>From my small experience about this, you can't make a custom topology or kinematics "node", you make a node that abstract the more or less complex computation, then you feed the topology nodes (or a matrix in the case of kinematics). As you stated you can't use locators, or location queries in a custom ice node, so if you need them the workflow is to break you ice node in smaller parts.
About the preformance sometimes it's faster, sometimes quite the same. I made a parallel transport frame node, the gain was only 15% but the setup faster. This node seems to perform way faster: http://shaderop.com/2011/07/cubic-bezier-curve-node-for-softimage-ice/index.html A ----------------------------------------------- Ahmidou Lyazidi Director | TD | CG artist http://vimeo.com/ahmidou/videos 2013/5/15 Matt Lind <ml...@carbinestudios.com> > well, let's answer the questions first: > > 1) Does anybody have source code they are willing to share for custom ICE > Nodes that deal with topology and/or geometry? > > 2) Does the lack of reference, location, and execute ports for custom ICE > nodes mean I cannot cast a location search from inside an ICE node? > > > > To answer your question: > > Imagine two nulls and two NURBS Surfaces. the task is to find the nearest > location from the first null to the first surface. At that location, build > an orthonormal basis and compute the local transform of the null relative > to that basis. Then reconstruct that relationship by applying it to the > 2nd null relative to the 2nd surface assuming both surfaces use uniform > parameterization, not non-uniform as is the softimage default. Version 2: > extend to operate on vertices of polygon meshes instead of nulls. I have a > working version, but it is slow and not very stable. > > The problem I'm encountering is it simply takes too many factory nodes to > be able to work efficiently. Each node has a certain amount of overhead > regardless of what it does. Plus, the support for NURBS in ICE is rather > abysmal. I have to construct my own orthonormal basis plus implement my own > algorithm to convert from non-uniform parameterization to uniform > parameterization. Both are doable, but take very many nodes to do it > (including support for edge cases) making the whole effort rather clumsy at > best. The parameterization conversion is expensive as it involves sorting > and searching (while/repeat/counter nodes). When applying the ICE Compound > to a polygon mesh with 5,000+ vertices.....it gets the job done, but > chugs. > > I have a version of this tool written as a scripted operator, and it > performs really well because it has better SDK support and the > sorting/searching can be better optimized. But one shortcoming of scripted > operators is they self-delete if an input goes missing (which often happens > on scene load or model import when the content has been modifed > externally). This in turn causes content using the operator to malfunction > generating bug reports which are sent to artists to fix. Unfortunately > most artists weren't around when the content was created years ago, so they > have no idea what's wrong, what the expected output is supposed to look > like, or how to fix it. Often an asset has to be retired and replaced. > This is my motivation for rewriting the tool as a custom ICE node as ICE is > much more graceful when it's inputs don't exist - it just turns red and > sits patiently until conditions improve. This gives artists a chance to > fix the problem without having to sweat the details because they can read > the GetData node to see what's missing, then find and repair it. I'm > trying to make the content in our pipeline more durable. > > So...I'm looking for code samples of how to deal with topology and > geometry in ICE. So far I have not found any. > > > Matt > > > > > > > ------------------------------ > *From:* softimage-boun...@listproc.autodesk.com [ > softimage-boun...@listproc.autodesk.com] On Behalf Of Raffaele Fragapane [ > raffsxsil...@googlemail.com] > *Sent:* Tuesday, May 14, 2013 9:00 PM > *To:* softimage@listproc.autodesk.com > *Subject:* Re: custom ICENode - questions and request for example source > code > > Yeah, same hunch here. > Unless the performance expectations are in the multiple characters > real-time concurrently, in which case I think neither way is gonna get > there usually. > > > On Wed, May 15, 2013 at 1:04 PM, Ciaran Moloney > <moloney.cia...@gmail.com>wrote: > >> I'm sorta , kinda sure that's a dead end for a custom node. You might be >> better off optimizing your ICE tree. It doesn't sound like such a complex >> problem, care to share? >> >> >> On Wed, May 15, 2013 at 2:41 AM, Matt Lind <ml...@carbinestudios.com>wrote: >> >>> I’ve been looking at the ICE SDK as a start to the process of writing >>> custom ICE Nodes in C++. I need to write topology generators, modifiers >>> and deformation nodes. So far all the source code I’ve seen supplied with >>> Softimage only deal with particle clouds or primitive data such as >>> converting integers to scalars. Does anybody have source code for working >>> with the Softimage SDK inside an ICE Node to modify >>> topology/geometry?.....or Kinematics? Example: creating a polygon mesh >>> from scratch, adding/removing subcomponents, dealing with clusters, etc… I >>> ask this partly because the ICE SDK docs say to not use the object >>> model….which leads to the question – how do I do anything?**** >>> >>> **** >>> >>> **** >>> >>> **** >>> >>> **** >>> >>> While also browsing the SDK docs, I saw in the ‘limitations’ section >>> that custom ICE Nodes cannot define reference, location, or execute >>> ports. Since I am very interested in working with locations, does this >>> mean I cannot do queries for locations from inside the ICE Node? Or does >>> it only mean I cannot send/receive locations from other ICE nodes?**** >>> >>> **** >>> >>> Example:**** >>> >>> **** >>> >>> I need to write an ICE Node which takes a polygon mesh and 2 NURBS >>> Surfaces as inputs, and whose output is the deformation of a 2ndpolygon >>> mesh. To accomplish this feat requires the use of point Locators >>> to map the relationship between the first polygon mesh’s points relative to >>> the first surface, then re-interpret that information to deform the points >>> of the 2nd polygon mesh in relation to the 2nd surface. You can assume >>> the two polygon meshes and two surfaces have identical topology. I need to >>> write this as a custom ICE node because it is prohibitively expensive to >>> use the factory nodes (too many nodes/workarounds required leading to >>> severe performance degradation).**** >>> >>> **** >>> >>> I’d like to be able to do a point locator query from inside the custom >>> ICE node for performance (and convenience) reasons. Sample code would be a >>> big help.**** >>> >>> **** >>> >>> **** >>> >>> Anybody?**** >>> >>> **** >>> >>> **** >>> >>> Matt**** >>> >>> **** >>> >>> **** >>> >> >> > > > -- > Our users will know fear and cower before our software! Ship it! Ship it > and let them flee like the dogs they are! >
