Oops, should had read your last sentence, moving on.
On Thu, Dec 5, 2013 at 8:21 AM, Daniel Brassard <[email protected]>wrote: > Is a cross product between the normal and tangent vectors not giving you > the bi-normal vector? > > > > On Wed, Dec 4, 2013 at 6:50 PM, Matt Lind <[email protected]>wrote: > >> Those calculations are for converting the normal in the normal map >> between color and euler space. The normal stored in the normal map needs a >> basis (ie: transform matrix) to act as a frame of reference so the renderer >> knows how to orient the normals in the map to the topology . That basis is >> derived from information in the Texture UV space, geometry normal, and >> Tangents and BiNormals vertex color properties. >> >> >> >> I need the algorithms for the computation of the basis, and I need to >> know how ultimapper compensates for the case when the binormals are not >> present. For example, does ultimapper assume the basis will always be >> orthogonal and do a cross product of the tangent and geometry normal to >> generate the binormal? >> >> >> >> >> >> Matt >> >> >> >> >> >> >> >> >> >> >> >> *From:* [email protected] [mailto: >> [email protected]] *On Behalf Of *francisco criado >> *Sent:* Wednesday, December 04, 2013 3:36 PM >> *To:* [email protected] >> *Subject:* Re: tangent/binormal space computation >> >> >> >> Hi Matt, >> >> will this help? >> >> >> http://softimage.wiki.softimage.com/xsidocs/tangents_binormals_SettingtheDataTypeforTangentsandBinormals.htm#Rga95703 >> >> >> >> Francisco. >> >> >> >> 2013/12/4 Matt Lind <[email protected]> >> >> I need to write a variant of ultimapper to support our proprietary >> workflows, but our content (tangent space normal maps) currently uses the >> softimage standard. I need to know the algorithms Softimage uses so I can >> make an accurate conversion to our proprietary standards. >> >> >> >> Specifically, I need to know: >> >> >> >> - how the vectors are computed in the Tangents and BiNormal vertex color >> properties >> >> - how Ultimapper does a tangent space normal transfer when only a >> Tangents vertex color property exists on the hi res mesh. >> >> (eg; what assumptions does it make / what calculations >> does it do to compensate for lack of binormals?) >> >> >> >> >> >> >> >> >> >> Matt >> >> >> > >
