cube example, while the corner is not sharp enough to pierce your skin, if you push your finger against it it makes a certain indentation, now keep your finger there….while I magically extend the 3 imaginary lines to infinity….ie. the cube is huge…..I guarantee you the indentation on your finger is still there..(test this on the nearest corner of a table you can find).
I can see you counter-argue with, well if you put your finger on a marble, feel the curvature, now imagine the marble is enormous……like earth…it feels flat…yet is anyone going to advocate well let's go back to the idea of a flat Earth ? The Sun is enormous to Earth….but is it any less ‘round’ ?
http://forums.odforce.net/topic/32809-measure-curvature/ [forums.odforce.net]
now get the file by petz, add a transform after switch3, scale up ie. it's bigger now…colours don't change, I rest my case.
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Houdini Indie and Apprentice » Measure Curvature
- vusta
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Houdini Indie and Apprentice » Measure Curvature
- vusta
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fuosyes…the earth is round but because it's huge (relative to humans, it's tiny to the Sun) it feels flat (but if you simply ‘zoom’ out…the earth is still same size but hey presto…doesn't look flat anymore does it?)
The definition of curvature is a ratio, therefore it's obvious that unit length will have an effect. i.e. walking on a hay bale is vastly different to walking on the earth.
But a cube, there's corners, completely flat areas and corner edges…3 distinct areas….if their curvatures magically change simply because of size…well you're just making excuses for Houdini. I like Houdini but i'm not a fanboi who refuses to see faults in Houdini, if I think it's wrong, i'll say it's wrong…..of course, there's every chance I'm wrong.
Edited by vusta - 2018年2月17日 03:54:18
Houdini Indie and Apprentice » Measure Curvature
- vusta
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tamte1) disagree…the tip of the knife is still as sharp
if you multiply curvature values by the sqrt(@area) you should get stable results
not necessarily wrong, just not very intuitive, I'm sure it has logical explanation, but personally I've never used curvature values from Measure SOP
dependence on the area may make sense if you think about it in a relative terms to the world, like how sharp something is, a knife blade is super sharp, but having 1000x scaled knife would hardly be as sharp, not sure just trying to make sense of the thinking behind
2) if you have to ‘manipulate’ the answer to get what you like…that's tantamount to cheating…and proves the orig answer was wrong in the first place….otherwise, why would you tamper with the orig answer ?
Edited by vusta - 2018年2月17日 04:10:27
Houdini Indie and Apprentice » Measure Curvature
- vusta
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to me it's plain wrong.
Let's pretend the corner of a box has curvature of 123.456
Now the box is 10 times as big, the same corner of that bigger box cannot magically has some different curvature than 123.456
Let's pretend the corner of a box has curvature of 123.456
Now the box is 10 times as big, the same corner of that bigger box cannot magically has some different curvature than 123.456
Houdini Indie and Apprentice » Measure Curvature
- vusta
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Can anyone explain what curvature means ? No I'm not being silly:
http://forums.odforce.net/topic/32809-measure-curvature/?tab=comments#comment-180324 [forums.odforce.net]
Using 16.5.378, also tested 16.0.736, same problem.
http://forums.odforce.net/topic/32809-measure-curvature/?tab=comments#comment-180324 [forums.odforce.net]
Using 16.5.378, also tested 16.0.736, same problem.
Edited by vusta - 2018年2月16日 02:12:13
Houdini Indie and Apprentice » Automatic group selection
- vusta
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i just noticed the top left corner is not quite right…but don't think a real building would have such an obtuse corner…
Houdini Indie and Apprentice » Automatic group selection
- vusta
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here…it's got most of what you're after, just use the switch at the bottom to see different groups:
- top
- bottom
- outlines
- corners
- connectors
can't be stuffed doing the hollowing out like yours….close enough.
- top
- bottom
- outlines
- corners
- connectors
can't be stuffed doing the hollowing out like yours….close enough.
Houdini Indie and Apprentice » boolean: separate polys by operations
- vusta
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Work in Progress » Tech Experiments
- vusta
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Thankyou very much for the Path Deform file, btw. With all the explainations and everything.
Houdini Indie and Apprentice » Deleting primitives based on y position
- vusta
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so instead of the usual @P.y<123, use @P.y<ch(“Threshold”) ?
very basic setup here, left method more nodes, right method in a wrangle…
very basic setup here, left method more nodes, right method in a wrangle…
Edited by vusta - 2018年2月2日 14:31:20
Houdini Indie and Apprentice » randomizing normals
- vusta
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here you are,
01) I made the font to line up from bottom, just easier to manage
02) in transform I align the ‘up’ end of the object (the L) to point to Z, this is how Houdini align things to N
(you can use the pighead to see this, the pig looks out to the front, ie. Z, so when you clone out this pighead, you'll see him looking up, using your flat grid as the emitter that is)
01) I made the font to line up from bottom, just easier to manage
02) in transform I align the ‘up’ end of the object (the L) to point to Z, this is how Houdini align things to N
(you can use the pighead to see this, the pig looks out to the front, ie. Z, so when you clone out this pighead, you'll see him looking up, using your flat grid as the emitter that is)
Edited by vusta - 2018年2月2日 00:22:49
Houdini Indie and Apprentice » Attribute transfer problem. Not very precise?
- vusta
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here's a better fix…in case you scatter alot of poins (ie. very thin strips)
The fix is, it creates a very thin prim right at the edges,eliminating the ‘elongated’ effect.
This way, you don't have to up the subdiv when you get very thin strips
The fix is, it creates a very thin prim right at the edges,eliminating the ‘elongated’ effect.
This way, you don't have to up the subdiv when you get very thin strips
Houdini Indie and Apprentice » Attribute transfer problem. Not very precise?
- vusta
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Enivobhaha, didn't i say to use subdiv Atom ?
Yet another option is to subdivide the source you are transferring from. AttributeTransfer is more accurate when it has more data to sample from.
Houdini Indie and Apprentice » Attribute transfer problem. Not very precise?
- vusta
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holy guacamole….don't mean to offend anyone here but sometimes…don't get too technical, use your common sense.
The reason the color demarcation is not clearcut is for a large prim, it doesn't take the ‘boundary’ into consideration but it uses the prim centers…so for a very long prim, you might think the color transfer should take place at the boundary but it's comparing the distance to the centroid of the prim and hence the longer prim would have the centroid further away from its target.
So knowing that, without any incredibly complicated technical procedures, I can do with ONE node.
Yeah you heard right, ONE.
All you have to do is after the randColor, add a subdiv>OpenSubdiv Bilinear. Even though Depth of 1 is enough, you might want to make it 2 or 3 to ensure accuracy.
The effect is that your prims are now not very ‘elongated’ and therefore your results are not ‘skewed’.
(also, your Distance Threshold in the attribtransfer seems too high for my liking…i usually go for 0.1 or even less for accuracy…especially now that the geo is subdivved)
The reason the color demarcation is not clearcut is for a large prim, it doesn't take the ‘boundary’ into consideration but it uses the prim centers…so for a very long prim, you might think the color transfer should take place at the boundary but it's comparing the distance to the centroid of the prim and hence the longer prim would have the centroid further away from its target.
So knowing that, without any incredibly complicated technical procedures, I can do with ONE node.
Yeah you heard right, ONE.
All you have to do is after the randColor, add a subdiv>OpenSubdiv Bilinear. Even though Depth of 1 is enough, you might want to make it 2 or 3 to ensure accuracy.
The effect is that your prims are now not very ‘elongated’ and therefore your results are not ‘skewed’.
(also, your Distance Threshold in the attribtransfer seems too high for my liking…i usually go for 0.1 or even less for accuracy…especially now that the geo is subdivved)
Edited by vusta - 2018年2月1日 16:28:43
Houdini Indie and Apprentice » Split 8 sided ngon into 2 polygons
- vusta
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Work in Progress » Carve with Random
- vusta
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if you look at the end result….12 lines…that should be roughly say 50 points all up…but look at the spreadsheet and there's over a thousand of them.
sure, stick in a fuse, simple….but fundamentally, to me it shouldn't get to the situation where you have thousands of points (piling up at starts/ends) then having to fuse them.
sure, stick in a fuse, simple….but fundamentally, to me it shouldn't get to the situation where you have thousands of points (piling up at starts/ends) then having to fuse them.
Houdini Indie and Apprentice » Polyfill: more than 1 edge loop?
- vusta
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Technical Discussion » PolyExtrude distorting topology
- vusta
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Technical Discussion » How to get a 2d slice of 3d geometry?
- vusta
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Technical Discussion » How to get a 2d slice of 3d geometry?
- vusta
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