Hi, I took a spin on this. But I'm not entirely sure if this usable on your scene.
I used a Tetrahedralize SOP followed by a Findshortestpath SOP to get a base poly line crawling from a start point, towards an end point. Then I tried detecting the tunnel centers nearest to the points.. It's still a bit raw on some parts, but hopefully it can be further refined
H15.5.607 Indie
Found 252 posts.
Search results Show results as topic list.
Technical Discussion » transform P and volume gradient
- galagast
- 252 posts
- Offline
Technical Discussion » Copy SOP bug?
- galagast
- 252 posts
- Offline
Okay.. looking further.. it seems to be coming from the Divide SOP's “Attribute to Swap” option.
If I simply empty the string, the error goes out.
Putting “shop_materialpath” would bring back the error.
In conclusion.. the “Attribute Swap” would transfer attributes from the Input, to the new points. The error might be saying that it cannot properly transfer the “shop_materialpath” attribute, because it is of a “String” type attribute.. one which cannot simply be interpolated to the new points created by the Compute Dual option.
If I simply empty the string, the error goes out.
Putting “shop_materialpath” would bring back the error.
In conclusion.. the “Attribute Swap” would transfer attributes from the Input, to the new points. The error might be saying that it cannot properly transfer the “shop_materialpath” attribute, because it is of a “String” type attribute.. one which cannot simply be interpolated to the new points created by the Compute Dual option.
Edited by galagast - 2016年10月12日 06:20:19
Technical Discussion » Copy SOP bug?
- galagast
- 252 posts
- Offline
I seem to be getting an error with a certain workflow on using Copy SOP with a couple of other nodes. (origin thread [sidefx.com])
Inside a Geometry node, do the ff: (repro steps)
Notes:
Inside a Geometry node, do the ff: (repro steps)
- Create a Test Geometry: Rubber Toy
- Append a PolyReduce SOP, set it to 3%.
- Append a Divide SOP, toggle ON Compute Dual
- Create a Copy SOP
- On its first input, connect a Box SOP. (Optionally reduce the size to 0.1)
- On its second input, connect the Divide SOP.
- Select the Copy SOP and enable its display flag.
- De-select the Copy SOP…
Unrecognized file type "".
Notes:
- Any of the pre-built “Test” geometries seems to exhibit this error. (Pig Head, Rubber Toy, Shader Ball, Squab)
- Tested on H14, no error.
- I tried creating a simple mesh with identical attributes (shop_materialpath, uv, N), there were no errors.
- - I also created an HDA out of the simple mesh, thinking that maybe it was because the Test geometries are HDAs.. there were still no errors. Concluding that maybe something on the Test Geometries is causing it?
Edited by galagast - 2016年10月12日 05:58:48
Houdini Indie and Apprentice » Q: copy point colors onto new geo?
- galagast
- 252 posts
- Offline
Glad to be of some help
I will post on a different thread regarding the Copy SOP error.. I looked at it again, we may be on to a bug of some sort.
I will post on a different thread regarding the Copy SOP error.. I looked at it again, we may be on to a bug of some sort.
Houdini Indie and Apprentice » Q: copy point colors onto new geo?
- galagast
- 252 posts
- Offline
Copy SOP seems to be behaving strangely.. I managed to track down the source of error. It seems to be coming from the point attribute “shop_materialpath”.. so I simply added an Attribute Delete to fix it.
I'm not particulary sure why it's causing the error though. Maybe Copy SOP does not know what to do with string attribute types?
Error:
Attached is the fixed file.
H15.5.607 Indie NC
I'm not particulary sure why it's causing the error though. Maybe Copy SOP does not know what to do with string attribute types?
Error:
Unrecognized file type "".
Attached is the fixed file.
H15.5.607 Indie NC
Houdini Indie and Apprentice » using $NPT to drive the number of scatter points
- galagast
- 252 posts
- Offline
Any chance we could have a look at the scene file? (or a simple sample scene?)
Maybe try using the detail() function instead?
Maybe try using the detail() function instead?
float detail (string, string, float) Returns the value of a detail attribute. detail(<surface_node>, <attrib_name>, <attrib_index>)
Technical Discussion » import sop points to pop
- galagast
- 252 posts
- Offline
Hi, here's another alternative solution. Using mostly attributes via wrangles.
Although I had to replace the Gravity DOP with a POP Force DOP to simulate gravity.
H15.5.607 Indie
Although I had to replace the Gravity DOP with a POP Force DOP to simulate gravity.
H15.5.607 Indie
Technical Discussion » qconvert - quaternions
- galagast
- 252 posts
- Offline
Technical Discussion » Change Particle Color based on Life (VEX)
- galagast
- 252 posts
- Offline
I might still be missing something from what you said.. my apologies.
Christopher RYes, you have to create the attribute, via Wrangles/VOPs/Attribute Create/etc…
I mean you have to create a attribute,…
Christopher RAn Attribute VOP cannot have a VOP Network inside it, unless you were referring to subnets?
…followed by a VOP network within the attribute VOP, correct ?
Christopher RYes, all of those can be written inside a single Wrangle node at SOP level. It really just depends on the workflow
I mean completely eliminating those Attribute VOPs and condensing everything from those Attribute VOPS into a wrangler node at SOP level ?
Technical Discussion » Change Particle Color based on Life (VEX)
- galagast
- 252 posts
- Offline
Christopher RYes, as mentioned on the docs link from above, there is a drop-down menu on the side of a VEXpression, choose Pass Through to see the valid paramaters for the current POP DOP.
…is there a list of parameters I can use in POP Velocity ?
Christopher RWhat do you mean by "it must be binded? Are you referring to the Data Bindings tabs?
You have to bind the Attribute VOP then you can call the Attribute within the POP Velocity but it must be binded, correct ?
If you want to call Attributes within the POP Velocity.. the attribute should first exist.
Christopher RNope. Parameters are what you see in the UI. When you hover over a parameter, it would show its name (in smallcase) and a description. That name is what you would use inside a VEXpression.
If I understand, parameters in your explanation would be using VOPS ?
Christopher RYes, it is exactly what I did on the last sample file I uploaded (H15_velocity_vexpression.hiplc [sidefx.com])
As an alternative could you use a Wrangler (AttributeWrangler /PointWrangler) at SOP level and write out what's in VOP in the Wrangler then use that in the VEX POPVelocity ?
The attributes @myNoise and @myRamp were all created in SOPs level. Then POP Velocity was able to read those.
I have attached an image which hopefully would explain the parts a bit better.
I hope this helps!
Technical Discussion » Change Particle Color based on Life (VEX)
- galagast
- 252 posts
- Offline
Upon dropping a POP velocity DOP, leaving the VEXpression empty, you can set the velocity (v) attribute for the particles directly. Overwriting any existing ones from up the chain.
So if you type in a value to the Velocity parameter like: 0, 1, 0 …particles will move up. But there's not much else you can do, like vary the speed for each particle.
That is where VEXpressions could come in. It will let you use VEX to manipulate the parameter values.
Keyword is PARAMETER values. Not ATTRIBUTE values.
In this case, it will allow you to vary or override the Velocity PARAMETER value (Not the velocity ATTRIBUTE - although after processing the VEX code, it will eventually write to the particle's velocity attribute).
I've attached a sample usage of VEXpressions in a POP Velocity. It reads in some custom attributes, and uses those to set the velocity parameter. You can also see here how you can set the color from within the VEXpression, although I don't fully recommend that method only due to the fact that it can be quite a lengthy function to type And the attribute in question (@Cd) should already exist for it to work.
Lastly, you can have a more detailed info regarding this topic by reading through it here:
https://www.sidefx.com/docs/houdini/dopparticles/vexpressions [sidefx.com]
I hope this helps
H15.5.607 Indie
So if you type in a value to the Velocity parameter like: 0, 1, 0 …particles will move up. But there's not much else you can do, like vary the speed for each particle.
That is where VEXpressions could come in. It will let you use VEX to manipulate the parameter values.
Keyword is PARAMETER values. Not ATTRIBUTE values.
In this case, it will allow you to vary or override the Velocity PARAMETER value (Not the velocity ATTRIBUTE - although after processing the VEX code, it will eventually write to the particle's velocity attribute).
I've attached a sample usage of VEXpressions in a POP Velocity. It reads in some custom attributes, and uses those to set the velocity parameter. You can also see here how you can set the color from within the VEXpression, although I don't fully recommend that method only due to the fact that it can be quite a lengthy function to type And the attribute in question (@Cd) should already exist for it to work.
Lastly, you can have a more detailed info regarding this topic by reading through it here:
https://www.sidefx.com/docs/houdini/dopparticles/vexpressions [sidefx.com]
I hope this helps
H15.5.607 Indie
Technical Discussion » Change Particle Color based on Life (VEX)
- galagast
- 252 posts
- Offline
@Christopher:
I looked at your file. The error was because you were trying to set the color (@Cd) attribute inside the POP Velocity VEXpression. If you want to set the color attribute, you will need to use POP Wrangle or POP VOP.
If you want to apply random colors, try this instead.
Anyways, I've uploaded a hip file for you to look at
@Enivob:
I found the @nage info here:
https://www.sidefx.com/docs/houdini/dopparticles/differences [sidefx.com]
I'm not sure if there are any other normalized values available in there.
I looked at your file. The error was because you were trying to set the color (@Cd) attribute inside the POP Velocity VEXpression. If you want to set the color attribute, you will need to use POP Wrangle or POP VOP.
If you want to apply random colors, try this instead.
@Cd = random(@ptnum);
Anyways, I've uploaded a hip file for you to look at
@Enivob:
I found the @nage info here:
https://www.sidefx.com/docs/houdini/dopparticles/differences [sidefx.com]
I'm not sure if there are any other normalized values available in there.
Houdini Indie and Apprentice » Q: copy point colors onto new geo?
- galagast
- 252 posts
- Offline
There is an option in the copy SOP to “Use Template Point Attributes” under the Attribute Tab..
Or, have you tried playing around with the Attribute Transfer SOP?
It would also be great if you could provide a simple scene file in-case the above didn't solve your problem
Or, have you tried playing around with the Attribute Transfer SOP?
It would also be great if you could provide a simple scene file in-case the above didn't solve your problem
Technical Discussion » How to orient dynamic wire to its driver object?
- galagast
- 252 posts
- Offline
Hi ajz3d,
I tried playing around with your file and got the gluetoanimation working without using constraint DOPs.
Although I was struggling to try and make the geometry orient itself using the Wire Deform SOP to no avail.. the Align Tangent and Attrib Normal would seem to do the trick but I could not get it to work.. It would be great if it did because it could show some natural twisting behavior.
I guess for now, we stick with the hack of rotating the geometry before deforming it.
H15.5.607 Indie
I tried playing around with your file and got the gluetoanimation working without using constraint DOPs.
Although I was struggling to try and make the geometry orient itself using the Wire Deform SOP to no avail.. the Align Tangent and Attrib Normal would seem to do the trick but I could not get it to work.. It would be great if it did because it could show some natural twisting behavior.
I guess for now, we stick with the hack of rotating the geometry before deforming it.
H15.5.607 Indie
Edited by galagast - 2016年10月10日 11:30:11
Technical Discussion » velocity overriding forces in particles?
- galagast
- 252 posts
- Offline
I also noticed (as an alternative) that you could create a POP Wrangle with this:
The POP Solver will recognize the new attributes and update @v based on the v@targetv value that you specify. The higher the @airresist, the more it will immediately move towards your target vector. I got this from opening up the POP Wind hda.
@airresist = 1; v@targetv = {0,0,1};
Technical Discussion » Change Particle Color based on Life (VEX)
- galagast
- 252 posts
- Offline
Do you have a sample file we could look at? Your first code block is missing a semi-colon “;”
You can also use (normalized age):
It is the same value you would get from
I attached a very simple sample scene.. you can also see a usage of a ramp parameter for finer control.
H15.5.607 Indie
You can also use (normalized age):
@nage
@age/@life
I attached a very simple sample scene.. you can also see a usage of a ramp parameter for finer control.
H15.5.607 Indie
Houdini Lounge » Forum: how to navigate to end of thread?
- galagast
- 252 posts
- Offline
Probably a bit late on this. I can now see “First” and “Last” links for browsing long threads.
Also to confirm, clicking the date seems to work fine on my end using iPhone and Chrome browser app.
Also to confirm, clicking the date seems to work fine on my end using iPhone and Chrome browser app.
Houdini Indie and Apprentice » Multiparm Block (list) has bug when nesting?
- galagast
- 252 posts
- Offline
Just to chime in, I would also like to be able to have re-ordering options for the multiplram list.
And I also want to have an option to specifically query the second list number (especially for parameter labels).
I'll submit an RFE now
And I also want to have an option to specifically query the second list number (especially for parameter labels).
I'll submit an RFE now
Houdini Indie and Apprentice » Render to MPLAY+FILE
- galagast
- 252 posts
- Offline
Hi Ceasar, thank you for the response. I'm quite aware of the option to manually save the image after it renders
What I was looking for was a way to have it done automatically, MPLAY render + Save.
Initially I thought that I could just enter an output path and “ip” to the Output Picture on Mantra like in the attached image, but that doesn't work I even tried using various separators like “;” “:” “|” etc..
I suppose what I was hoping for was to be able to leave Houdini rendering (locally or even on a farm), then be able to view an MPlay preview of the current render progress simultaneously, it does not even have to retain the whole sequence in memory. Sort of like enabling the Frame Buffer window in 3dsmax during rendering.
Right now, Houdini only seems to let you choose between Render to Disk or Render to MPlay.. but not both.
If this is currently impossible, I could probably send an RFE. But I just wanted to first confirm here if there was a way to actually do it.
What I was looking for was a way to have it done automatically, MPLAY render + Save.
Initially I thought that I could just enter an output path and “ip” to the Output Picture on Mantra like in the attached image, but that doesn't work I even tried using various separators like “;” “:” “|” etc..
I suppose what I was hoping for was to be able to leave Houdini rendering (locally or even on a farm), then be able to view an MPlay preview of the current render progress simultaneously, it does not even have to retain the whole sequence in memory. Sort of like enabling the Frame Buffer window in 3dsmax during rendering.
Right now, Houdini only seems to let you choose between Render to Disk or Render to MPlay.. but not both.
If this is currently impossible, I could probably send an RFE. But I just wanted to first confirm here if there was a way to actually do it.
Houdini Lounge » New Website: Post Feedback Here
- galagast
- 252 posts
- Offline
Hi, cool looking new forum!
I just have some feedback and questions regarding the changes.
And some suggestions:
I just have some feedback and questions regarding the changes.
- Is there an option to have a WYSIWYG mode when typing a new post?
- Is it possible to format a text to CODE on the same line, not on a new line?
- How do I insert an image that I've attached inside the body of a post? Currently all attachments will only appear at the bottom of the post. It would be great to be able to insert attached images in between sentences/paragraphs.
- Will there be a page or a guide on how to use the forums? Particularly, I'm looking for formatting examples that is supported by the new forums.
And some suggestions:
- I also agree, the top black bar could be thinner.
- The PREVIEW button/icon could be placed below, just beside the SUBMIT button. It doesn't even have to be an icon, it could simply be the word itself.
- +1 for the download count display on attachments.
- A minor suggestion.. remove the gray color from the smileys, and maybe replace it with white? (for contrast)
- the “list” does not seem to be showing bullets. Numbered lists works ok.
- Go to First/Last page buttons/links.
Edited by galagast - 2016年8月12日 01:51:37
-
- Quick Links