RTS Camera

Unity Engine
1

Hey,

I tried to implement a RTS-Camera using the Free-Look Component.
Using the v2.0 Release Candidate.

Adding External Input was not as bad as I have thought.
But when trying to add features like zoom to position or rotate around position it gets problematic.

I think those features would be nice to have in the main file instead of trying to add it afterwards.
Adding it afterwards intruduces many problems like jittering or other bugs.

Nice-to-have Features:
=> Easily Add Input from outside (AddInput(float amount) for every axis)
=> Drag (Move the Camera on Axis,
=> Zoom at all (Changing Radius and HeightOffset)
=> Zoom to position (Needs to change position and above)
=> Rotate Around position (Needs to Rotate and change position)

Does someone have a working code for adding zoom to position to the free-look camera?

2

Hi @ADoby . . RTS cameras, they are an interesting challenge for sure. They seem like a relatively straightforward problem but there are sure some devils in the details to make them great. We spent a long time on DoK getting them to feel right - height, FOV, acce/decelā€¦ a lot of things have to be balanced.

We are going to discuss making a default RTS camera rig, itā€™s a good idea. We also have a new feature which is in testing that keep multiple objects on screen - a dynamic framing component. We will make a post when itā€™s updated in the CM 2.0 release candidate (we really need to finish the documentation and example scenes instead of making new features but itā€™s just too much fun)

In the meantime, there are a few tricks which will help. Have CM target / follow a dummy object which you move programatically. You can snap this object to wherever and use CMā€™s damping to smooth things out if needed. You can use an Orbital Transposer on the Body and then rotate the heading to get orbits around this dummy object(s) - you might want to have a separate dummy for the target and one for the follow.

This is a bit of a ā€˜marionetteā€™ rig for CM where you drive the camera with code-placed-animated dummy targets. I hope that helps and weā€™ll let you know how it goes with a custom CM RTS rig.

3

@ADoby Just checking in to see if youā€™ve got the RTS camera going. If you follow Adamā€™s suggestions, it should be pretty straightforward, and you should not be getting any jittering or other issues.

4

@Gregoryl The RTS-Camera itself works fine.
I have only two problems left.
One is based on Mouse ScrollWheel Input for Zooming, which I have to figure out myself.
It is a problem to find the start and end of input, when it doesnā€™t have a clear start and end like a scrollwheel with damping.

The other is a timing problem which leads to jumping of the camera for one frame.
My current workaround for Zoom-To-Cursor:

When Input Starts:

  1. Raycast the world to get the current cursor position in World
  2. Place a plane at that position (to get movement only in x-z coordinates)
    Every Update (After Camera did Update Position):
  3. Let the Cinemachine Rig update its position
  4. Raycast against the created plane to get the difference the cursor made in world coordinates
  5. Move the ā€œfollowā€ transform in the oposite direction

With this I end up locking the cursor to its position in world coordinates (zoom to cursor)

But for some reason the camera movement seems to happen one frame before I can calculate the differences.
I have to investigate why that is.
Maybe something with the Smart Updating Feature.

We wanted to add these features outside (with modules) instead of creating one big super camera script.
But it creates problems with timing and stuff.

5

@ADoby Iā€™m not sure I entirely understand what youā€™re trying to do. Just to confirm, here is what Iā€™ve understood so far:

  • Using FreeLook to make an RTS camera
  • X axis of the FreeLook circles the target
  • Y axis on the FreeLook zooms in and out
  • You have created an invisible target for the FreeLook to follow and look at
  • You want the scroll wheel to control the Y axis

Is this right so far?
Here is what I donā€™t understand:

  • What is controlling the X axis?
  • What is controlling the cursor position?
1 Like
6

@Gregoryl
No sorry, that is probably my failure explaining it.
I have:

  • The FreeLook Cinemachine Component
  • The FreeLook Component works as is, x axis defines active rig, y axis rotates around the follow transform
  • I added Components to create external input (like multitouch gestures for rotating)
  • I added a Component that changes the Radius and HeightOffset of ALL Rigs based on a zoom value (changed by scrollwheel or pinch gesture)
  • I added a Component that rotates the follow transform around the cursor position instead of using the y-axis of freelook to create the Rotate-Around-Cursor feature. This is toggleable.
  • I added a Component that drags the follow transform around using the cursor delta

The zoom components Zoom-To-Cursor feature works as follows:

  1. Whenever Input starts I raycast the current input world position and create a plane on that point with normal Vector3.up.
    2.1. The input changes all rigs heightoffset and radius first then
    2.2. While Input is on (you are zooming) I raycast against the created plane to calculate the deltamovement your cursor did in 3D-space
  2. I move the follow transform in the oposite direction so that the cursor stays at its world position
    => Tada, zoom to cursor position

The zoom component does not work correctly, probably because it needs to wait for the CinemachineRig to update the rigs.

I hope this is more informative.

1 Like
7

@Gregoryl If you want to have a look at it, I can send you a package.
Not in public i guess :stuck_out_tongue:

8

@ADoby Still trying to understand zoom-to-cursor.
Letā€™s assume youā€™re using a mouse.
So you point somewhere in your game view and move the scroll wheel. The behaviour you want is that the camera centers itself around the world point where you first started scrolling, and the radius/height adjusts in accordance with the scrolling direction? Is that right?

9

Yes, it would help a lot if you send me a package.

10

@Adam_Myhill @Gregoryl Any news on the RTS rig? Iā€™d be interested in a camera that you can move when moving the mouse cursor the screen borders and with WASD, scroll to zoom, orbit the dummy target when scroll wheel is pressed, center on a transform when pressing space and (probabyl the most tricky part) handle height differences in the scene gracefully. This means not clipping into buildings, and keeping a good distance to terrain of varying height for example.

11

Hi there; Iā€™m trying to get something similar to what @Daerst above is describing, although a bit simpler. Iā€™m aiming for a looking down camera with a fixed perspective (not completely), so Iā€™ve set it up like that:

3386592--266095--upload_2018-2-9_22-53-1.png
3386592--266095--upload_2018-2-9_22-53-1.png428Ɨ939 36.4 KB

Now, whenever I ā€œzoomā€ in and out, the camera rotates slightly on the Y axis with the following values

altitude | rotation
   8     |   0.331
   16    |  -0.733
   42    |   0.662

that rotation ping pongs between the key values of the rig (meaning it goes from 0.33 to -0.733, then back to 0.662) and I just donā€™t understand why. These values are consistent regardless of altitude values.

Anything that Iā€™m missing in the configuration here that would lock the Y axis in place when zooming in/out ?

And while Iā€™m on the subject: say I want to restrict rotation on specific angles (eg have the camera stick to the angles 0, 90, 180, 270) but still take advantage of the Free Look rig helper, is there already something like that, or I should explore having a composite object with multiple virtual cameras and blend between them?

12

@fderudder I think itā€™s because you have ā€œdo nothingā€ in the Aim for the rigs. So the orientations in the 3 rigs are whatever they are, not being initialized. Try setting them to Hard Look At.

For the second question, have a look at this thread: 90* Camera Rotations while following? - Unity Engine - Unity Discussions . The solution can be easily adapted to work with the FreeLook.

13

@Gregoryl Ah fantastic, that was exactly that. Setting to Hard Look at fixed that slight rotation. Iā€™ll have a look at the thread you just linked, which seems to be exactly what I needed. Cheers!

14

Gonna revive this thread because Iā€™m stuck with the same issue.

We never got a proper answer on how we could achieve zoom to cursor using cinemachine.
I have my own implementation using standard camera which works same way as ADoby described, but Iā€™d like to move to Cinemachineā€™s virtual cam.

15

Anything that works with a standard camera will also work with a vcam. No need to rewrite your working code. Just replace the Unity Camera component with a vcam (with ā€œDo Nothingā€ in Aim and Body so it wonā€™t interfere with your camera controller). Then, make a new Unity Camera - with a CinemachineBrain - at the root and youā€™re done.

Thanks to the Brain, the Unity Camera will now be driven by the vcamā€™s transform. You can add noise, collision, or any other extension to your vcam and it will work fine. Blends to other vcams and Timeline integration will work too.

See this thread for a pretty picture: https://forum.unity.com/threads/multiple-raw-pos-for-one-vcam-possible.525199/#post-3455994

16

I fixed my issue by changing cameraā€™s fov and pos directly instead of messing with vcamā€™s properties.

The issue was the fact that vcam would only update at the end of the frame ( or so it seems ), so I couldnā€™t execute my zoom-to-mouse code properly.

This zoom method required changing the cameraā€™s position ( and fov in my case ), do raycast, then translate it to correct its position. When I tried doing that to vcam, it didnā€™t update cameraā€™s view projection matrix, so the raycast still used old cameraā€™s properties, from the previous frame, resulting in a stuttery translation and a really unsatisfying zoom.

What would be a great-to-have-feature is the ability to manually update vcam, that would solve a lot of issues and allow advanced users to do some wicked vodoo magic.

17

@Xerioz Ah, I understand the issue now.
The Cameraā€™s transform is updated in LateUpdate, by CinemachineBrain. To do something after the update, you would do it in the LateUpdate() of your script, then set the script execution order to make your script execute after CinemachineBrain.

18

If anybody fell upon this via a Google search Iā€™ve built an orthographic RTS Cinemachine camera example repo you can find at the link below. It demonstrates how to setup the camera, use forward movement projection, and work with other Cinemachine cameras on the fly.

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