Explosion help!

[Dark_Jedi]

Quick, I need to know if anyone has a fast and easy explosion available that wont slow the program down alot?

[johnl3d]

you can control the explosion material on the cd by adjusting the emiting percent

[Woloshyniuk]

thanks that helps the slowness problem while working in choroegraphy.. Do you have any idea how to enlarge the explosion? It is too small compared to the objects that must explode. We cant just click and drag the emitting sphere of the explosion because this makes the explosion spread out rather than enlarge. Any help would be awesome because we are out of time trying to figure out all these problems.

[johnl3d]

change the size of the sprites and the velocity ?

[Woloshyniuk]

we've tried that as well. The problem is that it is impossible for us to change the size of each different sprite emitter at the same ratio. so in the end the explosion looks way way different. This is because all the percentages that are shown in the properties are not shown. They all just say 100 and we have found out that those are not the true values of each property of the different sprite emitterrs. If i multiply each size by 10 in each emitter, the explosion looks very different (not in a good way)

[Bruce Del Porte]

Many times solid models scale easier than sprites.

 

If you like the way the explosion looks but it is too small in comparison to the object being exploded. Make the explosion and object a separate cut. Scale the object at time zero in the chor to the size you want verses the explosion, then just zoom the camera in. Scale to the set as a composite (or scale the set too).

[Woloshyniuk]

good thinking, i was considering this but it would not work for 99 percent of my shots since i have tons of different models in each scene it. It would take absolutely forever to scale down everything for each explosion and zoom in just right. ALso, much of the time, the explosions are not the focal point of the scene and they are in the background making it impossible to do this.

[frosteternal]

good thinking, i was considering this but it would not work for 99 percent of my shots since i have tons of different models in each scene it. It would take absolutely forever to scale down everything for each explosion and zoom in just right. ALso, much of the time, the explosions are not the focal point of the scene and they are in the background making it impossible to do this.

Render out the explosion at a very high resolution at double or triple the frame rate with an alpha channel, then use the resulting animation as a Layer object in the choreography. You can animate the frames in each layer in the choreography to make the explosions last different time periods (that's why you want the extra frames). You can also alter the size of the layer object per-instance. This is not only easy to set up, but eliminates the delay to re-process particles when you scrub through frames. If you need more variation/complexity, you can use this technique in addition to sparsely populated sprite explosions, or render out 3 or 4 different versions of explosions to use.

This is the easiest method, and will render most efficiently.

[Woloshyniuk]

so render explosion in choreography by itself with lots of frames and alpha (i dont know wut that is), then stick the video image into an existing choreography and the movie file will play inside the choreography? This is an idea i had yesterday and you seem to understand it better. It sounds like it will work, but what if there are objects behind the explosion? Will the model that the video file is playing on be seen if objects are behind? Cuz when i render the explosion first, it will obviously have a background attached to it. Is there a way to rotoscope or cut out the background? Is that what the alpha channel does? Im not shure what the alpha channel is used for

[Rodney]

and alpha (i dont know wut that is),

 

Most definitely need to learn what that is.

 

Powerful options and new worlds of graphics opportunities open up to you through alpha channels.

[frosteternal]

...Will the model that the video file is playing on be seen if objects are behind? Cuz when i render the explosion first, it will obviously have a background attached to it. Is there a way to rotoscope or cut out the background? Is that what the alpha channel does?

The Alpha channel is an extra bit of data usually embedded into a targa file (in A:M). It is best thought of as a "Transparency" layer.

The Alpha Channel is going to become your New Best Friend.

The explosion will render, but the background of the render will be see-thru. Also, if parts of the explosion are semi-opaque, that will be saved too. So it should be almost indistinguishable from a non-prerendered particle explosion.

So cool.

The object that you use to put these explosions into the scene are called "Layers". They are basically rectangular, 2-D images that can be moved in 3-D space, like a cardboard cut-out. To create one, right-click (or ctrl click) on the choreography, and choose "New:Layer" from the context menu.

Without The Alpha channel, the world of 3-D animation would be a much more dismal place indeed!

(I've attached a zip file of a quick version of what I mean in a v12 project you can load to dissect and figure out if you like)

ExplodeDemo.zip

[Woloshyniuk]

GREAT GREAT GREAT! Exactly what i was hoping to hear. I remember seeing the alpha channel but i dont remember where i go to turn it on.. Also, what resolution do u think i shud render the explosion in so i can make it shrink and grow? And what resolution do u recommend for rendering all regular scenes? Thanks so much you are a life saver

[frosteternal]

GREAT GREAT GREAT! Exactly what i was hoping to hear. I remember seeing the alpha channel but i dont remember where i go to turn it on.. Also, what resolution do u think i shud render the explosion in so i can make it shrink and grow? And what resolution do u recommend for rendering all regular scenes? Thanks so much you are a life saver

When you choose to "Render To File" under output there is a section called "Buffers". This contains the "Alpha Channel...ON" switch. (If you render to uncompressed quicktime you can also save an alpha channel, it can make it easier to manage instead of long lists of targa files.)

As far as the resolution, I would render it about double the resolution of the final product, maybe triple. Also keep in mind to set the camera far enough back so as to not have any parts of the explosion go off the edge of the rendered image. Depending how much spread the explosion has, it may be quite a large file. (1024x1024?) If it is just for a background explosion, I would use a lower-res version, maybe 640x640.

 

Glad to help, let me know if you need any more help.

[Woloshyniuk]

i cant get the project to work. Can someone send me an alpha channel prj (v12) that i can pop my explosions into and render? The one he gave me is kinda acting odd. Thanks for the help. I just need a simple project that has the alpha channel option available when i go to the advanced render options