Thanks heaps Michael- I think the main reason is like you say at first- the normals across a flat surface are all pointing in one direction. It's ok, it was a great educational experiment, and I'm sure your gizmo will come in handy sooner or later.
Cheers, Jordan On Wed, Sep 21, 2011 at 6:00 PM, Michael Garrett <[email protected]>wrote: > Hi Jordan, > > This is the classic dilemma with spherical reflections on flat surfaces, > and it's where mirror reflections can work better. The general problem is > that the normal across the flat surface is pointing in one direction which > means too little variation when the UV coordinates are created. It will > work "correctly" but it can be a really zoomed in portion of the environment > map that is too soft, or it may look like a solid colour. One old method to > hack this in 3D is to create a slightly concave or convex surface for the > reflection pass. > > I'm not sure where the lack of detail is stemming from in your case, but > yes the camera output set to "spherical" will render the lat-long that the > gizmo expects. You could try filtering/warping the input image a bit in > order to create some variation. A "pinch" distort (inverse barrel > distortion) may help to decrease the field of view prior to the texture > lookup to pull in more detail. > > Another issue may be that your point data is in 16 bit half float which may > lack the precision needed to generate the reflection vector in some > cases, which would return a blocky looking reflection. You want full 32 bit > float. > > HTH > Michael > > > On 20 September 2011 19:31, Jordan Olson <[email protected]> wrote: > >> Hey Michael, >> >> Thanks heaps, I did some testing with it, and although it seemed to work, >> I had difficulty getting detailed reflections to show up on flat surfaces. >> Does a camera set to "spherical" shape render the appropriate lat-long image >> that the gizmo is expecting? >> >> Will do some more testing in a different scenario. Thanks heaps for the >> time you put into the gizmo, the math behind it is just beyond me. >> Cheers, >> Jordan >> >> >> On Mon, Sep 19, 2011 at 6:36 PM, Michael Garrett >> <[email protected]>wrote: >> >>> I wrote this gizmo for doing environment reflections and it does take >>> into account camera movement. Basically it does classic cg environment >>> mapping as you would have seen in a pre-raytracing Renderman shader, or the >>> Nuke Environment shader. >>> >>> To use it you need the Nuke camera, a world point AOV and world normals >>> AOV for your input, and the environment image you would generally feed it >>> would be an unwrapped spherical environment. >>> >>> There is a bit of optional exr metadata stuff that bloats this gizmo out >>> a bit, you could always remove that if you want (I need to update it some >>> time). >>> >>> Michael >>> >>> >>> >>> On 18 September 2011 21:00, Jordan Olson <[email protected]> wrote: >>> >>>> Good question, >>>> >>>> Say we have an environmental map in the form of an unwrapped image, (or >>>> a nuke 3D camera set to Sphere rather then Perspective) >>>> - and we want to apply that to the render which has a normals World >>>> pass. Though now that I think of it, it would have to take into account >>>> camera movement to draw new motion vectors... >>>> so- to answer your question, probably to simulate reflections? >>>> >>>> Ok, upon further research, I'm going to look into this method here. >>>> http://www.nukepedia.com/gizmo-downloads/other/envrelight/ >>>> The trick will be to get the reflections to take the camera movement >>>> into account... perhaps this could work if a sphere camera is attached to >>>> the animated camera. >>>> >>>> Cheers, >>>> Jordan >>>> >>>> >>>> On Mon, Sep 19, 2011 at 12:09 PM, Hugh Macdonald < >>>> [email protected]> wrote: >>>> >>>>> Do you just want to use the normals directly to map the environment, or >>>>> do you want to simulate reflections (which require a new vector being >>>>> calculated) >>>>> >>>>> Hugh Macdonald >>>>> *n**vizible** – VISUAL EFFECTS >>>>> * >>>>> [email protected] >>>>> +44(0) 20 3167 3860 >>>>> +44(0) 7773 764 708 >>>>> >>>>> www.nvizible.com >>>>> >>>>> On 18 Sep 2011, at 23:43, Jordan Olson wrote: >>>>> >>>>> Hey guys! >>>>> Would you happen to know of any ways or setups which would allow you to >>>>> remap an environment map or 3D environment onto a CG prop using the camera >>>>> normals? >>>>> Cheers, >>>>> Jordan >>>>> _______________________________________________ >>>>> Nuke-users mailing list >>>>> [email protected], http://forums.thefoundry.co.uk/ >>>>> http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-users >>>>> >>>>> >>>>> >>>>> _______________________________________________ >>>>> Nuke-users mailing list >>>>> [email protected], http://forums.thefoundry.co.uk/ >>>>> http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-users >>>>> >>>> >>>> >>>> _______________________________________________ >>>> Nuke-users mailing list >>>> [email protected], http://forums.thefoundry.co.uk/ >>>> http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-users >>>> >>> >>> >>> _______________________________________________ >>> Nuke-users mailing list >>> [email protected], http://forums.thefoundry.co.uk/ >>> http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-users >>> >> >> >> _______________________________________________ >> Nuke-users mailing list >> [email protected], http://forums.thefoundry.co.uk/ >> http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-users >> > > > _______________________________________________ > Nuke-users mailing list > [email protected], http://forums.thefoundry.co.uk/ > http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-users >
_______________________________________________ Nuke-users mailing list [email protected], http://forums.thefoundry.co.uk/ http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-users
