this looks like ray bias
most probably but not necessarily Raytracing Bias parameter on mantra, since you are saying it has no effect
what do you use for AO?
if envvight in AO mode or GI light shader then Raytracing Bias property should work, but mantra will use rendering property at the the lowest level so if the mantra setting has no effect, have a look on cam/object/material/… if there is Raytracing Bias property added
but if you are using occlusion shader, AO material, then it has it's own bias setting
but the fastest solution is always to post here your scene and spare us from guessing
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Technical Discussion » AO leak at corners
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- tamte
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Technical Discussion » Rest Position in Marble shader - H12
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- tamte
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for your case timeshift or even second input is not necessary if you keep rest sop before xform (which is doing all the deformation) but nevertheless it will not do any harm if connected
Technical Discussion » Rest Position in Marble shader - H12
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- tamte
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without seeing your file it's just a guess but
applying rest position to geometry will not help until it is applied before any deformation happens
or
if you are applying it after deformation make sure to provide rest snapshot of that geometry as Rest SOP's second input (you can just branch timeshift SOP freeze geometry on any frame you like as rest and use that for second input)
you need to be careful if your geometry is changing topology between frames though
applying rest position to geometry will not help until it is applied before any deformation happens
or
if you are applying it after deformation make sure to provide rest snapshot of that geometry as Rest SOP's second input (you can just branch timeshift SOP freeze geometry on any frame you like as rest and use that for second input)
you need to be careful if your geometry is changing topology between frames though
Houdini Indie and Apprentice » How do I render Takes sequentially?
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- tamte
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or you can use $ACTIVETAKE variable in your output path
keep take on mantra as Current
and then run your mantra with Wedge ROP with By Take option
EDIT: or maybe it's safer to use $WEDGE instead of $ACTIVETAKE since I am not sure if wedge sets the take before rendering. I never used it like that
keep take on mantra as Current
and then run your mantra with Wedge ROP with By Take option
EDIT: or maybe it's safer to use $WEDGE instead of $ACTIVETAKE since I am not sure if wedge sets the take before rendering. I never used it like that
Houdini Indie and Apprentice » moving line with a box
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- tamte
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create RBD and Wire objects through shelf (or manually)
press Attach Wire To Surface Shelf tool
follow status bar steps to complete
(in short they are
select wire, Enter
select points to attach, Enter
select rbd, Enter
select points on rbd (optional), Enter
)
it will be spring constraint by default so either tweak its stiffness or change it to Hard
press Attach Wire To Surface Shelf tool
follow status bar steps to complete
(in short they are
select wire, Enter
select points to attach, Enter
select rbd, Enter
select points on rbd (optional), Enter
)
it will be spring constraint by default so either tweak its stiffness or change it to Hard
Houdini Lounge » Two simulations interacting with each other
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- tamte
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I looked at your file and almost everything looks correct
no need for 2 sims
you have collision relationship setup Left Affects Right so you don't have to worry about coins influencing piggy if that's your intention
or if you just want them not to break the piggy just exclude them from Impact group on fractureparms
the only 2 things you need to change are
1. use Reverse SOP to invert poly normals on your piggy since they are flipped now and that's causing lot of collision problems
2. on piggy DOP Collisions/Bullet tab uncheck Polygons As Convex Hulls since it is hollow and you want it to collide properly not only as a convex hull
in order to make the break look as you want I advise you to try prebreaking it instead of using dynamic breaking, but if you find some magic setting with dynamic fracturing that looks as you want, then forget I said anything
no need for 2 sims
you have collision relationship setup Left Affects Right so you don't have to worry about coins influencing piggy if that's your intention
or if you just want them not to break the piggy just exclude them from Impact group on fractureparms
the only 2 things you need to change are
1. use Reverse SOP to invert poly normals on your piggy since they are flipped now and that's causing lot of collision problems
2. on piggy DOP Collisions/Bullet tab uncheck Polygons As Convex Hulls since it is hollow and you want it to collide properly not only as a convex hull
in order to make the break look as you want I advise you to try prebreaking it instead of using dynamic breaking, but if you find some magic setting with dynamic fracturing that looks as you want, then forget I said anything
Houdini Indie and Apprentice » How would you create a VEX Clay shader inside SHOP Network?
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- tamte
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it is better to use Clay shader from Material Palette (especially if you are using PBR)
or any shader based on new Surface Model VOP, which will use multiple importance sampling and support AOVs among other stuff and it's easier to customize since it's a VOP network
or any shader based on new Surface Model VOP, which will use multiple importance sampling and support AOVs among other stuff and it's easier to customize since it's a VOP network
Houdini Indie and Apprentice » How would you create a VEX Clay shader inside SHOP Network?
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- tamte
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it's hidden, because it is old and deprecated
if for any reason you want to use it just type this into textport
opunhide Shop v_clay
and you should now see it in shop tab menu
if for any reason you want to use it just type this into textport
opunhide Shop v_clay
and you should now see it in shop tab menu
Technical Discussion » pcopen find farthest point from sampled ones
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- tamte
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the points returned from pcopen are queued by distance so if you take the last one it will be the furthest one
to get its index you can use ( pcnumfound VOP - 1 )
then just import any attribute from it using pcimportbyidx
and don't forget to close your pcloud afterwards since you weren't iterating through all queued points
to get its index you can use ( pcnumfound VOP - 1 )
then just import any attribute from it using pcimportbyidx
and don't forget to close your pcloud afterwards since you weren't iterating through all queued points
Technical Discussion » CHOPS behavior issue
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- tamte
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instead of adding channels with Math Chop add them using Vector Chop, it can take vector mask like rx* ry* rz* and match channels according to it (each input can have differently named vectors)
when you have your rotations back in sops as an attribute containing euler values it is much faster to convert it to quaternion attribute named “orient” (which will be directly picked up by Copy Sop as rotation) than copy stamping individual XYZ components to rotation channels of transform sop
look at the file
when you have your rotations back in sops as an attribute containing euler values it is much faster to convert it to quaternion attribute named “orient” (which will be directly picked up by Copy Sop as rotation) than copy stamping individual XYZ components to rotation channels of transform sop
look at the file
Houdini Indie and Apprentice » Particle Network Difference
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- tamte
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popnetwork and popnetwork SOP is the same context, just SOP version allows you to directly connect geometry to its inputs and return result as it's output
exactly the same difference as in
dopnetwork and dopnetwork SOP
pop solver DOP uses popnetwork (internal or external) to process particles from dop sim, it has much more options about its behaviour since it is sharing dynamic environment with DOPs, but popnetwork part is the same
there is also popmerge SOP which can apply external popnetwork with different inputs and settings
btw that complexity difference in docs might have been between particle SOP and popnetwork
exactly the same difference as in
dopnetwork and dopnetwork SOP
pop solver DOP uses popnetwork (internal or external) to process particles from dop sim, it has much more options about its behaviour since it is sharing dynamic environment with DOPs, but popnetwork part is the same
there is also popmerge SOP which can apply external popnetwork with different inputs and settings
btw that complexity difference in docs might have been between particle SOP and popnetwork
Technical Discussion » Hi how to set all sub children nodes matte?
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- tamte
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I strongly recommend using Forced Matte parameter on mantra and ignore all takes and python hassle for such simple task
just type your node there like
object1
and it will be forced to render as matte
or if you want all it's children type
object1/*
you can type list of objects there, or bundle names, patterns, simply anything that will match 0-n objects
also other lists on mantra/Objects tab are very useful and essential for organizing your render passes
try not to use takes if you don't need to, keep your scene flexible and manageable
just type your node there like
object1
and it will be forced to render as matte
or if you want all it's children type
object1/*
you can type list of objects there, or bundle names, patterns, simply anything that will match 0-n objects
also other lists on mantra/Objects tab are very useful and essential for organizing your render passes
try not to use takes if you don't need to, keep your scene flexible and manageable
Technical Discussion » expresion to do 0 1 0
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- tamte
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Technical Discussion » Cloth tearing single polys
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- tamte
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you can create tearthreshold float attribute on your geometry which will be picked up by cloth object and probably multiplied with its Tear Threshold parameter
it is as well created when you click paint tearable from shelf
so just instead of painting it with Paint Sop you can vary that attribute in any way, noises, texture, whatever
similarly you can use enable tearing attribute
it is as well created when you click paint tearable from shelf
so just instead of painting it with Paint Sop you can vary that attribute in any way, noises, texture, whatever
similarly you can use enable tearing attribute
Technical Discussion » embedding string expressions
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- tamte
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something like this should work, of course depends on your node names and how you are using it
`chs(“/out/PARTICLES_start_” + padzero(3, stamp(“..”, chs(“../forstamp”), 0)) + “/sopoutput”)`
`chs(“/out/PARTICLES_start_” + padzero(3, stamp(“..”, chs(“../forstamp”), 0)) + “/sopoutput”)`
Technical Discussion » "look at" at the SOP level?
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- tamte
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cpb
is there an equivalent of the dihedral
function in vops?…
well, there is directly Look At VOP which will compute rotation matrix from given direction and up vector
be aware of Align VOP and dihedral functions for this as they don't care about up vector and therefore you may be experiencing flipping
Technical Discussion » The problem of varying specular angle in Mantra Surface
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- tamte
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it is, just don't use very low numbers since it usually produces artifacts, that's probably a bug
so for example angle varying between 0 and 10 will produce artifacts around 0
range 0.5 - 10 seems to be artifacts free
so just be careful for now
so for example angle varying between 0 and 10 will produce artifacts around 0
range 0.5 - 10 seems to be artifacts free
so just be careful for now
Houdini Lounge » ForEach Sop Applied to Points
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- tamte
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the way how For Each Sop works for Attribute values is a little tricky
it will loop through all points/primitives in order and for each attribute value it will gather all primitives/points with the same value within tolerance and process them in the same iteration
then it will merge results from all iterations as a separate geometries into one so this will change primitive/point order for all cases (except for case when you loop over individual primitives/points in original order)
it is not changing the value of the attribute though, it may seem so since it gets reordered
so what you can do is create integer attribute holding original primitive/point numbers with $PR or $PT prior to for loop and then after the loop, sort it back according to that attribute using Sort SOP
it will loop through all points/primitives in order and for each attribute value it will gather all primitives/points with the same value within tolerance and process them in the same iteration
then it will merge results from all iterations as a separate geometries into one so this will change primitive/point order for all cases (except for case when you loop over individual primitives/points in original order)
it is not changing the value of the attribute though, it may seem so since it gets reordered
so what you can do is create integer attribute holding original primitive/point numbers with $PR or $PT prior to for loop and then after the loop, sort it back according to that attribute using Sort SOP
Houdini Indie and Apprentice » VOPS Subnet breaks For loop
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- tamte
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that's only because it creates some weird combined value outputs in for node so it breaks the loop
if you rewire it back to initial position, it will be fixed again
but anyway seems like a BUG
if you rewire it back to initial position, it will be fixed again
but anyway seems like a BUG
Technical Discussion » Fresnel Displacement
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- tamte
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the position will still represent ray from camera to shading point, however “I” would represent new, bounced ray which goes from previous shading point in reflected direction
so object in reflection by using P will not necessarily have falloff to edge but rather it would be the same falloff as from camera just looking at it from different angle
so object in reflection by using P will not necessarily have falloff to edge but rather it would be the same falloff as from camera just looking at it from different angle
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