I know this is late, but I found out what causes this. I had the exact same issue. It's because the vellum rest blend is changing data on the constraints made by the pin constraints. The solution that kevin posted is probably the way you want to go. But I am attaching this example that fixes the issue/proves that the rest blend is messing up the pin constraints.

If you look at my attached hip and the photo, I limited the constraint group to only affect the distance and bend constraints (on the vellum rest blend dop node). This prevents any other constraints like the pin constraints from being affected. On the pin constraints, you can set orientation to none, that only affects hair. lower the stiffness amount. Then you will see it is now working. However, I would still use the method that kevin provided for this instance. However, the example I provided may be better in other scenarios (like the shot I am currently working on).

hope this helps someone else in the future.

tamte

evanrudefx
It's a bit odd trying to get the timing right, but I can work it out.

it's all about the values, if you look at the example, it's using chf() mostly because for me it's easier since the frame numbers are visible

the example remap curve goes from -2f to 2f
meaning that as the box1/tx value goes between -2 and 2 the sphere1/ty follows the remap curve value
so it's all about remapping values, nothing to do with the actual frames or time

Thanks. In my test I just chose some arbitrary range for my keyframes. 1-7 (just to see if I could get it working at any value). I took the translate x of the box and fit it to the range of the keyframes. So when the box made it to a value of 4 in x, the sphere will also evaluate at frame 7 which is the final frame. It definitely makes sense. Definitely more control here but definitely easier in maya. When I said timing, I more so meant remapping the ranges to get the right animation timing.

tamte

evanrudefx
But that wouldn't work with the animation editor, right?

it will, but maybe the descriptions was not clear enough, you want to drive te frame or time argument with your box tx value, not with $FF

here is an example set up as described

Image Not Found

Oh thanks! I knew I was missing something! It's a bit odd trying to get the timing right, but I can work it out.

Thanks!

tamte
you can use chf() or cht() expressions for this
use them to reference parameter holding the remapping curve
both of them have second argument where you can reference the value of a "driver", the only difference is that chf() will interpret the "driver" value as frames and cht() as seconds when sampling your remapping curve channel

Right, that makes sense. But that wouldn't work with the animation editor, right? When I select the node there is nothing in the graph editor to adjust. I just want a curve to show in the animation editor that I can adjust like with regular key framed animation.

tamte
it's for convenience
it is sort of like:

source_parm = my_parm.getReferencedParm()
source_parm.set( new_value )

it only works if you have direct reference without additional expression, also if you open Animation Editor it will show you channel of referenced parameter

it is not as elegant as instanced parameters in MAX for example, but I'm glad it's at least working like this

Thanks,

that is interesting, if I do the channel reference and add + 0 or something additional like you said then it doesn't work in reverse.

BabaJ
If you don't want the reverse connection/behaviour,
after making the reference, just right click on the parameter and select lock parameter.

Thanks. I was more so wondering why it happens.

Hello,

Someone was asking me how to do the houdini equivalent of a driven key in maya. At first I thought it could easily be done with a channel reference. In my attached gif, you can see I have a cube that is animated to move on the x axis. I copied that parameter to sphere's y axis. And now the sphere moves up as the cube moves to the right. Here is where I got stumped. He showed me in maya that you can control the interpolation of the driven key in the graph editor. I tried doing the same in houdini, but you will notice when I select the sphere it actually just shows the box's translate x parameter in the graph editor (instead of the sphere translate y). But I only want to control the curve of the "driven" parameter without affecting the source. If you reference a channel as I have done, is there anyway to control that interpolation in the animation editor? I know I could setup some way using vex and a ramp to control the interpolation, but is there a easy way to mimic a maya driven key that will allow me to adjust the result in the animation editor?

edit: I have seen lots of really old posts about this in the forum. wondering if there anything new.

Thanks

Hello,

Something that always threw me off.

1. I use a channel reference on parameter "x" to get its value from another parameter which I will call the "source".
2. changing the source value will update parameter "x"'s value. This is obviously expected.
3. changing the value on parameter "x" will update the value on the source parameter????

How is that possible? There is no expression on the source parameter, so what is causing the value to change?

johnmather
Which codec are you using? The quality slider doesn’t map to FFmpeg quality values. Each codec exposes different quality parameters. In order to simplify this, we convert the quality slider to a set of different commands for each codec.

h264 nvenc. I am pretty sure I got the same results for av1 nvenc too. Oh, that last part makes sense. I was looking in the ffmpeg documentation to try to figure out what the "quality" slider was doing. It would also be nice if you could see the command that mplay was using.

jsmack
I think quality in ffmpeg is a 2 digit number, so 100 would be truncated to 10 and produce a very low quality video. Try setting the quality to 10 and see if it produces an identical file.

wow, thanks! I tried that and they are exactly the same file size. What you said is spot on. So the best quality would actually be 99. This threw me off, I had been using ffmpeg (external) to export (which used the version I installed on my PC manually) because every time I used the built-in ffmpeg I would set the quality to 100 and get bad results. I should probably submit an RFE to limit it to 99 or something.

thanks!

Hello,
There seems to be an issue with the quality slider when exporting to a mp4 via FFmpeg in Mplay. I included a hip file, a photo, and 4 videos in the zip file. Each of the videos has the settings in the file name. The issue is that the quality slider seems inconsistent. For example, when you set the quality slider to 100, it actually exports a smaller file with bad quality compared to a value of 99 or 70. If you look at the video files, you will notice the file with quality 100 is 1.4 MB while the video at quality 99 is 5.8 MB. The video at 70 quality is 6.6 MB. I made the video have lots of particles because it exposes how poor the compression is. If you watch the video at 100 quality, by the time it gets to the end it looks quite terrible. I included a photo of the video at 100 quality (the one that looks worse) and the other photo is at 70 quality (looks better). What is going on here?
Thanks

ajz3d
I finished the tutorial a couple of weeks ago and have stumbled upon this issue too. Just like Evan, I found the solution in the docs. However, I'm stil trying to figure out how to affect color of controllers downstream. Neither color, shapecolorproperties or colornested in controldict (as suggested in the docs) have any effect on them. I wonder how it should be done properly.

{
	"control":{
		"color":[1,0,0],
		"x_min:r":0.001
	},
	"max_lock:r":[0,0,0],
	"min_lock:r":[-95.5,0,0],
	"promote":"r",
	"shape":"circle_wires",
	"shapecolor":[0.75,0.1,0.1],
	"shaperotate":[0,90,0],
	"shapescale":[1.5,1.5,1.5],
	"shapetranslate":[-0.2,0,0]
}

By the way, the tutorial was VERY helpful in helping me understand the basics of APEX. Thanks for making it, Michael.

I just tried doing the color and it didn't work for me either

goldfarb
Ah! thanks for letting us know!!
I'll update the video asap.

thanks for the rigging tutorial btw, was a lifesaver for trying to learn APEX.

Your image didn't post. Is your camera moving? Did you set the dicing camera under geometry and shading?

I found the issue. I found the solution by downloading the character switching file and comparing how it was built:

https://www.sidefx.com/contentlibrary/character-switching/ [www.sidefx.com]

in the rigging with apex tutorial when he creates the guide properties, he gives the attribute the wrong name. He puts in "parms". In the character switching file the attribute name is "properties" and not "parms".

If I update the name to be "properties" it starts working.

edit: I found in the docs where it says to use "properties" too.

Hello,

I am trying to follow the KineFX rigging with APEX training. I am on video 6 where it talks about using attribute adjust dictionary to create the point attribute that tells apex graph to promote either translation, rotation, or scale (see photo). The video adds that the dictionary attribute created will override the values that are put directly on the apex auto rig node (see photo).

https://www.sidefx.com/tutorials/kinefx-rigging-with-apex-1/ [www.sidefx.com]

However, those dictionaries don't seem to have any effect at all. I was unable to get them working on my scene, so I downloaded the tutorial files and the promoted parms seem to have no effect in the file provided from SESI either. Take a look at my video. When I select the FKautorig node, there are no controls showing in the selection sets or viewport. If the dictionary is to control these t/r/s promote groups, I would expect to see controls in the viewport (since these values are supposed to come from the dictionary), right? Once I type in "*" you can see the apex graph actually update and add the t/r/s nodes in the graph. Furthermore, if I go to the scene animate and try moving a limb then disabling the attribute dictionaries, nothing changes. Note that in the video I made a mistake because it is loading the character from disk, so disabling nodes wouldn't affect it. However I also tried connecting the scene add character node to the nodes above (and not the file node) so that it is reading the nodes above and NOT the bgeo file and I still had the same issue. Am I just not understanding something? I would appreciate any help.

Thanks

Thanks again!

freshbaked
Add a density attribute/value to your geo and it will work fine.

Thanks! That was it. Unfortunately it only seems to work with cpu (not xpu). But at least its working now. Thanks again.

ObeidaZakzak
Hello,

Karma Uniform Volume Material is a preset around Karma Pyro Shader VOP, which expects a volume with fields like density, temperature, flame and scatter.

If you want to render a mesh as a uniform volume, you need to set a Uniform Volume property, either from Karma Material Properties VOP or from a Render Geometry Settings LOP, and use a Karma Volume VOP as a material.

Did you see the docs I posted? It says its for "rendering uniform constant volumes". Also, the preset automatically sets the uniform volume property. So it was intended for geometry, not volumes.

also did you see how I got the karma pyro shader working with the geo in my video? I just had to change a few things.

The uniform volume preset is a wrapper around the karma volume (which can be used for uniform volumes)

I wonder if this is just a bug?

(thanks for the reply)

Still wondering about this : )