve, fracture...etc.)

Edited September 9, 2016 by Atom

[vtrvtr]

11 minutes ago, Atom said:

You could try the shelf tool.

Select your SPIDER object and click the Explosion icon under the PyroFX shelf.

Wait for the networks to be generated then dive inside the pyro_sim node.

Select the source_fuel_from_SPIDER node and place this expression in the Activation field.

if($SF >96, 1,0)

 

This will cause the explosion to be generated from the current shape of the SPIDER object starting at frame 96. The flame will continue to grow from that time.

That will get the flame started in the shape of the object, your next step would be how to transition the existing SPIDER object off the screen. I'm not sure what you have in mind for that? (fade, particle dissolve, fracture...etc.)

Unrelated question but what's the difference between using that expression and just "$SF > 96"? 

[Atom]

In this case, they are the same thing, a boolean response. But by explicitly declaring the else value you can drive more than Activation fields, for instance particles counts. if($SF >24, 100, 200). I guess it is an old habit from programming to specify the else.

[ISUther]

Hello, 

Thank you for the answer. 

I tested out the explosion tool separately used spear but that does not seem to make explosion come from the spear it turns spear in to start of explosion already. 
I needed to do it smoothly
Idea was that i have animated object (in this case that spider) and it then will explode and create powerful explosion. 
I wanted to do something before explosion. So it has some kind of story behind it. 
I know i am beginner but skill is achieved through practice and hours and hours trying to do it .
But at the moment the "story" what i have is too short and boring. I wanted that this object that u see in video moves and one point starts to dissolve as those particles and evolves in to the explosion (and it should look like explosion is coming from that object particles)

What i don`t know how to do is how to make it smooth (evolving or changing from one object to another. In this case explosion).
As  when i select object and click shelf tool it instantly turns that in to smokey thing from what explosion starts  but that is not my goal as i need it to be smooth.
(Particles that u see in this animation are created after i rendered out tif sequence for animation in Houdini and imported those in to Adobe After Effects where i used trap code particles) 
At the moment going to check and search houdini 15 particles may be those are better and i do not need to do trap code particle stuff in adobe. 
And thank you again for everyone trying to help me. Not many communities out there who are this helpful. 
Here is my animation at the moment. 

 

[Atom]

I put together a video a while back on how to morph fonts between phrases using the isooffset node. Even though the example is font based there is no reason why you can't substitute other geometry shapes instead. You could setup a morph between your spear and the spider sphere then apply the explosion on top.

Here is the video:

 

I am also attaching the final HIP file from the tutorial as well.

ap_pull_the_beat_back_morph_ts_blend_SDF.hipnc

Edited September 12, 2016 by Atom

[ISUther]

Ok thank you!
I will try this, but few questions: 
1.) As i understand instead creating Font node i need to create Geometry node? And dive inside Geo Node and delete whatever it created there and instead import in Spider? (effect that i have)
 2.) Or i need to dive inside Spider node and create there but instead font create sphere? 
3.) As i understand i need also to create copy of spider node and apply to that one Explosion from Shelf tools, but that creates 1 more node in to Scene level 
Should i import somehow that pyro to spider effect?
 

[Atom]

Use an ObjectMerge for each object to bring in both the sphere and the spear. Remember to change the drop down in the ObjectMerge to "Into This Object". This way your two source geometries remain as they are. The morph geometry, which is importing both of the merged geometries, is what you would apply the explosion to. So in the scene you would end up with 3 geometries, the sphere, the spear and the morph. Turn off the render flags on the source sphere and spear. So in the end you really only have one object to deal with, the morph object.

[ISUther]

I am dooing something wrong. 
Here is my hip file if you can and have time can you take a look at it and have any clue what is wrong?
I thi nbk something is wrong the way i import those objects (pyro and stuff) in to object merge nodes,

Spider.Project.Molekul.question.hip

[Atom]

Yeah, that looks kind of wrong. The IsoOffset accepts geometry. You're just routing pyro stuff right in there assuming it has faces, if you middle click on those ObjectMerge nodes you can view their basic content such as points, primitives, volumes etc...

 

I was suggesting you morph between two geometry based objects, which will give you a fairly smooth transition. Once that is working and in place just use the pyro shelf tool on top of it to turn it into a pyro sim and use the expression to activate it somewhere in the middle of the morph.

 

But I am not sure if that really fits your needs for this project.

 

 

ap_morph_two_shapes_explode.hipnc

[ISUther]

Yeah it seems easy when i but when i dive inside there are many things that are not mentioned. 
Expressions you use there..
+ You did not use Merge object in to as you created 2 separate objects inside GEO NODE
I have to import objects outside of GEO node. 
And i go wrong there somewhere.
Note! My geometry animates and animation is NOT created using riging 
Here is more info what tutorial i used to create this object
http://cgterminal.com/2016/01/27/houdini-after-effects-liquid-spider-effect-tutorial/