Nerox Posted July 10, 2009 Share Posted July 10, 2009 Hi, I try to import a point attibute in a vop sop, due to create a attribute which grows on a per frame basis. I've attached a very simple example, just a grid, add a test attribute, a vop sop. In the vop sop a import attribute, a constant node, a add node and a add attribute node. If might expect the test attribute should grow over time, due to the add node, which should add (per frame) the constant to the result from the previous frame. How ever, the import attribute node seems to return 0, no matter what. This should work right? Quote Link to comment Share on other sites More sharing options...
SpencerL Posted July 10, 2009 Share Posted July 10, 2009 Hi,I try to import a point attibute in a vop sop, due to create a attribute which grows on a per frame basis. I've attached a very simple example, just a grid, add a test attribute, a vop sop. In the vop sop a import attribute, a constant node, a add node and a add attribute node. If might expect the test attribute should grow over time, due to the add node, which should add (per frame) the constant to the result from the previous frame. How ever, the import attribute node seems to return 0, no matter what. This should work right? Doesnt seem to be an attached file. But you need a feedback loop to do this. As it is now, it just re-evaluats your values every frame instead of accumulating it. There should be quite a few examples on the forum regarding feedback loops to help you out. Quote Link to comment Share on other sites More sharing options...
Nerox Posted July 13, 2009 Author Share Posted July 13, 2009 (edited) Doesnt seem to be an attached file. But you need a feedback loop to do this. As it is now, it just re-evaluats your values every frame instead of accumulating it. There should be quite a few examples on the forum regarding feedback loops to help you out. I must have been forgotten to press the upload button :s. Any way, I've uploaded it for those who are interested. A feedback loop you're saying, I'll have a look at it. vopImportAttr.hipnc Edited July 13, 2009 by Nerox Quote Link to comment Share on other sites More sharing options...
DanBode Posted July 15, 2009 Share Posted July 15, 2009 Look into the SOP Solver in DOPs for creating a feedback loop. Here is an example of that, from your file. I actually learned this from you at the H10 in New York event Spencer, so thank you very much for that. Hope this helps, Dan vopImportAttrFEEDBACK.hipnc Quote Link to comment Share on other sites More sharing options...
SpencerL Posted July 15, 2009 Share Posted July 15, 2009 Look into the SOP Solver in DOPs for creating a feedback loop. Here is an example of that, from your file. I actually learned this from you at the H10 in New York event Spencer, so thank you very much for that.Hope this helps, Dan Awesome Dan, Im glad you were able to get something from it! I wasnt sure if I was just rambling incoherint nonsense. Quote Link to comment Share on other sites More sharing options...
mrice Posted July 16, 2009 Share Posted July 16, 2009 Awesome Dan, Im glad you were able to get something from it! I wasnt sure if I was just rambling incoherint nonsense. I was there too and was playing around with feedback afterwards Another way to do it without going to dops is to proto-install the feedback sop, then you can wire that to the second input of a vop sop. Quote Link to comment Share on other sites More sharing options...
Nerox Posted July 21, 2009 Author Share Posted July 21, 2009 The Sop Solver trick works very nice, but can some one explain me what a "proto install" exactly is? I can imagine it has something to do with prototype, but how does one install this? Or is it downloadable. My apologies for my "not knowingness" ;-). Quote Link to comment Share on other sites More sharing options...
eetu Posted July 21, 2009 Share Posted July 21, 2009 The Sop Solver trick works very nice, but can some one explain me what a "proto install" exactly is? I can imagine it has something to do with prototype, but how does one install this? Or is it downloadable. In Houdini bin/ directory there is a proto_install command that can be used to install some "unsupported" operators. eetu. Quote Link to comment Share on other sites More sharing options...
Nerox Posted July 23, 2009 Author Share Posted July 23, 2009 In Houdini bin/ directory there is a proto_install command that can be used to install some "unsupported" operators. eetu. Cool, tnx. Quote Link to comment Share on other sites More sharing options...
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