How do I set RenderSetting.customReflection using a cubemap RenderTexture?

[Geeoff]

Hi people,

I’m trying to set RenderSettings.customReflection with a RenderTexture, but I’m not sure how or if this is even possible. I can create a RenderTexture that is a cubemap, but I can’t get a Cubemap object from that to plug into RenderSettings.customReflection.

I tried casting but it gives “error CS0039: Cannot convert type UnityEngine.RenderTexture' to UnityEngine.Cubemap’ via a built-in conversion”

I tried casting to a Texture and then a Cubemap, but then I just get null. That makes sense, but it was worth a try.

Haven’t been able to find any conversion methods. Seems like this should be possible. Am I missing anything? Maybe I should submit a feature request?

[alexandre-fiset]

Hey there!

To achieve what you want, I would suggest creating a giant Reflection Probe around your environment and add a script that uses the ReflectionProbe.BlendCubeMap() function.

This will return a RenderTexture that you can assign by script in the probe. The function is quite efficient (~0.3 ms). Here’s a simple proof-of-concept script:

using UnityEngine;
using System.Collections;

[RequireComponent (typeof (ReflectionProbe))]
public class BlendReflection : MonoBehaviour {

	[SerializeField] Cubemap cubemap1;
	[SerializeField] Cubemap cubemap2;
	[Range(0.0F, 1F)] [SerializeField] float blendFactor;
	RenderTexture renderTexture;
	ReflectionProbe probe;

	public void Start () 
	{
		probe = this.GetComponent<ReflectionProbe> ();
		probe.mode = UnityEngine.Rendering.ReflectionProbeMode.Custom;
		renderTexture = new RenderTexture (cubemap1.height, cubemap1.height, 0, RenderTextureFormat.ARGBHalf);
		renderTexture.useMipMap = true;
		renderTexture.isCubemap = true;
		probe.customBakedTexture = renderTexture;
	}
	

	public void Update () 
	{
		if (probe != null && cubemap1 != null && cubemap2 !=null) 
		{
			ReflectionProbe.BlendCubemap (cubemap1, cubemap2, blendFactor, renderTexture);
		}
	}
}

Simply add this script to a probe, set the two cubemap, press play and use the slider to see it blend between the two maps. This will work on all objects affected by the probe.