Whole scene Radar Effect,how?

Minato

Not sure what it is actually called so i came up with that name,anyways i've had this thing on the back of my head for a long time(eversince i played Arkham City),and i keep seeing it being used left and right these days,most recent examples would be the E3 Halo 4 and Sprinter Cell:Blacklist demoes,both of which had a visor mode that when activated a scanning line radially scans the whole scene originating from the player's position,just like the Detective mode in Batman Arkham City,i tried to capture a screenshot of it in Arkham City but it happens so fast that i couldn't get a shot,but i think you know what i'm talking about,so i want to know,how can something like that be done inside UDK,is it a Post Process effect or something else?

Any nudge in the right direction is much appreciated...

JamesWild

You could do that pretty easily with a post process material.

Minato

Great,but i need a bit more than that...^^

Can you describe the process?

Visceral

I would try the cartoon edges effects, there are plenty of tutorials on that, just make the lines bright color instead. Then i would use a PP for the sceen tinting and mask it off by scene depth. Might give it a try tomorrow.

Minato

Just to clarify i'm not talking about the edge detection portion of the visor modes,but the radial scanning effect,that circle that starts at the player's(camera's) position and expands and in it's way conforms to the world geometry and keeps repeating this pattern,you know,the radar scan effect...i hope i'm making sense here...'^^

PS:Visceral it would be great if you or other people with experience with this stuff can put a quick tutorial together about this kind of technique.

JamesWild

Do you know how to use the material editor? Go find out how to put a material across the whole screen (postprocess material) and how to read the depth at a pixel (destdepth).

Minato

I'm kind of familiar with PP Materials,and have tried to create the effect with no success,i'll take a look around for what you suggested about destdepth,meanwhile i hope someone with a bit more information about this effect will give a clearer solution to my problem...

JamesWild

http://www.smallfiles.org/download/732/JamesWild_Radar.upk.html

Minato

That looks amazing!...thanks a lot for sharing it...now to figure out how to make it radial,that i will try to figure out on my own,that's not to say i won't appreciate a comment or two,lol...it's obvious that i have a lot to learn about materials...thanks again JamesWild...

JamesWild

Basically it takes the screen UV in 0>1 space, biases it to -.5>.5 space, scales it using the depth of the scene at that pixel, biases it back (unnecessary) and then scrolls it horizontally and does a crude faded vertical line (using a texture would be much better)