That being said, there is a significant difference between "identifying oneself" and "producing a government-issued photo identification document". One can identify oneself by stating their name - and depending on your state's specific laws requiring or not requiring you to do so, the locality (city/county) where you reside or your street address.will probably turn out to be more trouble than you wanted over an issue that could have been resolved in the way you were hoping (not handing over a photo ID).I refuse to identify myself
And to answer your specific question - yes, you probably are obstructing by that behavior.
Generally speaking MWAG calls fall into the perameters allowing a Terry stop. But in order for the LEO to determine if a crime had been committed/was being committed/was about to be committed does not require the surrender of a photo ID document. It requires, minimally, the LEO to observe your behavior and, if he really has a reason to suspect/wants to roust you, to verify that you are not prohibitted from possessing a firearm. A name check is how they do that, and stating your name should be adequate unless he has further reason to believe you provided a false one (as opposed to wanting to roust you further).
Another issue to be looked at is whether or not you need to have a government-issued photo identification document on your person when performing the act you were performing while OCing. For example, fishing generally requires a fishing license and that usually requires you also carry your ID document. Strolling down a country lane (or the sidewalk in your neighborhood which is located in the middle of the biggest city in the state) does not require you to possess ID while doing so. Some folks purposely do not carry ID when OCing and not otherwise required to have ID on their person - it's called "sterile carry".
All this being said, can a LEO with an ingrown hair you know where haul you down to the station to fingerprint you and wait for a response to come back from the FBI because he says you are not telling him your true name? You bet he can! On the other hand, unless he can prove that what he wrote down on the report about the behavior(s) that led him to suspect you were not telling the truth were in fact taking place, he can also lose an unlawful arrest lawsuit. The currency involved on both sides is time and LEOs know LACs usually do not have a lot of it to spend on this silliness and even if they do they do not want to. So what they do is coerce you into doing what they want done under the possibly real threat of going down to the station to get it all sorted out.
Fortunately most LEOs see the situation as we do - a perhaps necessary encounter that they would like to conclude as quickly and painlessly as possible. Which is why it is usually better to slowly and deliberately transition from DEFCON 1 to DEFCON Eleventy!!!!11!! as needed, as opposed to doing it all at once as soon as the cop comes into sight.