Wow, I shouldn't have wrote that late last night, I completely mixed things up in my previous post, sorry!
I'll try again! With a ramp, you have the source (input) values on the X axis, and the target (output) values on the Y axis. If either your source or target values aren't in the range [0, 1], you can remap them using a simple float parameter (to use as a simple multiplier if your desired lower bound is 0), or a float2 parameter to precisely control the desired range. It seems to be a standard practice in Houdini since they use it for some built-in nodes, such as the Pyro SHOP. Andy, the O(N) thing got me thinking and realized that instead of running the attrib wrangle in detail mode, which uses only a single thread, it'd be possible to generate say 4 points and, in a point wrangle, let each of these points process 1/4th of the array, thus effectively running the same logic on 4 threads! Another attrib wrangle is then needed in post to sum up the result from each point. Well, in all honesty I don't think there'll ever be a use case for it :) On 7 March 2017 at 01:14, Olivier Jeannel <[email protected]> wrote: > Ok we agree. > > > On Monday, March 6, 2017, Jonathan Moore <[email protected]> > wrote: > >> As far as I understood it Oliver, the spline version of the Houdini Ramp >> only operates in the zero to one range. You re-fit the values pre/post/ or >> both to suite your needs. >> >> >> >> I get that this doesn’t match the UX of FCurves in XSI, but I’ve always >> understood Ramp’s in Houdini to be more of a lower level discrete element >> in visual programing terms. >> >> >> >> *From:* [email protected] [mailto: >> [email protected]] *On Behalf Of *Olivier Jeannel >> *Sent:* 06 March 2017 17:31 >> *To:* Official Softimage Users Mailing List. >> https://groups.google.com/forum/#!forum/xsi_list < >> [email protected]> >> *Subject:* Re: houdini question (and where to ask) >> >> >> >> Not sure I get it Christopher (not in front of H) >> >> Does your trick actualy change the graph visualy ? >> >> In short, can I see the negative x & y values ? >> >> On Monday, March 6, 2017, Christopher Crouzet < >> [email protected]> wrote: >> >> Indeed, which is why I mentioned the “detail” mode which brings you back >> to O(N). Not saying that one approach is better than the other though, only >> that it is possible. >> >> >> >> On 7 March 2017 at 00:12, Andy Nicholas <[email protected]> wrote: >> >> Yep it is possible, but you wouldn't want to do it because each >> calculation of the maximum value would be running across N points to >> calculate that. That'd make it an O(N^2) operation, albeit spread over >> multiple threads. >> >> It might seem like a pain to have to do this in advance using an >> Attribute Promote, but by doing so, it's actually forcing you to work in a >> more efficient way. Go with it ;) >> >> >> >> On 06/03/2017 16:32, Christopher Crouzet wrote: >> >> It *is* possible to retrieve the maximum value in a VOP since nothing >> stops anyone from manually iterating through all the points of the >> geometry. This kind of operation might be more suited in “detail” mode >> though. >> >> Also, having the ramp normalized to the [0, 1] range in both the X and Y >> axis is usually “workarounded” by adding a float parameter for the >> amplitude (Y axis) that is used as a global multiplier (making later >> tweakings convenient!), and a float2 parameter for the target range (X >> axis) that is then remapped using `fit("my_ramp", 0.0, 1.0, range_min, >> range_max)` (which is also convenient for later tweakings!). >> >> Now, if you really want to have an actual FCurve, then just create a >> simple float parameter, add all the keys however you want, then query it in >> using `chf("my_param", the_time_in_seconds)` in VEX/VOP, or using the >> equivalent expression. >> >> >> >> On 6 March 2017 at 23:29, Jonathan Moore <[email protected]> >> wrote: >> >> Fabricio , >> >> >> >> The Attribute Promote help page has approx 15 examples you can load. >> Hopefully you might find something within the examples to inspires a >> solution. >> >> >> >> *From:* [email protected] [mailto: >> [email protected]] *On Behalf Of *Olivier Jeannel >> *Sent:* 06 March 2017 15:56 >> *To:* Official Softimage Users Mailing List. >> https://groups.google.com/forum/#!forum/xsi_list < >> [email protected]> >> >> >> *Subject:* Re: houdini question (and where to ask) >> >> >> >> You can't get the "get maximum in set" when inside a vop. >> >> But, you get those options with the promote attribute sop. >> >> >> >> >> On Monday, March 6, 2017, Oscar Juarez <[email protected]> wrote: >> >> I would like to be proven wrong, but that would be the way, I mean in >> your second pointvop you don't need to add another noise, your noise is >> already saved in an attribute, when you promote just check off delete >> original and you can access the same noise. Also noises have specific >> output ranges, they come in the documentation, so you can always add a fit >> node to change your range to what you need, in the geometry spreadsheet you >> can also sort by value so you can see max and min. >> >> >> >> If you press X with your mouse over the noise output it will add a >> visualization node, you can visualize on the viewport or in the geometry >> spreadsheet the values. I know its not the same but as far as I know their >> is no way to do the same as the get maximum in set node in a vopsop context. >> >> >> >> >> >> >> >> On Mon, Mar 6, 2017 at 3:57 PM, Fabricio Chamon <[email protected]> >> wrote: >> >> thanks everyone. The ramp parameter kind of works but as you say, is not >> that user friendly and does not show the points below 0. (that's ok, but I >> wonder if it is possible to write a custom widget in houdini) >> >> >> >> anyway, the thing I could not get right just yet is that sort of "get >> maximum in set" thing. Sorry for using ICE language, I'm trying to be open >> minded here, so please tell me if that`s not the correct mindset. >> >> >> >> so on this graph: >> >> >> >> [image: Imagem inline 1] >> >> >> >> ...how could I get the maximum value of the output noise node and compare >> to a single point output of the same node? >> >> >> >> From what I can tell, I'd have to: >> >> >> >> 1- create this pointvop node with a turbnoise, then store the output >> noise into an attribute (via bindexport?) >> >> 2- up one level -> drop an attrib promote (detail), set to maximum >> >> 3- drop another pointvop node with another noise node inside (same >> parameters) and compare the result noise to that found on the atrib promote >> node?? >> >> >> >> I'm 99% sure this is totally wrong...how would you go about that single >> task specifically? >> >> >> >> and finally, thanks for the suggestions on houdini forums and discord. >> will try both (although I pretty much like this list =) ) >> >> >> >> >> >> 2017-03-06 15:17 GMT+01:00 gareth bell <[email protected]>: >> >> yeah - the lack of handles is frustrating >> ------------------------------ >> >> *From:* [email protected] < >> [email protected]> on behalf of Olivier Jeannel < >> [email protected]> >> *Sent:* 06 March 2017 14:05:17 >> *To:* Official Softimage Users Mailing List. >> https://groups.google.com/forum/#!forum/xsi_list >> *Subject:* Re: houdini question (and where to ask) >> >> >> >> yep but it has no handles >> >> and try to make négative values, it takes them but wont show on the curve >> as it has a 0,1 space. >> >> Unless i'm wrong (which i'd love to be) >> >> >> >> Le 6 mars 2017 14:36, "Olivier Jeannel" <[email protected]> a >> écrit : >> >> in vop, bind and bind export node will get an set datas. >> >> Ramp Parameters is sort of fcurve. >> >> It's a bit weak in terms of curve manipulation, but does the job. >> >> It has 2 modes rgb (ramp) and spline. >> >> If you use several ramps in the same vop, name them with different name >> or they might not export. >> >> >> >> Le 6 mars 2017 14:28, "Fabricio Chamon" <[email protected]> a écrit : >> >> ..sorry, hit send too soon. >> >> >> >> Question #1: are there any equivalents to ICE "get ... in set"? or or do >> I have to iterate and store values for later comparision? In other words: >> what is the best or recommended workflow to compare single point data with >> global point data? >> >> >> >> Question #2: any nodes that resemble a fCurve node, like we have in ICE? >> if not, what is the alternative? >> >> >> >> and finally, I can see this list is becoming more and more houdini-esque >> than ever..but, what is the best place to ask beginner questions like the >> above? houdini foruns, houdini list, odForce... >> >> >> >> thanks! >> >> >> >> 2017-03-06 14:23 GMT+01:00 Fabricio Chamon <[email protected]>: >> >> Hi, I'm slowly getting into houdini and this is my first attempt to port >> a really simple ridged fractal deformer made in ICE to houdini (using >> pointvop). >> >> >> >> Question #1: are there any equivalents to ICE "get ... in set"? or or do >> I have to iterate and store values for later comparision? In other words: >> what is the best or recommended workflow to compare single point data with >> >> >> >> >> ------ >> Softimage Mailing List. >> To unsubscribe, send a mail to [email protected] >> with "unsubscribe" in the subject, and reply to confirm. >> >> >> ------ >> Softimage Mailing List. >> To unsubscribe, send a mail to [email protected] >> with "unsubscribe" in the subject, and reply to confirm. >> >> >> >> >> ------ >> Softimage Mailing List. >> To unsubscribe, send a mail to [email protected] >> with "unsubscribe" in the subject, and reply to confirm. >> >> >> >> >> ------ >> Softimage Mailing List. >> To unsubscribe, send a mail to [email protected] >> with "unsubscribe" in the subject, and reply to confirm. >> >> >> >> >> -- >> >> Christopher Crouzet >> *https://christophercrouzet.com* <https://christophercrouzet.com> >> >> >> >> >> >> ------ >> >> Softimage Mailing List. >> >> To unsubscribe, send a mail to [email protected] with >> "unsubscribe" in the subject, and reply to confirm. >> >> >> >> >> ------ >> Softimage Mailing List. >> To unsubscribe, send a mail to [email protected] >> with "unsubscribe" in the subject, and reply to confirm. >> >> >> >> >> -- >> >> Christopher Crouzet >> *https://christophercrouzet.com* <https://christophercrouzet.com> >> >> >> >> > ------ > Softimage Mailing List. > To unsubscribe, send a mail to [email protected] > with "unsubscribe" in the subject, and reply to confirm. > -- Christopher Crouzet *https://christophercrouzet.com* <https://christophercrouzet.com>
------ Softimage Mailing List. To unsubscribe, send a mail to [email protected] with "unsubscribe" in the subject, and reply to confirm.
