Halfway down.
https://forums.unrealengine.com/showthread.php?365-Can-someone-help-me-make-a-neon-glow-material-that-affects-the-environment&highlight=houdini+engine [forums.unrealengine.com]
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Houdini Lounge » Houdini Engine for Unreal Engine 4
- AdamT
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Technical Discussion » List of connected points in python
- AdamT
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Quickest way would be to group the curve into an edgegroup and process the points for every edge.
The attached otl from an older post counts neighbouring points… look under the “## process points ###” heading.
The attached otl from an older post counts neighbouring points… look under the “## process points ###” heading.
Houdini Indie and Apprentice » How to: Forms by Akten and Quayola
- AdamT
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Houdini's not so different as people sometimes imagine; it's easy to get bogged down by all the operators and the UI, but under the surface all 3D applications do the same things. The hardest part here is that you have to think for yourself a little bit more - that's the price of flexibility: fewer canned effects. Think of Houdini as a sandbox - lots of toys, and lots of freedom to build stuff with them… but it does take perseverance and a lot of patience, and sometimes you have to unlearn old habits to learn new ones.
Sweep SOP. Mantra can also render curves: see the Next Steps foliage tutorial for grass as splines.
Segments as you'll expect them are edges in Houdini. These aren't a specific geometry type like they are in other applications. You can access them, but they're a property of primitives (a quad primitive has 4 edges, which are described as point pairs). This is a little bit outside the bare basics, so I'd suggest working on mastering small things and work your way upwards (or outwards, depending on your perspective).
The attached shows sweeps, using particles and points as sources for curves - try plugging your curve into the network.
For further reading, I'd strongly recomment going through the docs, which are pretty good (could be better) and can orient a new user to the systems and concepts of working in Houdini.
For modelling fundamentals in particular:
http://www.sidefx.com/docs/houdini12.5/model/ [sidefx.com]
Bo Ba
1. How can I dynamically run a constant length sweep nurb (c4d term) along a spline.
2. My spline has lots of segments (again, c4d term). In c4d I can iterate through the segments using xpresso, and use them as standalone splines in a loop. Can I do the same in Houdini (I don't want to break my spline into individual splines before bringing it into Houdini, since it will complicate the whole workflow, which is now C++ => C4d => Houdini.
Sweep SOP. Mantra can also render curves: see the Next Steps foliage tutorial for grass as splines.
Segments as you'll expect them are edges in Houdini. These aren't a specific geometry type like they are in other applications. You can access them, but they're a property of primitives (a quad primitive has 4 edges, which are described as point pairs). This is a little bit outside the bare basics, so I'd suggest working on mastering small things and work your way upwards (or outwards, depending on your perspective).
The attached shows sweeps, using particles and points as sources for curves - try plugging your curve into the network.
For further reading, I'd strongly recomment going through the docs, which are pretty good (could be better) and can orient a new user to the systems and concepts of working in Houdini.
For modelling fundamentals in particular:
http://www.sidefx.com/docs/houdini12.5/model/ [sidefx.com]
Houdini Indie and Apprentice » How to: Forms by Akten and Quayola
- AdamT
- 184 posts
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I think there's a certain ‘seek and ye shall find’ quality to any answer to your questions… Yes you can do all of these things, and it can come to you quite quickly if you get stuck in with the tutorials…it's a deep a bit hole and there's no one single answer; there's no shortage of info on where to start, but for creative input/discussion you could pop over to odforce.
A couple of like minded random links from there…
http://forums.odforce.net/index.php?/topic/8471-eetus-lab/ [forums.odforce.net]
http://forums.odforce.net/index.php?/topic/16470-machas-sammelsurium/ [forums.odforce.net]
The forms stuff is really cool btw.
A couple of like minded random links from there…
http://forums.odforce.net/index.php?/topic/8471-eetus-lab/ [forums.odforce.net]
http://forums.odforce.net/index.php?/topic/16470-machas-sammelsurium/ [forums.odforce.net]
The forms stuff is really cool btw.
Houdini Learning Materials » Help to modify the grass!
- AdamT
- 184 posts
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I've not seen the tutorial in question… does it use the width attribute to set the spline thickness in mantra? If so, you can drive it with a Ramp parameter to set the grass blade profile over it's U distance.
Ari Danesh covers this nicely in another grass tutorial in the official Next Steps tut series:
http://www.sidefx.com/index.php?option=com_content&task=view&id=2488&Itemid=383 [sidefx.com]
Ari Danesh covers this nicely in another grass tutorial in the official Next Steps tut series:
http://www.sidefx.com/index.php?option=com_content&task=view&id=2488&Itemid=383 [sidefx.com]
Technical Discussion » "Cut" mesh on UV wrap?
- AdamT
- 184 posts
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I gotcha, you want to dice based on UV extents of 0-1.
I expect there's a few ways to achieve this… I'd do it in python, but you can probably also do do it with VOPs, in combo with a Divide or Carve SOP.
You want to compare each primitive's edge verts/points for values that cross outside the 0-1 range (i.e. 0.9 to 1.2), mark the prims with attributes containing the U/V splicing distance, then apply the divisions per primitive with a Divide or Carve (each would require a slightly different approach…Divide probably the simplest).
Once that's done, you can seperate the points with a Fuse SOP -> Unique Points.
Then you need to iterate through all the primitives again, fixing their UVs to fit in the 0-1 domain. This may be simplest (and fast) with a Point Wrangle.
You may have to do some tidying up afterwards as, depending on what you're applying this to, you may have quite a lot of excess geometry and attributes. Also, while it should work ok for flat surfaces, it may not work on non-planar surfaces (nor non-quad prims).
(Alternatively, you could just build a new set of quads based on UV bounds)
I expect there's a few ways to achieve this… I'd do it in python, but you can probably also do do it with VOPs, in combo with a Divide or Carve SOP.
You want to compare each primitive's edge verts/points for values that cross outside the 0-1 range (i.e. 0.9 to 1.2), mark the prims with attributes containing the U/V splicing distance, then apply the divisions per primitive with a Divide or Carve (each would require a slightly different approach…Divide probably the simplest).
Once that's done, you can seperate the points with a Fuse SOP -> Unique Points.
Then you need to iterate through all the primitives again, fixing their UVs to fit in the 0-1 domain. This may be simplest (and fast) with a Point Wrangle.
You may have to do some tidying up afterwards as, depending on what you're applying this to, you may have quite a lot of excess geometry and attributes. Also, while it should work ok for flat surfaces, it may not work on non-planar surfaces (nor non-quad prims).
(Alternatively, you could just build a new set of quads based on UV bounds)
Technical Discussion » "Cut" mesh on UV wrap?
- AdamT
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I'm guessing he means to tile a portion of a tpage over neighbouring polys, I.e. needs to split the adjoining verts? ( Fuse->Unique Points )
Technical Discussion » Crashed with Nvidia OpenGL lost connection
- AdamT
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Technical Discussion » [resolved] printf in SHOPs
- AdamT
- 184 posts
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I'm digging into shaders for the first time, and seem to be having some trouble getting console output from printf in inline code.
Console output is as expected at SOP level, but in SHOPs it does nothing.
The Print node has the same behaviour, and I have the same results in H11, so am I missing something?
Edit: Fixed with a reboot.
Console output is as expected at SOP level, but in SHOPs it does nothing.
The Print node has the same behaviour, and I have the same results in H11, so am I missing something?
Edit: Fixed with a reboot.
Houdini Lounge » Houdini quotes?
- AdamT
- 184 posts
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SkybarAdamTHehe I have no idea what that means, guess I'm too new . Care to explain?
Thank you Robert for my first laugh of the week
And a good way to make someone feel old in front of those who aren't in on the pun
Don't you worry, you'll be old too before you know it
“Oh god, dad thinks he's so cool/hip…it's so embarassing!”
I suppose this is something you don't become exposed to until you hit middle age and have the opportunity to embarrass your kids. Like mums who think they know the cool acronyms, but don't, i.e. the classic:
http://textslols.com/pictures/507ccd12e3a8b7.83650834_f.jpg [textslols.com]
I guess the joke being, it's one thing to be old and hip, it's another to proclaim it on your chest
Houdini Lounge » newbie rotation question
- AdamT
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Indeed. Shame on my own late night shenanigans and brain farts: you want the Align SOP ops:
(Feed in the geometry to match, and disable Individual Alignment)
(Feed in the geometry to match, and disable Individual Alignment)
Houdini Lounge » newbie rotation question
- AdamT
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Yeah slightly trickier… How is the geo being transformed randomly? If it's through an expression or script you could pass the transform history into vector attributes, and use that to get your inverse transform later on.
The only other way I can think of off the top of my head is to group a couple of points (or 3) early on, and use those as a reference to restore the position and orientation - I'd do this in Python, I should think it can be done easily in VOPs too. Maybe store just 1 point's xyz and normal as a transform stamp…too late to experiment now though.
The only other way I can think of off the top of my head is to group a couple of points (or 3) early on, and use those as a reference to restore the position and orientation - I'd do this in Python, I should think it can be done easily in VOPs too. Maybe store just 1 point's xyz and normal as a transform stamp…too late to experiment now though.
Houdini Lounge » newbie rotation question
- AdamT
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edit: ah, scratch that. I thought it was simple, but apparently not…
I guess it's going to depend on how your geometry's been moved. If it's through transforms, you can just add them up in an xform with references, and enable Invert Transformation.
I guess it's going to depend on how your geometry's been moved. If it's through transforms, you can just add them up in an xform with references, and enable Invert Transformation.
Edited by - Sept. 9, 2013 17:40:48
Houdini Lounge » newbie rotation question
- AdamT
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Assuming your box is inside a geometry context (I.e. obj/box/), you'd use a Transform SOP node.
If you haven't already, I'd suggest playing through the First Steps tutorials as they'll save you a lot of question marks
Edit: Looking at your previous posts you seem to have covered a lot of ground already..maybe I misunderstood your question?
If you haven't already, I'd suggest playing through the First Steps tutorials as they'll save you a lot of question marks
Edit: Looking at your previous posts you seem to have covered a lot of ground already..maybe I misunderstood your question?
Edited by - Sept. 9, 2013 17:12:12
Houdini Lounge » Houdini quotes?
- AdamT
- 184 posts
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Thank you Robert for my first laugh of the week
And a good way to make someone feel old in front of those who aren't in on the pun
And a good way to make someone feel old in front of those who aren't in on the pun
Houdini Indie and Apprentice » Import large spline from C4d into Houdini
- AdamT
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I'm not a C4D user but (link) suggests you can export to illustrator, which houdini can read.
http://forums.cgsociety.org/showthread.php?t=883985 [forums.cgsociety.org]
(Assuming this is a 2d spline o/c)
http://forums.cgsociety.org/showthread.php?t=883985 [forums.cgsociety.org]
(Assuming this is a 2d spline o/c)
Houdini Indie and Apprentice » Instance question
- AdamT
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I'm only just now taking a proper look at VOPs myself, mostly in the SHOP context but they seem to be pretty much the same.
If you bear in mind that .hip files are a file system (literally), then it makes sense that you can point to nodes and pull parameters from them from anywhere in the project with the usual path expressions.
Bind and Parameter are the simplest and quickest ways to get data in.
Bind is faster, while Parameter has additional options relating to the Interface level (visibility, callbacks, menu settings, etc).
Both nodes can import attribute data, and write it out (“Use This Node to Set Parameter Attributes”).
Get Attribute can read indexed attributes from externally stored (disk) geometry…good for reading cached geo in DOPs I expect.
There's probably more, or better explanations, I'm just at the surface myself atm.
If you bear in mind that .hip files are a file system (literally), then it makes sense that you can point to nodes and pull parameters from them from anywhere in the project with the usual path expressions.
Bind and Parameter are the simplest and quickest ways to get data in.
Bind is faster, while Parameter has additional options relating to the Interface level (visibility, callbacks, menu settings, etc).
Both nodes can import attribute data, and write it out (“Use This Node to Set Parameter Attributes”).
Get Attribute can read indexed attributes from externally stored (disk) geometry…good for reading cached geo in DOPs I expect.
There's probably more, or better explanations, I'm just at the surface myself atm.
Houdini Learning Materials » script node
- AdamT
- 184 posts
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You probably want to avoid using the Script SOP as it can't modify geometry - instead use either File->New Operator Type->Python Type, or use an InlinePython SOP HDA such as:
http://www.orbolt.com/asset/animatrix::inlinePython::1.00 [orbolt.com]
If you're just diving into python for the first time, watch the Python Masterclass first…it's H11 but not much (if anything) has changed.
http://www.sidefx.com/index.php?option=com_content&task=view&id=1810&Itemid=344 [sidefx.com]
http://www.orbolt.com/asset/animatrix::inlinePython::1.00 [orbolt.com]
If you're just diving into python for the first time, watch the Python Masterclass first…it's H11 but not much (if anything) has changed.
http://www.sidefx.com/index.php?option=com_content&task=view&id=1810&Itemid=344 [sidefx.com]
Technical Discussion » some examples of attribVOP used to write attributes?
- AdamT
- 184 posts
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Use the Bind VOP for static data…
http://forums.odforce.net/index.php?/topic/17701-is-bind-export-vop-faster-to-use-than-add-attrib-vop/ [forums.odforce.net]
http://forums.odforce.net/index.php?/topic/17701-is-bind-export-vop-faster-to-use-than-add-attrib-vop/ [forums.odforce.net]
Houdini Learning Materials » ForEach node changes not passing through
- AdamT
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So glad to hear you say that; makes me feel semi-human again.
Gotta, this is the video that sorted out a lot of the cobwebs for me:
http://vimeo.com/7346925 [vimeo.com]
Gotta, this is the video that sorted out a lot of the cobwebs for me:
http://vimeo.com/7346925 [vimeo.com]
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