In the RBD Bullet Solver node's Solver tab - Collision tab, when I set Geometry Representation to a shape like Sphere and then visualize the blue collision hull by checking Show Geometry Representation in Visualize tab, it remains as a Convex Hull, not a Sphere shape.
It works if I use a DOP Network method instead. I am using Houdini 18.5, is this working in later versions, or am I missing something?
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Technical Discussion » Collision shape in RBD Bullet Solver only shows Convex Hull?
- litote
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Houdini Indie and Apprentice » scatter geo on fractured object
- litote
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I tried this method but I found that the copied objects wobble. Is there a fix? I have had to use a method with constraints instead.
Technical Discussion » Constrain objects to fractured RBD pieces?
- litote
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Technical Discussion » Constrain objects to fractured RBD pieces?
- litote
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Thank you vicvvsh so much for this! Could you please confirm if my understanding summarised below of how this works is fully correct?:
- The Attribute Randomize creates unique random values for pscale so this can be used later by the Add node to create the constraints.
- The Attribute Wrangle right under the Attribute Randomize renames the scattered points (so name: piece0_2 becomes name: sphere_0, etc), The piece_* will be associated with the fractured ground and the sphere_* will be associated with the copied objects so they can be constrained together. When these are attributes are fed in to the Merge node, the duplicated points with have the same pscale value.
- The Add node creates a polygon line (constraint) between each set of two points that share the same pscale value, i.e. overlapping duplicates. (Since the duplicate points overlap each other, the created constraint is actually just made of a representative “line”).
- The renamed points (sphere_*) are fed to the Copy to Points node so that the objects that are copied to the points inherit this name attribute.
- The RBD Bullet Solver compares the name attribute of the copied objects to the points of the poly line constraints (each poly line constrain has two points, e.g. piece0_2 for the ground polygon on which the point was scattered and sphere_0 (which is the centroid of the copied object). If the match, they will be constrained.
I have a question: In the Attribute Wrangle, you have this code:
s@constraint_type = "all";
Is the purpose of this to lock the rotation and position of the copied objects to the surfaces so the stay in position and do not wobble? Are the options for @constraint_type either: "all", rotation" or "position"?
- The Attribute Randomize creates unique random values for pscale so this can be used later by the Add node to create the constraints.
- The Attribute Wrangle right under the Attribute Randomize renames the scattered points (so name: piece0_2 becomes name: sphere_0, etc), The piece_* will be associated with the fractured ground and the sphere_* will be associated with the copied objects so they can be constrained together. When these are attributes are fed in to the Merge node, the duplicated points with have the same pscale value.
- The Add node creates a polygon line (constraint) between each set of two points that share the same pscale value, i.e. overlapping duplicates. (Since the duplicate points overlap each other, the created constraint is actually just made of a representative “line”).
- The renamed points (sphere_*) are fed to the Copy to Points node so that the objects that are copied to the points inherit this name attribute.
- The RBD Bullet Solver compares the name attribute of the copied objects to the points of the poly line constraints (each poly line constrain has two points, e.g. piece0_2 for the ground polygon on which the point was scattered and sphere_0 (which is the centroid of the copied object). If the match, they will be constrained.
I have a question: In the Attribute Wrangle, you have this code:
s@constraint_type = "all";
Is the purpose of this to lock the rotation and position of the copied objects to the surfaces so the stay in position and do not wobble? Are the options for @constraint_type either: "all", rotation" or "position"?
Technical Discussion » Constrain objects to fractured RBD pieces?
- litote
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Thanks for the file vicvsh. Unfortunately I get errors using it in v18.5. The RBD Constraint Properties shows an error.
Technical Discussion » Constrain objects to fractured RBD pieces?
- litote
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If I fracture a ground surface to break apart in an RBD simulation, is there a way to constrain objects to each fractured piece (like cactus plants on fractured desert ground) so that when the ground fractures, the plant objects attached to each piece will stick and move along with the broken pieces?
Technical Discussion » Use constraints for both colliding objects?
- litote
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Hello Thomas,
I have some familiarity with the RBD Constraint Properties node but I am not sure how to set up the constraints to feed them in to the Rigid Body Solver. This is my attempt, which doesn't seem to work. I named the Constraint Name differently for each object, assuming this may be necessary? I want to make the two objects collide and fracture and control their constraint strengths separately. Is this even close?:
Click here for image [ibb.co]
I have some familiarity with the RBD Constraint Properties node but I am not sure how to set up the constraints to feed them in to the Rigid Body Solver. This is my attempt, which doesn't seem to work. I named the Constraint Name differently for each object, assuming this may be necessary? I want to make the two objects collide and fracture and control their constraint strengths separately. Is this even close?:
Click here for image [ibb.co]
Edited by litote - Dec. 11, 2023 03:09:24
Technical Discussion » Use constraints for both colliding objects?
- litote
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Is it possible to have two fractured objects collide using the bullet solver and use constraints separately for each so that you can set the constraint strength differently for each one? If so, what would be the set up?
It seems the Rigid Body Solver looks for one constraint input only from one Constraint Network, so I am not sure if this could even be done.
I have tried creating two Constraint Networks -- one for each object -- and then using a Merge node (set to Affector Relationship: Mutual and Relationship: Collide Relationship) to feed them in to the Rigid Body Solver, but the result does not go as expected.
It seems the Rigid Body Solver looks for one constraint input only from one Constraint Network, so I am not sure if this could even be done.
I have tried creating two Constraint Networks -- one for each object -- and then using a Merge node (set to Affector Relationship: Mutual and Relationship: Collide Relationship) to feed them in to the Rigid Body Solver, but the result does not go as expected.
Edited by litote - Dec. 11, 2023 01:31:05
Technical Discussion » Render from ACES color space to srgb directly?
- litote
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Technical Discussion » Recommended workstation for Houdin simulations?
- litote
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What would be a good model of workstation for running and rendering FLIP and RBD sims with Houdini? I am not looking to spend a risdiculous amount, it does not have to be a super computer. I don't want to build it, I just want a model that is from a company that would have after sales servicing should I need repairs, e.g. Dell.
Technical Discussion » Render from ACES color space to srgb directly?
- litote
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jsmacklitote
I am no so familiar with Karma. Do you know if it can be done with Mantra?
If you render to mplay, it now has the option to apply a display-view transform when saving to ldr formats or when exporting to video.
Could you give me more detail on how to actually set this up to render? ACES comes with some LUTs, do you apply one of these to convert from ACES to sgrb? How, exactly?
Technical Discussion » Render from ACES color space to srgb directly?
- litote
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Technical Discussion » Render from ACES color space to srgb directly?
- litote
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Is there a simple way to render an image sequence from an ACES colour space in Houdini directly to an srgb format for posting on Youtube without going through Nuke or another compositor to convert its gamma so it look right?
Technical Discussion » Question on ACES colour space for Houdini/Nuke
- litote
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If I use the ACES (OCIO) colour space in Houdini, when it comes to the final render, say for a Youtube video, do I need to convert the render to a gamma 2.2? If so, how do I do this (using Mantra).
And if I render out the ACES version of the image (linear 1) and bring that in to Nuke for compositing, I know I must set Nuke to the same ACES colour space, but again, in the final output to Youtube or whatever, do I need to Grade it with a gamma of 2.2?
Presumably I must do the same if using After Effects?
And if I render out the ACES version of the image (linear 1) and bring that in to Nuke for compositing, I know I must set Nuke to the same ACES colour space, but again, in the final output to Youtube or whatever, do I need to Grade it with a gamma of 2.2?
Presumably I must do the same if using After Effects?
Technical Discussion » Do studios work with Indie-licenced freelancers?
- litote
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Can someone tell me if an Indie licence (which does not allow you to integrate with commercial licence projects -- i.e. file format can not be opened) is still commonly used by freelancers when working with studios?
That is, do studios generally require you share Houdini project files that are compatible with their commercial licence, or do you just send them a rendered output?
That is, do studios generally require you share Houdini project files that are compatible with their commercial licence, or do you just send them a rendered output?
Technical Discussion » Will Houdini run on Mac Pro 2013 "trash can"?
- litote
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Does anyone know if Houdini will run on the old Mac Pro 2013 "trash can" models? I don't know if they would be compatible, e.g. if the have SSE 4.2, etc.
If so, is it worth considering for running simulations (fluid, etc), given hoe inexpensive they are?
If so, is it worth considering for running simulations (fluid, etc), given hoe inexpensive they are?
Technical Discussion » Anyone use a 2019 Mac Pro (Intel) for Houdini?
- litote
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I am considering getting a 2019 Mac Pro (Intel) to run Houdini on. The graphics card for the model I am looking at is a AMD Radeon Pro 580X, which is not on the supported list. Does this mean Houdini would not run at all, or would it just be subject to more crashes? I am currently using a 2018 MacBook laptop and althiugh the graphics card is also not on the list, it does run, although some of the functions like the advanced viewport lighting don't work.
Can anyone share their experience with using a 2019 Mac Pro (Intel) and share their configuration (especially graphics card)? Do you experience many crashes running sins like FLIP and RBD? If so, how often?
Houdini lists SSE 4.2 as a requirement, but this model has Intel® AVX-512. Would this still work? Can someone confirm?
Can anyone share their experience with using a 2019 Mac Pro (Intel) and share their configuration (especially graphics card)? Do you experience many crashes running sins like FLIP and RBD? If so, how often?
Houdini lists SSE 4.2 as a requirement, but this model has Intel® AVX-512. Would this still work? Can someone confirm?
Technical Discussion » Pyro Solver (Sparse ) node question
- litote
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In the Pyro Solver (Sparse) node in its Flames tab, under Smoke parameters, what does Flame Range do?
I know it affects how smoke is generated from flame, but am unsure of how it functions. Does it only create smoke based on the flame value between the two range values? Is the incoming flame value set between 0 to 1?
I know it affects how smoke is generated from flame, but am unsure of how it functions. Does it only create smoke based on the flame value between the two range values? Is the incoming flame value set between 0 to 1?
Technical Discussion » What is Bindings tab in Pyro Bake Volume?
- litote
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Technical Discussion » What is Bindings tab in Pyro Bake Volume?
- litote
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Can anyone explain what the Bindings tab in the Pyro Bake Volume node is used for, and give an example?
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