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Alice1

Render a simulation

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HI All,

Sorry for my question as It can be very easy for someone that knows how to use Houdini but I am a beginner and I cannot find a solution..
I am just trying to render a flow simulation but instead to render the flow simulation It renders a grey object , I suppose It s the initial geometry... How to hide It in the render ?

I have attached here 2 screenshots to show you better what I mean annd hope you can help,

Thanks a lot !

 

 

6.PNG

7.PNG

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If I undertand it correctly you want to render the velocity visualisation in the lower image, not the volume is that correct?

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Hi Haggi , 

Yes correct , I want to render the lower image but when I render I have the first image .. 

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What you see in the lower image is only a visualisation of the velocity field, not the final geometry. A fluidsource node is usually used to create volumes for fluid sims. If you want to render the trails, you can scatter points in the volume and use a volumetrail sop to create trails which can be rendered.

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3 minutes ago, haggi said:

What you see in the lower image is only a visualisation of the velocity field, not the final geometry. A fluidsource node is usually used to create volumes for fluid sims. If you want to render the trails, you can scatter points in the volume and use a volumetrail sop to create trails which can be rendered.

Thank you !  I’m trying to find a tutorial that can help to show step by step , please if you know a good tutorial for this let me know as even if you explained I understand what you mean but I want to see once how to do it in Houdini ,

 

thanks a lot ! 

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On 19/01/2021 at 4:08 PM, haggi said:

Very first result if I search for "render velocity trail houdini" on google: https://entagma.com/colored-trails-point-advection-rendering/

:)

HI Haggi, 

I tried to follow the tutorials and work ok but the problem is that I won t have the same geometry =( , So I have a new trails but not the actual simulation, I attached here 2 screeshhots to show you better what I mean, I really tried everything, 

 

10.PNG

11.PNG

fluid_.hipnc

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I think in this case the easiest way is to click on the fluidsource sop with the right mouse button and select "Allow editing of contents". Then dive into the network and set the display/render flag to the "GUIDE" null sop.

fluid_.hipnc

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1 hour ago, haggi said:

I think in this case the easiest way is to click on the fluidsource sop with the right mouse button and select "Allow editing of contents". Then dive into the network and set the display/render flag to the "GUIDE" null sop.

fluid_.hipnc

HI Haggi, thanks a lot but I cannot see "Allow editing of contents" and when I dive into the network I m confused , I have no hope,  sorry for taking so long time  =( 

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Click on the fluidsource node with the right mousebutton and then a popupmenu should appear which looks like the one in the image. There is a menupoint "Allow editing of Contents" at least in my Houdini. BTW. did you have a look at the attached hipfile?

allow.jpg

Edited by haggi

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37 minutes ago, haggi said:

Click on the fluidsource node with the right mousebutton and then a popupmenu should appear which looks like the one in the image. There is a menupoint "Allow editing of Contents" at least in my Houdini. BTW. did you have a look at the attached hipfile?

allow.jpg

HI Haggi ! 

Sure ! It s because I downloaded your file and you already clicked on Allow Editing of contents but If I go to my previous file I can definitely see it !

I am trying to understand this now : Then dive into the network and set the display/render flag to the "GUIDE" null sop, so basically I am using the file you attached and I am inside the fluidsource and I can see the DISPLAY  but now don t know how to run the render , 

However you should have a prize for the patience , thanks a lot again for your time

 

 

 

12.PNG

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In my file everything is already setup for rendering. Sorry if I did not make it clear. In your scene you can set the display flag to the GUIDE null. And then you can render the geometry, or you simply open my file and render it.

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18 minutes ago, haggi said:

In my file everything is already setup for rendering. Sorry if I did not make it clear. In your scene you can set the display flag to the GUIDE null. And then you can render the geometry, or you simply open my file and render it.

HI Haggi , 

Thanks ! 

That works, If I click in render I have the render now and I guess for changing color of the simulation and for a better resolution I should play in Mantra, isn t It ?

 

Thanks a llot ! 

 

13.PNG

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To change the resolution go to the camera and set the resolution there, or you override it in the mantra render node. And the colors are defined in an attribute on the geometry. To change the colors you try to find the node where it is done in the fluid source sop or do it in Houdin after rendering.

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54 minutes ago, haggi said:

To change the resolution go to the camera and set the resolution there, or you override it in the mantra render node. And the colors are defined in an attribute on the geometry. To change the colors you try to find the node where it is done in the fluid source sop or do it in Houdin after rendering.

Thank you ! :D

 

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