WLVL Posted October 26, 2015 Share Posted October 26, 2015 Hi All! 1_ I'd like to import an attribute created in SOP in the POPNET. I want to drive the particle emission rate based on this attribute. I've tried to use the point function in the constantrate parameter of the pop source. like: point( my sop node path, $PT, "myatt", 0) or point( my sop node path, $CUSTOM_ID, "myatt", 0) where custum_id is just a variable created in sop based on pt. there's something i am missing 2_how do i make the SOP attribute update every frame 3_ also i see in POPSource/Source Emission Attribute. The help doc says "When in surface mode, this point attribute will be used to vary the chance of any polygon from emitting polygons. Higher values will increase the relative chance of that polygon getting an emission." but it doesnt specify the values range. I supposed 0-1 (0-100% chance of emission). I did some test but seems to have no effect. thanks for helping! Quote Link to comment Share on other sites More sharing options...
argilop Posted October 26, 2015 Share Posted October 26, 2015 (edited) Hi, To import an attribute from SOPs to POPs, you can use a SopSOLVER in Dops. Inside the sop solver put an object merge calling your sop geometry and then with an attribute transfer you can import the attributes to pops. Hope this helps! Edited October 26, 2015 by argilop Quote Link to comment Share on other sites More sharing options...
merlino Posted October 26, 2015 Share Posted October 26, 2015 Hi WLVL, can you share your hip file? It should works simply putting the attribute in the pop source (emission attribute) Quote Link to comment Share on other sites More sharing options...
WLVL Posted October 29, 2015 Author Share Posted October 29, 2015 Hi argilop and merlino! thanks for your replies! so, i used the emission attribute in the pop source and it actually works (in the scene i was working with, it was just hard to visualize). what i'd like to know is how to use an attribute to drive a parameter in DOP. In SOP i would use a point expression, in DOP i don't know. in the attached file i created an emit_var attribute, i'd like to use it to drive the velocity variance in the POP Source. What syntax should i use to call it? thank you! SOP_att_drive_parm_in_DOP.hipnc Quote Link to comment Share on other sites More sharing options...
argilop Posted November 3, 2015 Share Posted November 3, 2015 Hey, I had a look to your file. If I understood right you want to influence with velocity variance the particles that has a value of 1 in emit_var. Basically I dived inside the POP source and multiply the variance by your attribute. SOP_att_drive_parm_in_DOP01.hipnc Quote Link to comment Share on other sites More sharing options...
fathom Posted November 3, 2015 Share Posted November 3, 2015 you can use the same expressions in dop parms as in sop parms, but just be aware of the "set initial" vs "set always" operation status. many/most dops are designed to only evaluate parms on the first frame ("set initial"). if you have something animate, you need to make sure it's set to "set always". you may have to dive into dop tool nodes to find the underlying base dop with the operation flag. Quote Link to comment Share on other sites More sharing options...
WLVL Posted November 5, 2015 Author Share Posted November 5, 2015 thank you all! argilop, that's very useful to know! is it possibile to do the exact same thing directly into the parm of the pop source node without diving inside? Quote Link to comment Share on other sites More sharing options...
argilop Posted November 9, 2015 Share Posted November 9, 2015 Well, I tried that but I had no success... If someone knows how to do that, please enlighten us! 1 Quote Link to comment Share on other sites More sharing options...
anim Posted February 22, 2016 Share Posted February 22, 2016 well, not in UI directly but if you know that any VOP network's parameter (Parameter VOP) can be overriden by attribute with the same name and type then just by looking inside of the Source POP you can see which values can be directly controlled from attributes, not many, but in case of velocity you are in luck so to control velocity variance, you can just create v@var attribute on your source (quite dangerous if you think about it as many parameters inside use very simple names, easy to override by accident) so similarly to override Velocity slider you can hunt down and find out that you can just create v@parmvel attribute on your source which will automatically override that, etc . Quote Link to comment Share on other sites More sharing options...
WLVL Posted February 22, 2016 Author Share Posted February 22, 2016 Thank you Tomas for explaining! Quote Link to comment Share on other sites More sharing options...
dyei nightmare Posted March 31, 2019 Share Posted March 31, 2019 this doesnt work in H17 Quote Link to comment Share on other sites More sharing options...
anim Posted March 31, 2019 Share Posted March 31, 2019 1 hour ago, dyei nightmare said: this doesnt work in H17 do you have an example? as far as I know attribute overrides for VOP Parameters/Binds is basis of a lot of tools, I'd be surprised if it suddenly didn't work in H17, so maybe you are trying to override something that's not a VOP Parameter? Quote Link to comment Share on other sites More sharing options...
dyei nightmare Posted March 31, 2019 Share Posted March 31, 2019 (edited) 1 hour ago, anim said: do you have an example? as far as I know attribute overrides for VOP Parameters/Binds is basis of a lot of tools, I'd be surprised if it suddenly didn't work in H17, so maybe you are trying to override something that's not a VOP Parameter? nop, but what works is doing everything in sop solver, ignoring $SF and simulation stuff vars, just doing things with $F, Edited March 31, 2019 by dyei nightmare Quote Link to comment Share on other sites More sharing options...
christophott Posted April 21, 2022 Share Posted April 21, 2022 Great post sop solver, object merge and attrib transfer did exactly what I hoped for. Although my setup was rather simple in comparison to the posts here Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.