openGL bug in Unity 5.4, illegal operation?

Questions & Answers
1

Hello,

I am working on an app for iOS 9.3 on Mac OSX 10.11 and I get this message looping in the editor but it doesn’t cause a crash or any bug :

OPENGL NATIVE PLUG-IN ERROR: GL_INVALID_OPERATION: Operation illegal in current state

This message is also present when I build in this form :

Invalid OpenGLES Api usage detected.

This happens with OpenGLES 2.0 and OpenGLES 3.0.

My scene all crash after a few seconds and it’s always related to OpenGL.

Did this happen to anyone before? I assume I forgot something at some point but I really have no clue.

Thanks for your answer(s)!

2

Well, you most likely are using a native code plugin which has some errors in them. Most likely a wrong order or instructions. For example “glVertex” can only be called inside a glBegin / glEnd pair. If executed outside it would throw such an error. OpenGL is a statemachine and some operations are only allowed / possible when in a certain state.

3

I had this bug because I was trying to read pixels into a TextureFormat.ARGB32 from a RenderTexture.RGBAFloat. I fixed by specifying the TextureFormat in Texture2D constructor to match when creating the reading texture.

	outputTexture = new RenderTexture (128, 128, 0, RenderTextureFormat.ARGBFloat);
	RenderTexture.active = outputTexture;

	tmpTexture = new Texture2D (outputTexture.width, outputTexture.height, TextureFormat.RGBAFloat, false); // NOTE: MUST MATCH FORMAT OF ACTIVE RENDERTEXTURE!

	tmpTexture.ReadPixels (new Rect (0, 0, outputTexture.width, outputTexture.height), 0, 0, false);
	tmpTexture.Apply ();
	RenderTexture.active = null;