Here Im fetching Cd. But you might as well get the uv atribute from the hit and apply the color map to the scattered point.
did a example using the ray node to send several jittered rays aswell.
There are examples floating around with "complete" pathtracers done in SOPs.
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Houdini Indie and Apprentice » Reflection stored as a point attribute
- mawi
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Houdini Indie and Apprentice » Reflection stored as a point attribute
- mawi
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Do you want to store the rendered color or just fetch the Cd attribute from the object in SOPs?
First one you need to evaluate the shader and this can only be done at rendertime. In mantra you can bake shading samples to point clouds. Its a bit involved and Im not sure it works in karma.
Second option is doable with vex and some math.
1. From each point calculate a vector to camera.
2. use the reflect function/vop to calculate reflection vector
3. send a ray in that vector using intersect function/vop and look for a hit.
4. fetch Cd attribute from hit surface.
Might be able to build you a example for this later if I find time.
First one you need to evaluate the shader and this can only be done at rendertime. In mantra you can bake shading samples to point clouds. Its a bit involved and Im not sure it works in karma.
Second option is doable with vex and some math.
1. From each point calculate a vector to camera.
2. use the reflect function/vop to calculate reflection vector
3. send a ray in that vector using intersect function/vop and look for a hit.
4. fetch Cd attribute from hit surface.
Might be able to build you a example for this later if I find time.
Houdini Indie and Apprentice » Where to learn to do this honey fluid.
- mawi
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In regards to the response time from H community vs blender forums I was about to joke, -Its because houdini users got so much work to do.
Its hard to say what you got from the "I got this image" but I would start with a basic sphere as emitter for flip fluids.
Have it flow into the spoon and play with the viscous values until you got something in the ~right place.
I could be a bit tricky to get the separated drips. maybe try guide it with some curve forces or varying viscous values on the particles. You might need quite a bit of resolution.
Depending on your shot-parameters this could be a task for pop fluids maybe.
Post a .hip file on what you got, for someone to take a look at and give more detailed advice.
https://www.youtube.com/watch?v=3CxsGkLyn7U [www.youtube.com]
or maybe this one
https://www.youtube.com/watch?v=M1zVMTOCHp8 [www.youtube.com]
Welcome to Houdini.
Its hard to say what you got from the "I got this image" but I would start with a basic sphere as emitter for flip fluids.
Have it flow into the spoon and play with the viscous values until you got something in the ~right place.
I could be a bit tricky to get the separated drips. maybe try guide it with some curve forces or varying viscous values on the particles. You might need quite a bit of resolution.
Depending on your shot-parameters this could be a task for pop fluids maybe.
Post a .hip file on what you got, for someone to take a look at and give more detailed advice.
https://www.youtube.com/watch?v=3CxsGkLyn7U [www.youtube.com]
or maybe this one
https://www.youtube.com/watch?v=M1zVMTOCHp8 [www.youtube.com]
Welcome to Houdini.
Edited by mawi - Dec. 19, 2023 05:51:16
Technical Discussion » Generate sop networks from HDA callback
- mawi
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Is there a "easy" way to drag/drop a node network into a HDA, save it as code, so I can later generate it with a callback on a button?
Im looking for a functionality like the quick setups menu in the pyroburst, but I want to save the script in the HDA.
I looked in the toolutils for pyroburst, but this seems to manually create/connect node by node and I got a few to do.
Edit.
maybe I could just build them on the side, inside my HDA and write a copy/paste functionality. Easy to maintain the networks if needed.
Im looking for a functionality like the quick setups menu in the pyroburst, but I want to save the script in the HDA.
I looked in the toolutils for pyroburst, but this seems to manually create/connect node by node and I got a few to do.
Edit.
maybe I could just build them on the side, inside my HDA and write a copy/paste functionality. Easy to maintain the networks if needed.
Edited by mawi - Nov. 20, 2023 18:31:41
Technical Discussion » carving sequentially?
- mawi
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sekow
you could run vex over every prim with this neat little code snippet:#include <groom.h> float dist = chf("dist"); adjustPrimLength(0, @primnum, @perimeter, @perimeter*dist);
you need to calculate the perimeter before hand with a measure sop
fyi, a hidden gem in h20.
The carve node is updated to be able to carve by attribute.
Technical Discussion » how to best find overlapping pts on differing prims?
- mawi
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You should be able to do this with the fuse node.
1. create a s@name for each prim
2. Set it to only get unequal attributes.
3. output groups
1. create a s@name for each prim
2. Set it to only get unequal attributes.
3. output groups
Houdini Learning Materials » Animated objects in Sovler Nodes
- mawi
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Correct, the solver SOP takes the geo at first sim-frame and after that reads the processed/output geo back on each frame/time-step, like a foor loop over time.
However In the solver SOP, the nodes called input_1 -> input_4 are reading geo connected, so you can for example copy the position of your transforms onto the solved geo.
However In the solver SOP, the nodes called input_1 -> input_4 are reading geo connected, so you can for example copy the position of your transforms onto the solved geo.
Edited by mawi - Aug. 1, 2023 19:21:00
Houdini Indie and Apprentice » Vellum Fluid Sim not working with Custom Velocity
- mawi
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1. Your popadvect node is not pointing to the field/volume. Its pointing to a null where you have trailed the field. Point it at the volumerasterizeattributes2.
2. On the popadvect node there is a parm called "field name". You have typed "v vel". This parameter askes what is the name of the velocity filed you want to fetch. On the volumerasterizeattributes2 you are naming your velocity field to "v", so put only that.
2. On the popadvect node there is a parm called "field name". You have typed "v vel". This parameter askes what is the name of the velocity filed you want to fetch. On the volumerasterizeattributes2 you are naming your velocity field to "v", so put only that.
Houdini Learning Materials » How to split up grain sim
- mawi
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Im doing this sometimes yes.
You are not going to get particle<>particle interaction at the border, but often this is ok if you break up the border edge and place it smart in relation to camera.
Any node that devides your geo, clip, split,cluster points, etc etc.
1. You can build several emitters and a switch. Manually run the sims after eachother, swith emitter and change cache name.
2. Or you can go advanced and build a wedging system that will autorun your sims with different emitters.
You are not going to get particle<>particle interaction at the border, but often this is ok if you break up the border edge and place it smart in relation to camera.
Any node that devides your geo, clip, split,cluster points, etc etc.
1. You can build several emitters and a switch. Manually run the sims after eachother, swith emitter and change cache name.
2. Or you can go advanced and build a wedging system that will autorun your sims with different emitters.
Houdini Lounge » Simulation only affects points based on proximity
- mawi
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Hi. You think you could do some simple drawings or do you have some references of the effect you are looking for?
I brought in your file but I have a hard time understanding what you are trying to do.
Welcome.
I brought in your file but I have a hard time understanding what you are trying to do.
Welcome.
Houdini Indie and Apprentice » Can see Constraint, but doesn't work
- mawi
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Set them to -1(unlimited strength). If they break something in setup is incorrect and if they stay connected. The range of your strength values are to weak.
Edited by mawi - May 27, 2023 12:21:53
Houdini Indie and Apprentice » RBD Cluster help
- mawi
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Just a quick look, but seems like its working as expected.
You got one strength value for intra-cluster and one for cluster<->cluster.
What are you trying to do more specific?
You got one strength value for intra-cluster and one for cluster<->cluster.
What are you trying to do more specific?
Technical Discussion » transfer UVs by topology?
- mawi
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Technical Discussion » Sorting primitives
- mawi
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Sorry if I missunderstand.
The sort node sorts the primitive attribute order. You probably want to sort it by axis.
The spreadsheet is by default sorted by primitive number so you will not see any difference unless you have other attributes on there.
Turn on the viewport primnum display and turn the node on/off.
The sort node sorts the primitive attribute order. You probably want to sort it by axis.
The spreadsheet is by default sorted by primitive number so you will not see any difference unless you have other attributes on there.
Turn on the viewport primnum display and turn the node on/off.
Technical Discussion » How to combine a guided rbd simulation with a vellum solver?
- mawi
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Vellum and Bullet cant mutually affect each other. If you really need this then I would say go for vellum RBDs.
https://www.youtube.com/watch?v=5s8I2fs8kMs [www.youtube.com]
https://www.youtube.com/watch?v=5s8I2fs8kMs [www.youtube.com]
Technical Discussion » Breaking glue constraints RBD solver
- mawi
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This used to be a thing in the early implementations of bullet.
Seams like the Impacts only record objid and primnum for colliding object.
Had to use the sim geo to translate it into @name before passing it on to the constraints data and do the counting/deleting.
Here Im recording all collision, but you should be able to use objid to only count collisions with ex the groundplane.
*Oh, I have not seen this sop solver constraintsGeometry node. However it seams to have the same data so should be easy reconnected.
Seams like the Impacts only record objid and primnum for colliding object.
Had to use the sim geo to translate it into @name before passing it on to the constraints data and do the counting/deleting.
Here Im recording all collision, but you should be able to use objid to only count collisions with ex the groundplane.
*Oh, I have not seen this sop solver constraintsGeometry node. However it seams to have the same data so should be easy reconnected.
Edited by mawi - April 14, 2023 20:00:28
Houdini Lounge » Unintended results of self-made solver
- mawi
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Not sure what you mean with unintended, however if you are talking about the "pop" on the display grid, its because its centered in your sim and your sim is changing in size.
If you look at it from the side you wlll see.
If you look at it from the side you wlll see.
Houdini Indie and Apprentice » RBD Cluster help
- mawi
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Hey.
Maybe you already solved this but anyway.
You need to apply/paint the cluster attribute onto the geometry before going in to the cluster node.
Its a integer and negative numbers = non cluster.
Maybe you already solved this but anyway.
You need to apply/paint the cluster attribute onto the geometry before going in to the cluster node.
Its a integer and negative numbers = non cluster.
Technical Discussion » A post process question
- mawi
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If its just pushing some points on a few frames I usually use a blendshape SOP, connect the original geo and the fixed. Then key the fix on/off.
Technical Discussion » Spawning KineFX rigs - (my take / technical feedback)
- mawi
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Interesting.
Maybe do the capture before you do the copies and then manipulated the capture data. I used the capture attribute unpack but maybe there is a better way to do this all in vex.
Maybe do the capture before you do the copies and then manipulated the capture data. I used the capture attribute unpack but maybe there is a better way to do this all in vex.
Image Not Found
Edited by mawi - July 22, 2022 16:52:51
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