こんにちわ。
初歩的な質問ですが透明な物体を正しくレンダリングするにはどうやればいいでしょうか?
グリッドとスフィアをデフォルトのまま原点に配置し両方にそれぞれ別のprincipal shaderをアサインし
グリッドを紫色に、スフィアの透明度を0にした場合は
紫色の板にスフィアのスペキュラが乗ったものがレンダリングされてほしいのですが
実際はスフィア部分が黒くなりそこにスペキュラが乗ったものがレンダリングされます。
スフィアの内側が黒くならないようにする方法が知りたいです。影オフ以外で。
スフィアを少し浮かせてグリッドに刺さらないように置くと黒くなりません。
mantraでレンダリングしてます。
サンプルファイルを追加しました。そのままレンダリングすれば同じような結果が出力されます。
hou19.5.640です
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日本語フォーラム » 透明な物体がめり込んでる場合のレンダリングについて
- m_a_
- 2 posts
- Online
日本語フォーラム » karmaでのボリュームのレンダリングについて
- m_a_
- 2 posts
- Online
例えばCd情報の入った閉じたジオメトリにuniform volumeをアサインしmantraでレンダリングすると
Cdの色がついたボリュームがレンダリングされますが、
これと同じことをkarmaでやるにはどうやればいいでしょうか?
karmaでrenderGeometrySettingでボリュームに設定をすればsurfaceでもボリュームとしてレンダリングされますが
Cdがついてきません。単色ならばマテリアルで設定できますがCdの色を持ってくる方法がわからないのです。
シーンファイルを追加しました。そのままレンダリングすればいいようになってます。
hou19.5.640です
Cdの色がついたボリュームがレンダリングされますが、
これと同じことをkarmaでやるにはどうやればいいでしょうか?
karmaでrenderGeometrySettingでボリュームに設定をすればsurfaceでもボリュームとしてレンダリングされますが
Cdがついてきません。単色ならばマテリアルで設定できますがCdの色を持ってくる方法がわからないのです。
シーンファイルを追加しました。そのままレンダリングすればいいようになってます。
hou19.5.640です
Edited by m_a_ - today 10:06:29
Technical Discussion » Inserting a new point at an arbitrary ptnum
- tshead2
- 30 posts
- Offline
Gang:
Curious whether there's a way to insert a point at an arbitrary location (not position in space, arbitrary ptnum) in an existing dataset?
For context, I'm working around a problem with a point cloud where what should have been point 0 is missing (I can tell this because the points in the cloud are supposed to form a regular grid). We aren't in a position to re-run the process that generated the point cloud, so I'm adding the missing point in a Wrangle and approximating its location based on its neighbors, which is good enough for now. The problem is that addpoint() appends the new point to the geometry with ptnum equal to @numpt, so I have to generate an id attribute and use Sort to get it where I want it at ptnum 0 (this matters downstream where we assign connectivity to create a surface). It's all working, but I'm curious whether there's some better way of doing it?
Thanks in advance,
Tim
Curious whether there's a way to insert a point at an arbitrary location (not position in space, arbitrary ptnum) in an existing dataset?
For context, I'm working around a problem with a point cloud where what should have been point 0 is missing (I can tell this because the points in the cloud are supposed to form a regular grid). We aren't in a position to re-run the process that generated the point cloud, so I'm adding the missing point in a Wrangle and approximating its location based on its neighbors, which is good enough for now. The problem is that addpoint() appends the new point to the geometry with ptnum equal to @numpt, so I have to generate an id attribute and use Sort to get it where I want it at ptnum 0 (this matters downstream where we assign connectivity to create a surface). It's all working, but I'm curious whether there's some better way of doing it?
Thanks in advance,
Tim
Houdini Indie and Apprentice » Trace node producing jagged edges and weird normals
- maitlandvt
- 1 posts
- Offline
Hi friend, i think i found some solutions to your problems. I just had a play around with the C.
Try Labs, remove inline points, after the trace (it's just a Facet sop, really, so you don't have to have labs, but get it anyway!!!). that is good for getting the distribution of a curve nice and even, but also low-poly (sometimes its much easier to work lowpoly, and then add back detail
then i used convert to poly and then Fuse
then i tried subdivide (with opensubdiv loop), that gave a nice smooth look, but it lost some detail of the hard edge of the C. it's different, but you might like it. (i left it bypassed, because it changes the style of your logo)
Finally, i used the quadremesh node. that will give you nice topology and get rid of your weird lighting issues from having n-gons in your geometry!
I hope that helps you get the rest of your logo looking how you want it!
~Maitland
PS (to the mod: this isn't really my first post i am also twelveplusplus/danger kitty, maybe merge, if you want/can? ty)
Try Labs, remove inline points, after the trace (it's just a Facet sop, really, so you don't have to have labs, but get it anyway!!!). that is good for getting the distribution of a curve nice and even, but also low-poly (sometimes its much easier to work lowpoly, and then add back detail
then i used convert to poly and then Fuse
then i tried subdivide (with opensubdiv loop), that gave a nice smooth look, but it lost some detail of the hard edge of the C. it's different, but you might like it. (i left it bypassed, because it changes the style of your logo)
Finally, i used the quadremesh node. that will give you nice topology and get rid of your weird lighting issues from having n-gons in your geometry!
I hope that helps you get the rest of your logo looking how you want it!
~Maitland
PS (to the mod: this isn't really my first post i am also twelveplusplus/danger kitty, maybe merge, if you want/can? ty)
Solaris and Karma » Get primvar values in parameter fields and wrangle nodes
- fbb
- 39 posts
- Offline
@mtucker - thank you for your reply. However, I must be misunderstanding something 'cause when I try formulating the "Get()" method as as you suggest. This compiles but still returns "0" instead of the correct value. Perhaps there are multiple time samples available on the input stage as you said that could break it, but I don't think so (I'm really not sure how that condition would arise, actually, but the input is pretty simple). Also, is there really no way to make this work without sampling the time?
Get(0.0)
Edited by fbb - yesterday 17:02:20
Animation » Point tranformation
- nagyviktor199017
- 1 posts
- Offline
Hello! Can anyone help me transform this form into another form without the dots going through the cube? I already have a ready pointvop and a simple solver. I would like to put this into it, but I don't know how to do it. Thank you!
Solaris and Karma » Get primvar values in parameter fields and wrangle nodes
- fbb
- 39 posts
- Offline
Figured it out, at least in the case of using it in a parameter. I had to place 'primvars:' before 'myPrimvar' in the "GetAttribute" method, like so:
I didn't need to put anything in the "Get" method.
Of course, this doesn't answer the question of how to get such attributes in a wrangle, so please chime in if you know how to do that.
Also, if anyone knows how to get a primvar without so much code and without needing to specify the object in the "GetPrimAtPath" method, so that it just uses the input geo, that would be really helpful as well.
hou.pwd().input(0).stage().GetPrimAtPath("/myObject").GetAttribute("primvars:myPrimvar").Get()
I didn't need to put anything in the "Get" method.
Of course, this doesn't answer the question of how to get such attributes in a wrangle, so please chime in if you know how to do that.
Also, if anyone knows how to get a primvar without so much code and without needing to specify the object in the "GetPrimAtPath" method, so that it just uses the input geo, that would be really helpful as well.
Solaris and Karma » Loading references via python
- oslo
- 19 posts
- Offline
Good day community
How I could load references via python LOP without inlineusd LOP ?
I want to recreate via python that USD description
def "sphere" (
prepend references = @../../home/user/sphere.usd@
)
{
}
How I could load references via python LOP without inlineusd LOP ?
I want to recreate via python that USD description
def "sphere" (
prepend references = @../../home/user/sphere.usd@
)
{
}
Solaris and Karma » Get primvar values in parameter fields and wrangle nodes
- fbb
- 39 posts
- Offline
Update: if you put "ch("primpattern")" into the "GetPrimAtPath" method, that will use whatever primitive you specify in the "Primitives" field of the node which means you can use `lopinputprims('.', 0)` in the "Primitives" field to get the geo that is plugged into the input.
Technical Discussion » I need to extrude edge loop called "contour_01"
- Aizatulin
- 474 posts
- Offline
You can also use attribute transfer node to get normals from another geometry. But as juejuezi mentioned, in fact it can be any vector attribute and VEX has many advantages doing this (creating, manipulating etc ...).
Solaris and Karma » Identifying which parm is affected by a given 'control' parm
- mtucker
- 4438 posts
- Offline
The relationship actually goes the other way... Each value parm can have a "usdcontrolparm" spare parm tag to point to the parm that should be used as the control parm. Other than that, it isn't actually the name of the parms that matters, but the relative positions of the parms... Control parms affect all value parms that follow it until the next parm that ends with "control".
日本語フォーラム » karmaでのボリュームのレンダリングについて
- Ken Taki
- 337 posts
- Offline
日本語フォーラム » 透明な物体がめり込んでる場合のレンダリングについて
- Ken Taki
- 337 posts
- Offline
Solaris and Karma » Identifying which parm is affected by a given 'control' parm
- Tim Crowson
- 237 posts
- Offline
Solaris and Karma » Get primvar values in parameter fields and wrangle nodes
- fbb
- 39 posts
- Offline
Solaris and Karma » Get primvar values in parameter fields and wrangle nodes
- Hamilton Meathouse
- 167 posts
- Offline
Here's how you'd grab an element from an array and assign it to a new primvar. You can prob use this to find a way to drive a parm I'd imagine.
vector value = usd_primvarelement(0, @primpath, "displayColor", 3); //Gets the third element in the array usd_addprimvar(0, @primpath, "myval", "vector"); usd_setprimvar(0, @primpath, "myval", value);
Houdini Indie and Apprentice » FEM and Vellum as mutual affectors?
- gordig
- 18 posts
- Offline
I found some time to try out Vellum Tet sims, and I'm having three problems with it:
I've got the whole figure fed into a Tet Conform, with a created point attribute of "targetstrength" (carried over from FEM simulations, because I'm more used to those) set to 1e9. The breasts and butt are made out of primitive spheres booled away from the base figure, Tet Embeded and given their own attribute of targetstrength, which is currently set to 0, but neither of those values seem to matter much, whether they're scaling the stretch stiffness or the compression stiffness. It doesn't help that Vellum Tet sims don't have bend stiffness.
- I can't figure out how to set the strength high enough that the figure holds its shape well enough for my liking
- Because of #1, I also can't scale the stiffness with attributes such that the only parts that deform are the ones I want to deform.
- Regardless of #1 and #2, I can't figure out how to run the animated figure through the simulation. I'm guessing I'll have to simulate the figure in base pose, then drive the simulated figure through a point deform, much like with a FEM sim.
I've got the whole figure fed into a Tet Conform, with a created point attribute of "targetstrength" (carried over from FEM simulations, because I'm more used to those) set to 1e9. The breasts and butt are made out of primitive spheres booled away from the base figure, Tet Embeded and given their own attribute of targetstrength, which is currently set to 0, but neither of those values seem to matter much, whether they're scaling the stretch stiffness or the compression stiffness. It doesn't help that Vellum Tet sims don't have bend stiffness.
Edited by gordig - yesterday 19:48:58
Houdini Indie and Apprentice » FEM and Vellum as mutual affectors?
- tamte
- 8536 posts
- Online
gordig
I found some time to try out Vellum Tet sims, and I'm having three problems with it:
- I can't figure out how to set the strength high enough that the figure holds its shape well enough for my liking
- Because of #1, I also can't scale the stiffness with attributes such that the only parts that deform are the ones I want to deform.
- Regardless of #1 and #2, I can't figure out how to run the animated figure through the simulation. I'm guessing I'll have to simulate the figure in base pose, then drive the simulated figure through a point deform, much like with a FEM sim.
1. your figure seems pretty stiff, probably more than you need so I don;t think it needs to be stiffer
2. you don't need to vary the tet stiffness to get what you are after, what you want is to add Soft Pin Constraint with Match Animation checked and let that define what parts follow the animation of target geometry with full stiffness ( areas aroud "skeleton") and which are completely free, or anything inbetween
so if you use your "targetstrength" parameter for that make is 0-1 mask as stiffness scaling parameters are applied logarithmically
3. Pin To Target Constraint with Match Animation on and control the stiffness like mentioned in 2.
to optimize the setup you can also use Hard Pin constraint for points that you want to fully follow animation (like areas around "bones") instead of having those also be very stiff soft pin constraints, however you may run into some issues and jitter if you force hard constrained points into some impossible situations
Mardini 2023 » Missing Prizes
- davidrowley
- 37 posts
- Offline
rmagee
Note: There are some people missing prizes from 2023 - please fill out this form so we can compare to our shipping lists and sort out any issues:
MISSING PRIZE CLAIM FORM [docs.google.com]
Also curious if there's an update? I'd still love to receive the 2023 prizes.
Technical Discussion » Inserting a new point at an arbitrary ptnum
- animatrix_
- 4503 posts
- Online
Hi,
Since it's the first point you can also create it by itself and them merge with the input geometry.
Since it's the first point you can also create it by itself and them merge with the input geometry.
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