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Houdini Indie and Apprentice » Houdini To Maya
- blackpixel
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Afaik you don't need to use engine if you export the RBD animation as alembic and the volumes as .vdb files. I don't know which renderer you use, but VRay and Arnold can both render .vdb files.
Houdini Learning Materials » How to get this effect?
- blackpixel
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You could actually achieve both looks in a shader with a worley noise and some fitting. The second image looks like the holes are transparent / refractive.
But that won't help you with octane + c4d so you'd have to get your hands dirty with mantra
But that won't help you with octane + c4d so you'd have to get your hands dirty with mantra
Technical Discussion » Count number of edges
- blackpixel
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nice one friedasparagus! It's a bit slower than running over prims, but still miles ahead of python
Houdini Learning Materials » Vop sop, please help
- blackpixel
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Technical Discussion » How to control the dynamic activation of the fractured pieces? HELP ME!
- blackpixel
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There are many ways to activate pieces.
In the end it's just an attribute called “active” that needs to be overridden, so the solver knows what to do with it.
This can be done inside DOPs or in SOPs.
In DOPs you can do this with a sopsolver. In SOPs you need to enable “Overwrite Attributes from SOP” on your DOP source object. If you want to animate your geometry too, then you need an attribute called “animated” : 1 = use animation, 0 = let the sim handle movement.
In the end it's just an attribute called “active” that needs to be overridden, so the solver knows what to do with it.
This can be done inside DOPs or in SOPs.
In DOPs you can do this with a sopsolver. In SOPs you need to enable “Overwrite Attributes from SOP” on your DOP source object. If you want to animate your geometry too, then you need an attribute called “animated” : 1 = use animation, 0 = let the sim handle movement.
Edited by blackpixel - June 27, 2016 03:40:30
Houdini Indie and Apprentice » Sluggish viewport Performance
- blackpixel
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Maybe you also have anti-aliasing on in the viewport ?
But honestly, I never had any good experiences with AMD cards and Houdini.
There's no need to get an overpriced titan either. Any midrange nvidia gtx will do.
I get 45fps with a ~7 million triangle mesh on my shitty GTX 660.
But honestly, I never had any good experiences with AMD cards and Houdini.
There's no need to get an overpriced titan either. Any midrange nvidia gtx will do.
I get 45fps with a ~7 million triangle mesh on my shitty GTX 660.
Houdini Learning Materials » Group SOP selection pattern
- blackpixel
- 182 posts
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Select the group sop, go to the viewport and hit the ` key to enter reselection mode.
I don't have an english keyboard, so for me it's the ^° key on the top left above TAB.
You can also reassign it in the hotkey manager. Search for “Restart Selecting”.
But I wholeheartedly agree that this node needs a visible action key next to the pattern field.
I don't have an english keyboard, so for me it's the ^° key on the top left above TAB.
You can also reassign it in the hotkey manager. Search for “Restart Selecting”.
But I wholeheartedly agree that this node needs a visible action key next to the pattern field.
Edited by blackpixel - June 24, 2016 18:32:50
Technical Discussion » Orientation from alembic file - copy SOP
- blackpixel
- 182 posts
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Your transform matrices are skewed / scaled along one axis.
Here's a workaround to get the correct orient.
Here's a workaround to get the correct orient.
Edited by blackpixel - June 24, 2016 18:08:58
Technical Discussion » Count number of edges
- blackpixel
- 182 posts
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Konstantin Magnus
Not very elegant, but you could set carve node to
U = 0 and V = 1
Breakpoints -> Cut Breakpoints
and count prims.
Doesn't carve return multiple lines along shared edges ? That would give you a wrong number.
Technical Discussion » Count number of edges
- blackpixel
- 182 posts
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Python is indeed very slow when you have to deal with millions of polygons.
But there is another way using vex
You run an attrib wrangle over primitives and for each primitive you look at its half edges.
hedge_equivcount() will give you the number of half edges that are equivalent to your current half edge.
If it has only one equivalent, then it's an unshared edge.
If it has more, then you know it's a shared edge and it contributes by ( 1 / hedge_equivcount ) to the total count.
An edge between two primitives thus equals 1, because each prim's half edge contributes 0.5.
Last but not least you promote the count to a detail attribute to get the total sum.
This might sound more complicated, but it is faster because most of it is running multithreaded in the wrangle sop.
But there is another way using vex
You run an attrib wrangle over primitives and for each primitive you look at its half edges.
hedge_equivcount() will give you the number of half edges that are equivalent to your current half edge.
If it has only one equivalent, then it's an unshared edge.
If it has more, then you know it's a shared edge and it contributes by ( 1 / hedge_equivcount ) to the total count.
An edge between two primitives thus equals 1, because each prim's half edge contributes 0.5.
Last but not least you promote the count to a detail attribute to get the total sum.
This might sound more complicated, but it is faster because most of it is running multithreaded in the wrangle sop.
Edited by blackpixel - June 24, 2016 17:11:32
Houdini Learning Materials » simple alpha question
- blackpixel
- 182 posts
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You have this in Set:
*,^v,^Alpha , which means : All ( * ), except v ( ^v ), except Alpha ( ^Alpha )
Alpha is in Multiply, so it gets multiplied with the same attribute on your box, but your box has no Alpha attribute, so Alpha * 0 = 0.
2 solutions:
Change Set to “Alpha” or whatever attributes you want to take over,
or give the box am Alpha attribute with a value of 1.0.
*,^v,^Alpha , which means : All ( * ), except v ( ^v ), except Alpha ( ^Alpha )
Alpha is in Multiply, so it gets multiplied with the same attribute on your box, but your box has no Alpha attribute, so Alpha * 0 = 0.
2 solutions:
Change Set to “Alpha” or whatever attributes you want to take over,
or give the box am Alpha attribute with a value of 1.0.
Technical Discussion » how to control density range without Attribute Bias
- blackpixel
- 182 posts
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What this bias essentially is, is a blend between your attribute and 1.0.
So you can easily build your own bias with a wrangle or point VOP
You are also not limited to Cd and it's a good practice to use your custom attribute to do what you want.
There are some nodes that override color and it might get you in trouble at some point.
And in the case of the density attribute: you just need a float, so there is no need to store a vector.
You can always preview any attribute with a visualizer or a Color SOP ( ramp from attribute )
So you can easily build your own bias with a wrangle or point VOP
You are also not limited to Cd and it's a good practice to use your custom attribute to do what you want.
There are some nodes that override color and it might get you in trouble at some point.
And in the case of the density attribute: you just need a float, so there is no need to store a vector.
You can always preview any attribute with a visualizer or a Color SOP ( ramp from attribute )
Edited by blackpixel - June 24, 2016 09:09:02
Houdini Indie and Apprentice » Parameter Spreadsheet for selected nodes
- blackpixel
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You could just write Bone_Tweaks, but that would give you all of them, not just the selected ones.
If you want to change those parameters more than once, then a bundle really is the way to go.
Here's a little python snippet, that lets you create a bundle from the selected nodes, but it extends the node path to the sub level node you want:
Create a new tool and paste this into the script tab -> select your nodes -> run the tool
If you want to change those parameters more than once, then a bundle really is the way to go.
Here's a little python snippet, that lets you create a bundle from the selected nodes, but it extends the node path to the sub level node you want:
input = hou.ui.readMultiInput("Create Sublevel Bundle" + 30*" ",
("Bundle Name:", "Sublevel Node Name:"),
initial_contents=("bundle1","Bone_Tweaks"),
buttons=("Create Bundle", "Cancel"),
close_choice=1)
if input[0] == 0:
bundle = hou.nodeBundle(input[1][0])
if bundle in hou.nodeBundles():
bundle.clear()
else:
bundle = hou.addNodeBundle(input[1][0])
for node in hou.selectedNodes():
sub_node = hou.node(node.path() + "/" + input[1][1])
bundle.addNode(sub_node)
Create a new tool and paste this into the script tab -> select your nodes -> run the tool
Houdini Indie and Apprentice » alembic import. where is point data?
- blackpixel
- 182 posts
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It's probably a Packed Alembic primitive when you load it ( with default settings ).
Simply unpack it with the Unpack SOP and you can access all the geometry data.
Simply unpack it with the Unpack SOP and you can access all the geometry data.
Houdini Indie and Apprentice » Parameter Spreadsheet for selected nodes
- blackpixel
- 182 posts
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You can create a new bundle by dragging the selected nodes into the Bundle List pane. Then you can select the bundle in the OP Mask chooser, or use the “arrow down” button right next to it to quick-select your bundle.
Edited by blackpixel - June 17, 2016 07:28:12
Houdini Indie and Apprentice » Update Polygons with Knife ?
- blackpixel
- 182 posts
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There is an action button right next to the group parameter where the selected polygons are listed. Click that, adjust selection and hit enter to apply.
Houdini Indie and Apprentice » Bane of my existence: Lingering small fire at center after everything has dissipated. General griping.
- blackpixel
- 182 posts
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crazyfingers
I've scoped the parameters on volume source to 0, on gas coming in. I have no idea how this little tiny fire in the middle keeps chugging along. It's there by default every time i try to make a damned smoke/ fire arrangement.
If you provide a hip file, then it's much easier to help you.
crazyfingers
There's so many little knobs and inputs that you tweak and they do absolutely nothing. I've never been driven so insane by a piece of software in my entire life. Every important element you need to tweak is terribly named, has no documentation on its tool tip (the less important it is, the more likely it is to be tool tipped), is scattered into some corner of the node tree, and in no way has any indication of being important.
Every node has a help card, with a detailed explanation of all its parameters and tips on how to use it. Just click on the question mark in the upper right corner of the Parameters Pane
crazyfingers
Would it kill you guys to create a sticky of worthwhile resources to learn this forsaken software, considering how impossibly hard it is to ask 1 question at a time to become competent with this thing?
The capabilities of Houdini are amazing for particles, the actual workflow and setup of the system is maddening, documentation and resources to pick it up are abysmal.
Did you take a look at the tutorials listed here ?
http://www.sidefx.com/learning-paths/ [sidefx.com]
Technical Discussion » Noob Shader share question
- blackpixel
- 182 posts
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Houdini Learning Materials » Particle Flock Systems for birds?
- blackpixel
- 182 posts
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Look at the POP Steer DOP nodes
E.g. POP Steer Seek will make them follow targets from SOP context.
E.g. POP Steer Seek will make them follow targets from SOP context.
Houdini Indie and Apprentice » Normalising Rotations for Procedral Modeling
- blackpixel
- 182 posts
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if you want to cover the original triangle, then you need to take skewing into account too. A simpler way to do this would be to get half of the vector from point0 to point1 and use it as an offset position from point2. Then create the new primitive from point0, point1, point3 (new), point4 (new).
Edited by blackpixel - June 3, 2016 01:33:35
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