How do I link Position and Scale?

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Hi everyone,

I am an animator and not a programmer so please bare with me as I do my best to ask a programmy question :)

I created a photoshop scene which has 3 layers: Foreground, Midground and Background.

I imported these layers onto 3 separate planes in Unity as textures and set the planes up in 3D space so I could create a parallax effect between the 3 layers when I move the camera.

When I moved the Midground and Foreground planes closer to the camera I had to scale them down so they maintained the correct size in relation to the Background.

Does anyone know if there a way in Unity to link the position and scale properties of a plane? I have lots of scenes to set up in Unity so it would be awesome if the planes scaled down automatically as I moved them closer to the camera.

Thanks

Answer 1

Answer by flaviusxvii · Jun 23, 2011 at 04:33 PM

You probably want an Orthographic camera.

http://unity3d.com/support/documentation/Components/class-Camera.html

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TamboFirstBlood · Jun 23, 2011 at 04:39 PM 0

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Thanks for the speedy response. Unfortunately with an Orthographic camera there won't be any sense of 3D space/Depth to the scene i.e. the Foreground, $$anonymous$$idground and Background planes will all move together at the same speed when I move the camera and there won't be any parallaxing effect.

flaviusxvii · Jun 23, 2011 at 05:04 PM 0

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Ah.. I misunderstood you. In that case I'd use this http://unity3d.com/support/documentation/ScriptReference/GeometryUtility.CalculateFrustumPlanes.html and then interpolate between the height of the close plane and the far plane to get the right height for any give layer at any given distance.

Graham-Dunnett ♦♦ · Jun 23, 2011 at 05:56 PM 0

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but you could move the foreground, middle and background planes at different speeds to recreate the parallex effect.

flaviusxvii · Jun 23, 2011 at 06:38 PM 0

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I was right all along! Brava to me!

Answer 2

Answer by sneftel · Jun 23, 2011 at 05:05 PM

Here, try this script. The "scale" parameter is the global scale factor, which should be set the same for all layers. Change "targetCamera" if you want a camera other than the main camera controlling the scale.

 using UnityEngine;
 
 [ExecuteInEditMode]
 class ScaleFromDistance : MonoBehaviour
 {
     public Camera targetCamera = null;
     public float scale = 1;
     void Update()
     {
         Camera usedTargetCamera = (targetCamera == null) ? Camera.main : targetCamera;
         float overallScale = scale * usedTargetCamera.transform.InverseTransformPoint(transform.position).z;
         transform.localScale = Vector3.one * overallScale;
         if (Application.isPlaying)
         {
             Destroy(this);
         }
     }
 }

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How do I link Position and Scale?

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