when i create a scene and put in two sky objects.
First only visible GI, and the second visible in cam/refl and refr the rendered picture is always an alpha.
I know that this method is not the cleanest. Nevertheless, it worked with V7.
Has something changed approaching that with V8?
Can you explain what you mean “the rendered picture is always an alpha”, as I don’t understand that part. Thanks! e.g. is this when you save, if so, what format are you saving to? Do you mean in the VFB itself? Can you show an image demonstrating what that looks like?
The error message that the scene has caused a NaN is the most important part there, but wasn’t mentioned in your description - something is broken in the scene and the support and dev team will need to have a look into it.
i want to have special hdri lighting in the scene. But the visible and reflecting hdri map should be another.
For example the hdri map should be cloud free, with clean bright light and shadow. But the visible sky could have a couple clouds. And this hdri should be visible reflection so the scene feels more dense.
For me it’s the reason for not using v.8 yet
You could also use 2 Corona sky objects with their own HDRI. Add some compositing tags to make what you want for the light and what is to be seen. As you can see here. Although, it looks completely unnatural.