[WIP] Line Of Sight

Arac

I've started working on a 3D line of sight system for Unity, which could be used in top down style games.

It uses a technique very similar to (deferred) shadow mapping in addition to some custom post processing effects, shaders and scripts.

At the moment it works in both deferred and forward rendering, supports an unlimited amount of line of sight sources (technically atleast) and allows you to easily switch the image effect applied to the area outside of the line of sight.

Still need to add support for orthographic cameras and flesh out the demo scene a bit more.

Let me know what you think!

Computron

Wow, that is pretty cool. I t does get a bit hectic once you spawn a lot of the little camera things. It would probably help if the line of sight edges weren't completly hard edged.

Also, with the blur going on its a bit hard to separate the foreground and background which is a bit disorienting. Perhaps the blur should be based on distance like camera focus/ depth of field.

Arac

Thanks for your input! I think I've solved most of the issues you raised in this update.

I added a blur to the mask and a fall-off to the cones to help readability. I also swapped the blur effect with a DoF effect.



I updated the webplayer build so you can try it out if you'd like.

Computron

DAMN, that's awesome! :-D

You could do stuff with verticality where your vision cone gets bigger or the DOF gets less intensely blurred as you climb to a higher vantage point. The camera could dolly upwards and move forward along your LOS to reveal more of the map when you point your cursor further out, as a way to peer further (possible also narrowing your cone).

Also, mirrors?

Now you just need to do something for visualizing sound/noise and you got an awesome technical settup for a stealth game!

Ekibyou

Might I ask how you did it?
It looks amazing!

Lamont

Very cool!! Will give it a spin tonight!

Lamont

Ok. I like it very much.

Reminds me of Mark of the Ninja.

Arac

Glad you guys like

Made a small update to the webplayer.

I focused mostly on optimization for this update, for example making sure that (line of sight) cameras which are of screen aren't rendered, and some profiling.
I've also added basics NPC's which move around the map randomly and fade in and out of the visible area.

I'm considering turning this into a small stealth game, something like mark of the ninja gameplay wise, but than in top down 3D.


@ Ekibyou; here's a quick explanation of how the main effect works:

• Use a custom image effect to store the back buffer after the scene has finished rendering
• Apply all Image effects to main camera

Then in a loop for each LOS ( line of sight ) camera:

• Render scene again from this camera's position using a linear depth replacement shader to a render texture
• Each camera reuses the same render texture to keep memory usage constant regardless of number of LOS camera's
• Run another custom image effect which for each pixel reconstructs the world position using the main camera's depth texture and compares the distance from the LOS camera to the depth / distance stored in the depth texture we just rendered (very similar approach as shadow mapping) and creates a mask.

After all the cameras have been added to the mask:

• Blur this mask using image effects (optional)
• Use this mask to blend the original back buffer we stored before with the result of all the image effects applied.

osman

This is pretty cool! Are you going to release this by any chance?

CptAsgard

Please, please, please release the source code for this!

Arac

Hi guys,

I finally managed to finish my line of sight system and it's now available on the Unity Asset Store!









Asset Store link: http://u3d.as/content/tycho-terryn/gpu-line-of-sight
Unity Forum Thread: http://forum.unity3d.com/threads/released-gpu-line-of-sight-field-of-view.257324/

Computron

Dope.

DGoodayle

Very nice I've just signed up to the site and stumbled onto this post. Have you seen Light before?

Arac

DGoodayle wrote: »

Very nice I've just signed up to the site and stumbled onto this post. Have you seen Light before?

Hehe, off course. I used it as an inspiration for the demo

I'm guessing they're using a similar technique as well.

DGoodayle

Awesome, I'm the developer of Light so just really happy to see someone enjoyed the style!

Arac

Really cool man!

Love the design and concept of your game. What are you using to develop it?

DGoodayle

All made in Unity, so I'm going to check out your tool to see if I can get it implemented in our next project