Page 1 of 2 12 LastLast
Results 1 to 15 of 28

Thread: Particle birth from WeightMap

  1. #1
    Registered User
    Join Date
    Jun 2014
    Location
    Right here
    Posts
    1,535

    Particle birth from WeightMap

    Is there a way to emit particles from a WeightMap?

    I can add a procedural texture with nodes for the particle birth rate. When I add a WeightMap node and connect it to the value it doesn't work.

    Any idea how to do this in LW?

  2. #2
    I don't recall ever getting weight maps to work with particles properly. I've always just used image maps on uved objects.

    Click image for larger version. 

Name:	TestParticles.png 
Views:	32 
Size:	36.4 KB 
ID:	145746

    It would be nice if we could use weight maps for particles though, given you can paint weight maps in layout natively now.
    Professional-level 3d training: Ryan's Lightwave Learning
    Plugin Developer: RR Tools for Lightwave

  3. #3
    Registered User
    Join Date
    Jun 2014
    Location
    Right here
    Posts
    1,535
    Quote Originally Posted by Ryan Roye View Post
    I don't recall ever getting weight maps to work with particles properly. I've always just used image maps on uved objects.

    Click image for larger version. 

Name:	TestParticles.png 
Views:	32 
Size:	36.4 KB 
ID:	145746

    It would be nice if we could use weight maps for particles though, given you can paint weight maps in layout natively now.
    Thank you Ryan. Yes that's exactly why I'm asking. I'd like to use 3rd Powers PaintWeights to control particle emission (as it works for instances). Still, I think maybe there's a way with nodes to convert the weight map into a greyscale image that can be used.

  4. #4
    RETROGRADER prometheus's Avatar
    Join Date
    Aug 2003
    Location
    sweden stockholm
    Posts
    15,119
    I think Bryphi77 actually managed to do that in a tutorial he had up on youtube..then he took a lot of them down and including that I think, but he managed through nodel wizardy to get particles to spawn from weightmaps.

  5. #5
    Super Member Chris S. (Fez)'s Avatar
    Join Date
    Feb 2003
    Location
    Virginia
    Posts
    2,955
    Quote Originally Posted by prometheus View Post
    I think Bryphi77 actually managed to do that in a tutorial he had up on youtube..then he took a lot of them down and including that I think, but he managed through nodel wizardy to get particles to spawn from weightmaps.
    This should not take wizardy. This should be insanely straightforward.

  6. #6

    This should not take wizardy.
    sure, in a perfect world. I'm also using another app right now by the way, and nope. it ain't perfect either.

    ----------


    @ OP

    just fast, you can solve it by using a (collision object) displaced eraser object instead.

    the weight painted eraser object must be approached like this >

    Last edited by erikals; 08-12-2019 at 09:44 PM.
    LW vidz   DPont donate   LightWiki   RHiggit   IKBooster   My vidz

  7. #7

    bah, why not...   scene >
    Attached Files Attached Files
    LW vidz   DPont donate   LightWiki   RHiggit   IKBooster   My vidz

  8. #8
    Registered User
    Join Date
    Jun 2014
    Location
    Right here
    Posts
    1,535
    Quote Originally Posted by erikals View Post
    bah, why not...   scene >
    Thank you guys, will test it tonight...

    In the Particle Emitter dialog there is no direct Node button like in there is Instances. In the Particle Emitter Birth Rate shading you can select a procedural texture and select Nodes, but they don't work, only some procedural textures themselves unfortunately.

  9. #9
    Member
    Join Date
    May 2006
    Location
    France
    Posts
    4,049
    You may have a work around,

    Nearest Point node set to the mesh,
    Point Info set to the Mesh and Weight map,

    Click image for larger version. 

Name:	birthrate_weight.jpg 
Views:	37 
Size:	49.6 KB 
ID:	145749

    but approximate, because it only gives the nearest weight,
    not the averaged weight from surrounding points.

    Denis.

  10. #10
    RETROGRADER prometheus's Avatar
    Join Date
    Aug 2003
    Location
    sweden stockholm
    Posts
    15,119
    Quote Originally Posted by Chris S. (Fez) View Post
    This should not take wizardy. This should be insanely straightforward.

    True....and like this, it also works with fluids emission the same way, and of course..we should have weightpaint natively in Layout...almost a must.


  11. #11
    RETROGRADER prometheus's Avatar
    Join Date
    Aug 2003
    Location
    sweden stockholm
    Posts
    15,119
    Quote Originally Posted by dpont View Post
    You may have a work around,

    Nearest Point node set to the mesh,
    Point Info set to the Mesh and Weight map,

    Click image for larger version. 

Name:	birthrate_weight.jpg 
Views:	37 
Size:	49.6 KB 
ID:	145749

    but approximate, because it only gives the nearest weight,
    not the averaged weight from surrounding points.

    Denis.
    Thanks for the work you do..and great to see you constantly add new textures to the Rman collections, may I suggest one thing though...that would be if you add your newer plugin updates and versions in a reverse chronologic order..so the latest updates would actually be what you see first on your page..instead of having to scroll down to the end of the page.

    Iīm about to check this with particle emission.

  12. #12
    Member
    Join Date
    May 2006
    Location
    France
    Posts
    4,049
    Quote Originally Posted by prometheus View Post
    ...may I suggest one thing though...that would be if you add your newer plugin updates and versions in a reverse chronologic order..so the latest updates would actually be what you see first on your page..instead of having to scroll down to the end of the page...
    Speaking of th RmanCollect menu?
    It is in alphabetical order since a few weeks,
    may be not what you expect,
    but for retreiving a short doc for a texture.

    Denis.

  13. #13
    RETROGRADER prometheus's Avatar
    Join Date
    Aug 2003
    Location
    sweden stockholm
    Posts
    15,119
    Quote Originally Posted by dpont View Post
    You may have a work around,

    Nearest Point node set to the mesh,
    Point Info set to the Mesh and Weight map,

    Click image for larger version. 

Name:	birthrate_weight.jpg 
Views:	37 
Size:	49.6 KB 
ID:	145749

    but approximate, because it only gives the nearest weight,
    not the averaged weight from surrounding points.

    Denis.
    Thought it wasnīt working...but I figured it out I think, by using a previous layer on top of the procedural node..I got it working..perhaps a math node could be used instead to make it work as well?
    The original setup from the image by Denis did not work though.

    will post the scene later.

    Will also take a look at using metamorphic required for direct layout weight paint.

  14. #14
    RETROGRADER prometheus's Avatar
    Join Date
    Aug 2003
    Location
    sweden stockholm
    Posts
    15,119
    Quote Originally Posted by dpont View Post
    Speaking of th RmanCollect menu?
    It is in alphabetical order since a few weeks,
    may be not what you expect,
    but for retreiving a short doc for a texture.

    Denis.
    Nope...I ment the plugins added when updated, the new ones are listed at the bottom of the page, not on top of the page which would be a reverse chronological order so to speak.. wich I feel would be better.
    And thanks for the nodal setup suggestion for weight emitted particles..though I had to add some things to get it working.

  15. #15
    RETROGRADER prometheus's Avatar
    Join Date
    Aug 2003
    Location
    sweden stockholm
    Posts
    15,119
    Quote Originally Posted by Ryan Roye View Post
    I don't recall ever getting weight maps to work with particles properly. I've always just used image maps on uved objects.

    Click image for larger version. 

Name:	TestParticles.png 
Views:	32 
Size:	36.4 KB 
ID:	145746

    It would be nice if we could use weight maps for particles though, given you can paint weight maps in layout natively now.
    And yes..I got it working now..and also with metamorphic weight paint, but any painted or adjusted weightmap with metamorphic will not take affect until you change birth rate or just re-enter the same value, so it sort of restarts the calculation.

    You can also just uncheck the previous layer and re-check it again to activate it..and the particle emission should have been changed to work again...that may be more effective since you donīt have to leave metamorpic but can continue do paint adjust particle emission.

    So voila finally..both weight map paint in layout and particle emission from weight map now possible..but also with the help of Dpontīs tools..not sure you could do it otherwise..but boy the workflow, consider this workflow against what I showed in the blender video.

    2. Next challenge...get the VDB gas solver to emitt from a weight map...I know how to set the gas solver to emitt by procedural density textures, but I havenīt checked weight maps in specific.

Page 1 of 2 12 LastLast

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •