http://www.tokeru.com/cgwiki/index.php?title=HoudiniDops#Emit_packed_prims_into_RBD_sim [www.tokeru.com] << For rigid bodies
http://www.tokeru.com/cgwiki/index.php?title=HoudiniDops#Grain_emitted_noodles [www.tokeru.com] << For noodles
For FEM / Cloth it might be a bit trickier, but I would probably just create all the copies before you sim and activate them over time.
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Houdini Lounge » Emitting DOP objects
- Solitude
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Technical Discussion » Why my point warngle intersection doesn't works?
- Solitude
- 373 posts
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I think you need a direction vector, not a position…
i@hit = intersect(1, @P, DirPoint-@P, v@NewPointLoc, NewPointUV);
I may the direction backwards – try @P-DirPoint if that doesn't work.
i@hit = intersect(1, @P, DirPoint-@P, v@NewPointLoc, NewPointUV);
I may the direction backwards – try @P-DirPoint if that doesn't work.
Technical Discussion » Apply "Inside" material in a Boolean Shatter - fracture effect
- Solitude
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Using attributes on the incoming geometry instead of relying on the groups works really well.
Houdini Learning Materials » Record Time Point Enters Group?
- Solitude
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I usually do it in a sop solver. First I create an attribute… @startFrame=10000 (large number)
then in the sop solver do what you need to evaluate whether it has entered that group or not. Often times I'll use color from an attrib transfer, then do:
if(@Cd.x>0 && @startFrame>99999){
@startFrame=min(@Frame,@startFrame);
}
If the point is ever not black or in your case is ever in that group it stores the frame and can only ever be the smaller of the values. Sops don't have a history dependence, which is why a sop solver is needed.
then in the sop solver do what you need to evaluate whether it has entered that group or not. Often times I'll use color from an attrib transfer, then do:
if(@Cd.x>0 && @startFrame>99999){
@startFrame=min(@Frame,@startFrame);
}
If the point is ever not black or in your case is ever in that group it stores the frame and can only ever be the smaller of the values. Sops don't have a history dependence, which is why a sop solver is needed.
Houdini Learning Materials » New to FX
- Solitude
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JordanR
Hey there everyone, I wasn't too sure where to post this but this seems like the best place.
I'm really interested into getting into creating particle effect stuff and I was wondering what kind of work flows you guys use? Is bringing FX from houdini to the Unreal Engine easy? What other particle software do you guys use? Also any tips on getting better in the field??
Thanks!
For generating sprites you'll need to be able to create and render nice looking fx in Houdini. Getting it into Unreal from there isn't too hard. You can render a sequence with mantra, and use the mosaic cop (compositing node) to generate a sprite sheet for use in Unreal. You can also bake out rigid bodies and export them to unreal. There are a few different scripts out there to do this.
A good video showing some of the concepts:
https://vimeo.com/164776667 [vimeo.com]
https://vimeo.com/allegrodigital [vimeo.com] < has a course here: https://www.udemy.com/game-effects-using-houdini-ue4/ [udemy.com]
Edited by Solitude - Jan. 4, 2017 01:25:52
Technical Discussion » Tab menu not allowing quick node creation, prompts interactivity in viewport instead
- Solitude
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twod
If you press TAB while in the viewport (mouse pointer over the viewport), you get the Transform tool. If you press TAB when in the network editor, you get the raw Transform SOP. I suspect that's the difference.
I thought it was pretty obvious that he is pressing tab in the network editor and it's asking him for input in the viewport (not the expected behavior). I think the issue may come from the network view being in a floating pane. I ran into this a while ago, and it took me a while to figure out the right configuration for having two windows. I've stuck with the same desktop now for a few years – I think I've kept the network editor in the main window, and instead made sure I made a floating window for the viewport instead.
Technical Discussion » Packed RBDs constraint to a deforming object
- Solitude
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I have a file here that does what you describe.
http://forums.odforce.net/topic/27511-constraint-to-deforming-static-objects/?do=findComment&comment=157969 [forums.odforce.net]
http://forums.odforce.net/topic/27511-constraint-to-deforming-static-objects/?do=findComment&comment=157969 [forums.odforce.net]
Technical Discussion » Houdini distribute effectiveness
- Solitude
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I recently did two distributed sim tests with flip and the same sim over 4 machines was 42-56% faster total sim time. I had reserved all 4 machines so nothing else would run on them, but I have no idea if they were in the same rack / same switch – that would probably help too. Memory wise it seemed as though each of the 4 machines used up about 1/2 as much memory as when I ram the full sim (not 1/4 as you would maybe expect).
Technical Discussion » Confused about array attributes
- Solitude
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As you're hinting I would agree that the creation, saving and re-loading of the attributes could be the slow part, especially if it's a large number of elements in the array. I even remember loading geo with cloth capture attrs still saved and it was pretty slow just because of the attribute size. I would guess that if your capture is not time dependent, is only the length you need (ie: only capturing 10 points instead of 100) and that if you're not recalculating anything again for the deformation, but just fetching data and setting new positions, that there isn't much you could do to speed it up. Make sure you look at the performance monitor too, and maybe try with the geometry spreadsheet closed so it doesn't have to display all the data?
Technical Discussion » Confused about array attributes
- Solitude
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You want to check out the capture pack / unpack nodes. I use them for overriding wire deform and cloth capture weights. Weights for capture use a special ‘index pair’ type that isn't directly usable in vex… so the nodes allow you to convert to regular arrays and back.
https://www.sidefx.com/docs/houdini/nodes/sop/captureattribunpack [sidefx.com]
https://www.sidefx.com/docs/houdini/nodes/sop/captureattribpack [sidefx.com]
https://www.sidefx.com/docs/houdini/nodes/sop/captureattribunpack [sidefx.com]
https://www.sidefx.com/docs/houdini/nodes/sop/captureattribpack [sidefx.com]
Edited by Solitude - Oct. 14, 2016 23:34:04
Technical Discussion » transform P and volume gradient
- Solitude
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If the polygon tube has a nice topology, ie: the same number of points around each row, you can separate it out by rows (convert sop), get the center of each row, and use that. Otherwise, you can scatter points on the outside of your geo, and then raymarch inwards until the sign of the gradient flips then tell it to stop moving and you will have your center. If you're tying to create a curve from this, you should start with an edge loop on your poly tube or something so you have a good point order to create the new curve.
Houdini Lounge » What is up with light "Exposure"?
- Solitude
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twod
Bightness is 2^Exposure, and that's what the field is showing. The buttons double or halve the brightness, which is equivalent to +1 or -1 exposure.
You just blew my mind. Or I'm going crazy. I swear I tested it and it wasn't working the way I expected it to at all. Sorry about that
I figured it out - I was typing in the matching values, not using the buttons, which I see do the right thing.
Edited by Solitude - Sept. 22, 2016 14:25:40
Houdini Lounge » Physical Camera
- Solitude
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That's fine, you could turn off those options if they were available, or keep using the standard camera. I think it'd be a great addition to have. Vray/mental ray users seem pretty keen on the use of the physical camera. Arnold also has exposure control on the camera as well as even a rolling shutter option, and also has options for modifying how the shutter opens and closes over a frame as well (with a ramp curve control).
Btw: I put in RFE: (ID# 77634): There should be a physical camera like the one in VRay
You should contact support and let them know your thoughts on the physical camera.
Btw: I put in RFE: (ID# 77634): There should be a physical camera like the one in VRay
You should contact support and let them know your thoughts on the physical camera.
Houdini Lounge » What is up with light "Exposure"?
- Solitude
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^Yes, but is it the same as exposure? The +1 on brightness certainly isn't in correlation to the +1 exposure on a light. In katana we have an f-stop hotkey that matches the light intensity, as well as in our image viewer, and also I believe the f-stop setting in nuke is the same. I could be wrong there.
Houdini Lounge » What is up with light "Exposure"?
- Solitude
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I think having it called exposure on the light makes sense. Lights have the same parameter in Renderman, and Arnold by the way. I'd rather SESI not deviate from what's more or less becoming an industry standard at this point. The idea behind it is that if you were to look at a single-light render in the image viewer then increase/decrease the exposure to find some values you liked better, you could then go back easily adjust your light exposure values to match the exposure value you liked in the image viewer – and it would match.
The problem I can see is that in Houdini there are no real exposure controls elsewhere – mplay/render view need a real exposure option to actively work like that, cops should have an exposure node, and as mentioned earlier a good physical camera like the one in vray. I'll log RFE's for that. I suggest you do the same.
The problem I can see is that in Houdini there are no real exposure controls elsewhere – mplay/render view need a real exposure option to actively work like that, cops should have an exposure node, and as mentioned earlier a good physical camera like the one in vray. I'll log RFE's for that. I suggest you do the same.
Houdini Learning Materials » How to get this effect?
- Solitude
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For quality, I would do it in a shader – I would use a volumesample of an sdf or a point cloud lookup in a shader to get the colors based on the distance.
Basically volume sample -> fit range -> ramp to drive the colors. OR a pointcloud lookup – distance to point -> fit range -> ramp.
The first image looks like more of a shader thing, the second is kind of a mix of both because they are displaced inward.
Since you're trying to do it in the asset for another package / rendering you'll need a lot of points, and can do the same thing in a sop vop/wrangle node. I would look for a way to in those apps to do the colors via shading.
Basically volume sample -> fit range -> ramp to drive the colors. OR a pointcloud lookup – distance to point -> fit range -> ramp.
The first image looks like more of a shader thing, the second is kind of a mix of both because they are displaced inward.
Since you're trying to do it in the asset for another package / rendering you'll need a lot of points, and can do the same thing in a sop vop/wrangle node. I would look for a way to in those apps to do the colors via shading.
Houdini Lounge » nodal flow diagram for Houdini?
- Solitude
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There is nothing like Katana in Houdini in the context of lighting and rendering – however I also think it could be pretty awesome to build up your renders using nodes in a similar fashion. You can currently build up render dependencies using the nodes really well… but right now you only have to use the rop's object lists and then all the settings on the rop itself… and materials are typically assigned in the object or now using material style sheets or takes. It's not a bad system, but a katana-style system for render passes would be awesome, and could totally fit Houdini well if done right.
Houdini Lounge » Inflatable Toy Licensing
- Solitude
- 373 posts
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He gave you the email address above..
skeating ‘at’ sidefx.com
at == @ (and no spaces)
He probably doesn't want to put up his email address so it doesn't get picked up by spam robots.
skeating ‘at’ sidefx.com
at == @ (and no spaces)
He probably doesn't want to put up his email address so it doesn't get picked up by spam robots.
Work in Progress » OpenCL Wrangle SOP: Geometry Manipulation on the GPU using OpenCL
- Solitude
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pusat
Gas OpenCL DOP
The only missing thing is to be able to run OpenCL on the CPU which should still be faster than C++.
I submitted an RFE for this.
http://archive.sidefx.com/docs/houdini15.0/news/13/opencl [archive.sidefx.com] << you mean this?
Houdini Lounge » Houdini as a Rendering Software for Studios
- Solitude
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Holly Showalter
Pixar use Houdini for lighting.
Where did they hear this? If they do it's most likely in a limited capacity (test renders and such, most likely for the fx guys). When I was there they used their own propriety software for lighting, and Blue Umbrella was the first short they made using Katana for the lighting package. Things could have changed by now (it's been a few years), but I don't think they switched to Houdini as their lighting package… but I could be wrong.
Method Studios used Mantra for San Andreas. Some other projects are being done fully in Matnra as far as I know, but other films there in the past were often done with Houdini / Mantra for fx stuff (volumes especially), but geometry was often sent to Maya for rendering.
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