[SOLVED] Question about decals LifeTime & FadeTime (V.2.4.1)

[Gmarquez]

Hello there!

Fist of all I must to say that sadly I'm using the 2.4.1 version. I'm new in the proyect and we are still stuck in this old version.

Now, I'm trying to create an effect of shot impact on water.

First I tried to use particles, but the impact return the normal of the impact point, so the particle system is oriented over the surface and the flat particles get aligned over the surface of the water but the effect is nor very good.

Then I trun my efforts to achive this effect with decalOrtho, using the water decal property to proyect the texture over the water much more accurate, but the decal last for ever over the water surface.

So I say, let's go to adjust the life time and the fade time in the decalOrtho properties, but whatever the life time I set, the decal is no more painted over the water surface.

The fade time is not affecting the behaviour of the decal. I can set it to 1 or 10 and it not change the time it last in fade out. Actually the decal don't fade out.

So I'm stuck in the problem whish is, if I set the life time to -1.000, so the decal will be painter over the water forever. If I set the life time of the decalOrtho to anything (from 1.000 to 10.000) the decalOrtho is no proyected over the water (whatever the fade time).

This behaviour happens in the editor and also in the running application.

What am I missing or doing wrong?

The documentation about the decals in version 2.4.1 is really clear, but following it I can't get anything more than this.

Thank you for your support.

Edited August 25, 2021 by Gmarquez

[silent]

Gmarquez

Could you please send us a small example of what you are already achieved with the water decals? You can create a new blank project and replicate the things as it goes in your production project. After that send us the contents of data directory. Our artists will check if it would be possible to achieve such effect in 2.4.x version.

Also it would be nice if you can send us a couple of references that you are using for building this visual effect.

Thanks!

[Gmarquez]

Hi silent, due to security protocols in the company, I can't share any file, but I could take some pictures with the phone.

As reference, you can see in this video the spray and the foam created when the round fired impact the water.

The effect of the spray is done easy with a particle system.

The foam is what I want to do with a water decal.

The documentation of the Orthographic Decal says:

Life-time Parameters
Life-time and fade-out parameters:

Life time    A time period during which the decal will be projected, in seconds.
Fade time    A time period during which the decal will fade away (after its life time exceeds), in seconds.

 

With the default paramentes the water decal is visible

 

But when I set the Life time to anything different to -1.000, the decal is no more visible.

Edited August 25, 2021 by Gmarquez

[Gmarquez]

Doing more testing I think that I have found something which could explain what is happening to me.

I opened a testing world (the simulation was paused by default). I created a decalOrtho node, setted the material.

Later I have set the lifeTime of the decalOrtho to 3 seconds, fade time is 1.000 by default.
I have unpaused the simulation (Ctrl+Spacebar) and the decal have started to fadeout after 3 seconds. Cool!!. I never had seen before a decal fading out.

Now I want to reproduce again the fadeout effect, so I disable and enable the decalOrtho, but it is not shown anymore so I had paused the simulation.

The total time played with the simulation active is about 10 seconds

Now I had setted the lifeTime to 50 seconds, the fadeTime to 10 seconds, and unpaused the simulation.
The decal was then shown and after 40 seconds it start to fade out.

So I guess that the Time used to calculate the lifeTime of the decal is no the time that the node was enable, but else the total time of simulation lasted.
Is it correct?

 

[silent]

Gmarquez

Yeah, while I did my tests I've found similar behavior. Looks like the lifetime is more looks like a total time.

So I guess there is no really point to change this value, since in real world projects you more likely always need this parameter to be set to -1 (because you never know when you would need to spawn some particles and decals).

Thanks!

[Gmarquez]

Is there any way to recover the total time the world is running? I guess the answer is no, I must to ask it ;)

Edited August 25, 2021 by Gmarquez

[silent]

There is Game::getTime(), but it doesn't take in account game pauses: https://developer.unigine.com/en/docs/2.4.1/api/library/engine/class.game?rlang=cpp#getTime_float

[Gmarquez]

Thanks!!, I'll check it

[Gmarquez]

Hi there!!,

Game::getTime() works like a charm.

We have a play/pause function in our simulation, but even pausing the time, the decal works as expected.

Thank you for your support, cheers!

Edited August 25, 2021 by Gmarquez