Changing sprite color over lifetime

[Gerry]

I'm creating an explosion and I wanted to have some sprites change from yellow to red over their lifetime, i.e., from the center of the explosion to the periphery. I've been playing with settings but can't seem to find a way, or even just coloring them one color throughout. Can this be done? Or does it need to be an animated sprite?

[johnl3d]

can be done change color at material setting while adjusting time line

[Gerry]

Okay, I'm looking at the settings and on the Sprite System there's a "Tint" setting, and on the Sprite Emitter there's a "Color Method" and "Color" settings, but I can't really tell if one or the other is having any effect at all.

 

I've got the material window open, and the timeline for the explosion chor, and I'm setting *something* on the timeline, but as yet it's hard to tell what's what.

 

When I have a clear question I'll be back!

[robcat2075]

Keyframing the color under "Color Method" will cause the sprite to change colors but it seems change much faster than the lifetime of the sprite

[robcat2075]

In my initial investigation i seems that if i set the "life" of the sprite to 5:00 (i regard that as 5 seconds) it really only lives 5 frames. Do you get that?

[Gerry]

Yeah, "life" is generally in frames. I think most of those settings are unless they're in percent or inches or some other measure.

[robcat2075]

but "5:00" should equal five seconds, not five frames. 0:05 should equal five frames.

[Gerry]

Oh I see, I guess it depends on how you have your units set?

[robcat2075]

Aha... you shouldn't key the color over life while the timeline is displaying frames. You have to switch to the curve editor to make it display the % on the timeline, meaning percent of the life.

 

Internally A:M represents 100% as 1:40:00 and that's what you see if you don't switch to the curve editor. If you try to key a color at 5:00 on that you will really be keying it at some tiny portion of 100%

 

 

Now, why does it create red when i try to key black...

[Gerry]

Well, not to switch gears here, but I just remembered another cross-platform issue. This may have been fixed in v17 but for the time being I'm not switching versions in the middle of a big project.

 

When moving my files from the pc to the mac and back again, I've noticed that particle systems lose all their settings. so when I took this home last night I had to completely redo all the particle settings, then this morning back on the pc, they're all lost (i.e., reverted to defaults) again.

 

So I'm recreating them *again* and once set I'll just have to decide to work on this particular scene (pun intended? I can't tell) on either one machine or the other. Or maybe once I get them where I want them, bake them in? Haven't baked before and just tried it this morning for the first time and I can't tell if anything happened.

[robcat2075]

Here's how to do color-changing sprites:

 

Create a sprite material in the materials folder

 

drop it on the emitter group of your model

 

Put that model in a chor

 

Have the Chor window open and visible.

 

Back at the original sprite material in the PWS>Materials folder, expand Sprite System>Sprite Emitter

 

Set "Life" to a time in seconds:frames

 

Expand Color Method> Color

 

Set Color Method to "Over Life"

 

Switch the PWS timeline window to curve-editor view

 

The units at the top will now be percent, not time

 

scale that window until all 100% is visible

 

keyframe some color setting at 0% (the start of the sprite's life)

 

keyframe some color at 100% (the end of the sprite's life)

 

keyframe anything inbetween.

 

Because the color keyframes are mapped out over "1:40:00" as representing 100% you will need to switch back to the non-curve-editor view of the timeline and zoom back in to test scrub a few seconds in your chor.

 

 

Notice in this test example I also set "Use Additive Color" to OFF, so that teh exact keyframed colors would be displayed on the sprites instead of their color values being "added" to the background. This keeps black (0,0,0) from being invisible.

 

SpriteColorChange04.zip

 

 

 

 

Well, not to switch gears here, but I just remembered another cross-platform issue. This may have been fixed in v17 but for the time being I'm not switching versions in the middle of a big project.

 

When moving my files from the pc to the mac and back again, I've noticed that particle systems lose all their settings. so when I took this home last night I had to completely redo all the particle settings, then this morning back on the pc, they're all lost (i.e., reverted to defaults) again.

 

That certainly shouldn't happen since the particle settings should be the same text in the file whether it's a PC or Mac file.

[markw]

Well, not to switch gears here, but I just remembered another cross-platform issue. This may have been fixed in v17 but for the time being I'm not switching versions in the middle of a big project.

 

When moving my files from the pc to the mac and back again, I've noticed that particle systems lose all their settings. so when I took this home last night I had to completely redo all the particle settings, then this morning back on the pc, they're all lost (i.e., reverted to defaults) again.

 

So I'm recreating them *again* and once set I'll just have to decide to work on this particular scene (pun intended? I can't tell) on either one machine or the other. Or maybe once I get them where I want them, bake them in? Haven't baked before and just tried it this morning for the first time and I can't tell if anything happened.

That's frustrating Gerry!

Is this happening when you save the Particle Systems inside of Projects and/or Chor's?

Just a thought but have you tried saving the Particle systems as separate Material files on their own outside of any AM .prj or .cho.

After swapping computers and starting up the project/chor on the other computer, reimport the Particle Systems from those separate files. Do they still revert back to defaults then?

[Gerry]

Sorry, I spoke too soon! When I closed down, and reopened the files, particles are back where they should be. It definitely happened last night on the Mac, and this morning on the pc, but last night it never occurred to me to close and reopen. I may tweak some things but other wise things seem fine.

 

Robert, thanks for the clear instrux. I believe I've done all that but didn't understand the scope/purpose of the "percent" timeline. I'll try it again but as it turns out the explosion I'm creating happens too fast for a color change to make a difference. I'll be posting a test shortly.

[robcat2075]

Robert, thanks for the clear instrux. I believe I've done all that but didn't understand the scope/purpose of the "percent" timeline. I'll try it again but as it turns out the explosion I'm creating happens too fast for a color change to make a difference. I'll be posting a test shortly.

 

Defining color changes as a "percent" of the sprite's lifespan means you can later edit the lifespan of the sprite and not have to go back and adjust all the color keys to suit the new lifespan.

 

When the sprites lifespan is 2 seconds, the color you have keyed at 50% will happen at 1 second. If you change the sprite's lifespan to 3 seconds the color you have keyed at 50% will now happen at 1 1/2 seconds.