[AWOL]

Hi!

I'm wondering if there is any way of rotating an image based environment around all three axis?
Under the environment tab I can offset the U and V values, but that's only two out of three...
Any way to solve this?

Thanks!

/ Andreas

[Mihai]

It's mapped to a virtual sphere that encompasses your scene, it's not an actual object. So the U,V just remaps the hdr on this environment, you can't move it in Z to bring parts of it closer to your scene. You can instead map the hdr to a real sphere and move it as you want, but what is the problem you're having exactly?

[AWOL]

Thanks for the answer Mihai.

When I work with the regular sky object in Cinema, I can rotate it freely around all three axis. I'm not trying to move it closer to my scene, merely rotate it in any direction to control the positioning of reflections etc. As it is now, I can adjust the mapping somewhat, but it doesn't give me the level of control that I would like.

I will try the method you mentioned, mapping the HDR to a sphere. Is there any actual render speed difference between using a mapped sphere and the Maxwell Scene Object Environment tab? Should the sphere have a specific polygon count or size for optimal performance?

[JDHill]

Environment positioning is restricted in the Scene Object because it is just exposing to your view and control the parameters which Maxwell supports internally. I could not say what an optimized geometry might be for making your own HDR environment manually, so let us know what you find and maybe I can put that info into a 'tips & tricks' section of the manual for the next version. As far as speed goes, I don't guess there should be much difference, but I suppose there may also be some optimizations possible within the engine when it is working with its own self-defined setup, so it would be hard to make an authoratative statement without doing some specific testing. It does strike me as somewhat strange to want to rotate a spherical environment in an arbitrary way, but maybe I'm not grasping your particular requirements. Just keep in mind that your sphere will need to remain centered on the camera's location at all times if you want to avoid mapping-distortion.

[AWOL]

I have to admit I don't fully understand what you are saying in the first sentence about environment positioning restrictions, possibly due to English not being my first language, or perhaps my brain is beginning to slow down at the end of the work day...

Wanting to rotate an HDRI map might seem strange, but in this particular case I'm creating a chrome logo, and lighting it with a HDR with some light objects. Let's say for instance I have a nice reflection going on with a softbox gradient reflecting in an object, but it needs a little rotating to be just right, then instead of having to rotate my entire scene, I just rotate the environment sphere to get the reflection I'm after.

I did some quick testing with a mapped sphere, and it seems to work quite well. Can't tell if there is any speed difference, and I haven't been keeping track of exact render times so far. If I find anything specific about what seems to be optimal geometry, I'll post it.

Thanks for the tip regarding centering the sphere around the camera, hadn't thought about that.

[JDHill]

Sorry, all I meant was that the Scene Object only allows you to show the image-based environment as Maxwell can render it - I could put in arbitrary rotation controls and make them work in the Cinema display, but there would be no way to render the environment you would create with them.