How to use camera to make split screen or small map?

Cocos Creator
#1

Hi all Cocos Creator users!
I’ve just upgraded from 1.9.3 to 2.0.9 and found out many changes with camera.

As mentioned here: https://docs.cocos2d-x.org/creator/manual/en/render/camera.html

Multi-camera support allows you to easily implement advanced customization effects, such as the two-player split screen effect, or the creation of a small scene map

So I wonder how to implement the split screen or a small map using camera?
I’ve searched the docs as well as forum with no luck.

As I know the camera will flush all it captures directly to entire viewport screen. How do we restrict the render area of a camera, so, smthing like output of camera 1 renders only to left half and camera 2 to right half of screen?

Thanks in advance for any suggestion!
And many thanks to @slackmoehrle if you could help.

#2

Lets ask @Big_Bear for how to use this. My initial thought is more than one camera, but I’m not sure if that is correct for Creator. In Cocos2d-x I would just use multiple cameras.

#3

Refenece this minimap demo:https://github.com/ayarami/CameraMiniMapExamples.git

2 Likes
#4

Thanks @Big_Bear
I’ve tested your example code and found out that it calls to renderTexture every frame
Is that performance wise? Could it be more efficient if I clone another instance of the entire map-node to put into the mini-map and just update the position changes from real-map?

#5

Tested minimap demo of @Big_Bear with Cocos 2.0.9 on laptop core i5 Kabylake + NVIDIA Geforce gtx 1050 and result went like…

The simulator ran well for 1 minute and caused the whole laptop to hang for another 1 minute before I can close the simulator.

#6

this demo is just an example, it shows how to implement the minimap with camera, but I did not think about performance.

you can optimized it, e.g every frame new a SpriteFrame is a bad realization, you can just replace with using the “setTexture”

#7

Hi @Big_Bear
I’ve tried to optimize using setTexture() as you suggested but the frame-time kept showing 30-35 and fps dropped to 10-20 fps.
I think renderTexture() should be the culprit. Maybe something different between Creator & 2dx.
Anyway. you’re the one who wrote the core functions, your suggestion should be the best advice.

#8

I redraw all the necessary parts of real map inside mini map. And performance is not bad. Honestly.

#9

how would you use multiple cameras to make a split screen?