WHy cant I create the GetComponentsInChildren(Renderer) array?

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I get the following error at this line: InvalidCastException: Cannot cast from source type to destination type.
I’m really not sure why, as the code emulates the documentation perfectly. Is theresomething unique about renderer types?

var objectRenderers : Renderer[];
objectRenderers=downloadedAssetBundle.GetComponentsInChildren(Renderer);

Note: downloadedAssetBundle is an instantiated mainAsset (GameObject) from an asset bundle.

2 Answers

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This is why I hate UnityScript. GetComponentsInChildren return type is Component[], and objectRenderers is Renderer[]. The compiler should be smart and try to do a cast automatically or at least show a compile-time error stating that the types don’t match. But no, it accepts your code and crash at runtime… < / rant>

A manual cast to Renderer[] should work:

var objectRenderers : Renderer[];
objectRenderers=downloadedAssetBundle.GetComponentsInChildren(Renderer) as Renderer[];

Well this manages to get past the initial error but then when I get to the next line which reads for (var eachPart : Renderer in objectRenderers) --(exactly the same as documentation) it crashes because it looks like the objectRenderers array doesn't actually exist. Any idea? Thanks!

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My bad. The code I posted actually doesn't work. Apparently its not possible to cast the entire array, but you can cast individual element of it in the "foreach" loop. //objectRenderers will be a Component[] var objectRenderers = downloadedAssetBundle.GetComponentsInChildren(Renderer); for (var eachPart : Renderer in objectRenderers) { ...

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Huh? That's the code I had originally which didn't work..Did you miss something? I tried doing var objectRenderers = downloadedAssetBundle.GetComponentsInChildren(Renderer); for (var eachPart : Renderer in objectRenderers as Renderer) {.. but that didnt work either :(

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Not really. This way I'm not declaring the type of objectRenderers and letting the compiler choose one. In this case it will be Component[]. Sometimes UnityScript behaves differently between versions. What version of Unity are you using?

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Ahha. I removed the declaration and it worked!! Many thanks!!

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3

Here’s the final piece of working code. Note: objectRenderers is never declared. If you do declare it , it will crash.

objectRenderers=downloadedAssetBundle.GetComponentsInChildren( Renderer );
		
for (var eachPart : Renderer  in objectRenderers ) //as Renderer??
	{
		//set a transparent shader
		eachPart.sharedMaterial.shader = Shader.Find ("Transparent/Diffuse");
		eachPart.sharedMaterial.color = Color.blue;
		eachPart.sharedMaterial.color.a=0.3;
	}