Hello,

i am looking for a way to create a crowd simulation of archers, shooting arrows. I counldnt find any resources for a Houdini approach. The only thing i found was a Tutorial for Golaem. (https://youtu.be/Km2H04d-Nrg?t=13)

How would i create something like that in Houdini.

Thnaks in advance

The same way you would make an agent walk. Pre-Animate the character firing the arrow and make it a state. This way the character could move to a location (i.e. walk to goal). Change to a new state (i.e. fire weapon/attack) then move on to another state.

Enivob
The same way you would make an agent walk. Pre-Animate the character firing the arrow and make it a state. This way the character could move to a location (i.e. walk to goal). Change to a new state (i.e. fire weapon/attack) then move on to another state.

I'm really sorry, I just realized i posted the wrong youtube link (updated now) but here it is again https://youtu.be/Km2H04d-Nrg?t=13 [youtu.be]

its a archer scene thats shooting arrows on an enemy army and they are dynamically falling when hit.

I'm not sure if you can make a particle active (i.e. arrow launch) from within an Agent. Perhaps the Staff can weigh in on this?

What you can do is make two different archer states. One when they stand there and another when the shot if fired. So the arrow is part of the agent in the firing state.
In most of my simulations dealing with two opposing forces, I try to match the point count between the two groups. This way I can assign a goal/target point in the second group. You can orient to face the target, then transition to firing the arrow. Set a flag on the target so it transitions to a hit_by_arrow animation after a few frames (the time it takes the arrow to travel to the target).

This may work for a distant shot. If you need shots that focus on agents getting hit by arrows up close, create scene for that as well.

It would be nice to see the staff post a working solution for this scenario. I was faced with a similar situation when I wanted a crowd of dragons to each breath their own fire. I came to the conclusion it couldn't be done at the time. The crowd simulator has grown since then so maybe these types of crowd animations are possible now. Having an agent trigger a unique simulation.

Enivob
I'm not sure if you can make a particle active (i.e. arrow launch) from within an Agent. Perhaps the Staff can weigh in on this?

What you can do is make two different archer states. One when they stand there and another when the shot if fired. So the arrow is part of the agent in the firing state.
In most of my simulations dealing with two opposing forces, I try to match the point count between the two groups. This way I can assign a goal/target point in the second group. You can orient to face the target, then transition to firing the arrow. Set a flag on the target so it transitions to a hit_by_arrow animation after a few frames (the time it takes the arrow to travel to the target).

This may work for a distant shot. If you need shots that focus on agents getting hit by arrows up close, create scene for that as well.

It would be nice to see the staff post a working solution for this scenario. I was faced with a similar situation when I wanted a crowd of dragons to each breath their own fire. I came to the conclusion it couldn't be done at the time. The crowd simulator has grown since then so maybe these types of crowd animations are possible now. Having an agent trigger a unique simulation.

Sorry for maybe reviving this old old post, but this problem still percists, even with Houdini 19 just releasing. Most of the 3rd party crowd solutions that can do fun interactions, seems to be running on the physX engine for physics instead of Bullet, which is fast.. but also weirdly limited and hard to get to do some of those things, if not impossible at times.

The classic archer hitting agent, sticking! this part is so missing in houdini right now, triggering ragdoll with the arrow force applied...

Btw, the dragon breathing fire I think I have solved this setup checks if the dragon agent is in the "attack" state, then I isolate a cliptime window within that state and spawn particles from the mouth during that time only, ending up with dragons spewing a spray of particles when attacking. This was then fed into Axiom for Pyro sim'ing but it works at least.