Thank you for the information guys, it's much appreciated!

Hi All,

I have searched the forum under a variety of names, but have yet to come accross anything that mentions how to render a Point Pass (world space) out of Houdini. It's quite possible that I'm just not searching for the correct term.

I found the following information for Maya (from the Sphere vfx website)

http://www.spherevfx.com/html/trainingArticles01.html#10 [spherevfx.com]

The image attached shows the pass I'm after (right image).

I would like to find a way to render the same pass out of Houdini if possible.

Any suggestions, directions, etc. would be much appreciated.

Thank you for your time.

Hi All,

I have no experience with creating 3D LUTs in Houdini, but am interested to learn how this can be done. Does anyone have a quick and simple example that I could use to learn from?

Any help is much appreciated.

Thank you

Hi ladies and gents,

Does anyone know a way in which I can put an animated cameras T,R,S matrix information into an exr's Metadata? Any nifty Python scripts that can possibly be placed into the Output.. Comment field to extract this information?

Thanks for your time

Cheers,

Sean

Ok, so there are a few things that I didn't know about the Sequence Blend SOP.. firstly, if you string together a set of ‘affector’ nodes (i.e. my soft-transform nodes) and then wire each of those individually into the sequence blend, the transformations happen one after the other, providing you with a delayed affect of sorts. At the same time you can have ‘affectors’ included in the node string for the overall ‘affector’ input of the sequence blend that don't have to be wired into the sequence blend individually.. which means that they will take place at the same time. With a little bit of elbow grease you can put together some pretty non-uniform-timing for a group of transformations. I have used wave data (a sine wave) in CHOPs to drie the blend channel.. and by multiplying the waveform with a math CHOP I can equal the number of operator inputs ('affector' inputs) for the sequence blend, and gain some pretty great control over the timing of the seperate transformations. Still going to look into the lookup CHOP though.. appears to be a very very powerful tool to have in ones arsenal.

Thanks for all the input everyone .

Cheers,

srgb

(I'll post a video after the project hand-in)

Thank you both very much. The help is much appreciated.

Hi SYmek,

I had a look at the Lookup CHOP tutorial stuff and its flying right over my head.. (might be that its late and I'm a little wired on coffee ..but its making me feel a little stupid right now.. I think I need much more time to examine it). I have decided to go back to your earlier suggestion.. but yet again, I feel foolish in having to ask where abouts I would enter the expression? (I'm a real newbie at all this unfortunately). Would I be looking to implement it at CHOP or SOP level? I do apologise for such lame questions, I truly wish I had more time to get to grips with this stuff.

Thanks for all your help,

srgb

Thanks for the suggestion SYmek!

I have no clue about the Lookup CHOP in terms of its use or capabilities, but I've stumbled across Jeff Wagner's blog tutorials that look into using it. I'll get stuck into those, and hopefully soon be able to put what you have suggested into practise.

Cheers,

srgb

Wow! Thanks for the fast and detailed reply SYmek! I'll take a little time to unwrap what you have posted, but it looks great .

Thanks again.

Cheers,

srgb

Hi all,

I've come into a bit of a problem with the beating mechanism for my heart model. I am using a heartbeat soundwave through CHOPs to drive the blend channel in a sequence blend SOP, essentially deforming the geometry between two states (attached image: file 3 is the bgeo of the heart). I started off using the magnet SOP with metaballs to do the deformation, but changed to the soft-transform SOP as it gave me better control for shaping the geometry. Everything works with the deformations.. my problem lies in the fact I want the soft-transformations to happen at different times (slightly after one another as the different areas of the heart expand/contract at different times).. at the moment they all happen at the same time. I have very little knowledge of expressions in general.. especially with regard to how I might delay the channel data feeding into the separate deformations (or its reaction to receiving that data) .

Anyone have any ideas? I wish I had more time to learn about expressions with regards to time, but my project due date is looming and I just don't have time to explore it. If anyone can set me off in the right direction I would be ever so grateful.

Thanks for your time ladies and gents.

Cheers,

srgb

Thanks Arctor, I'll give it a bash when our network comes online again.

Hi ladies and gents ,

I have a polygonal heart that is suspended in mid-air by three of its tubes which are attached to three perspex ‘paddles’ (image attached). I am looking to make the tubes dynamic in a way that they are elastic enough to allow for some stretch (but not too far so that the heart hits the base of the perspex stand), and keep the heart suspended in its mid-air position. My intention is to have the beating of the heart cause it to wobble around a bit in the air whilst suspeded by its tubes. I have no experience in DOPs, and am a bit uncertain of what to be searching for in terms of methods to use to achieve this. If anyone has any ideas or can point me towards relevant posts you have come upon which might set me off in the right direction, I would be very grateful for the help.

PS. (The heart textures and passes are far from being completed, this is just a rough comp to give you an idea of what the situation is )

Thanks for your time everyone.

Cheers,

srgb

Thanks Arctor, I'll take a look at those two methods as soon as I can.

I'm trying to leave the pericardium out of the model if possible.. but its a neat idea, so if push comes to shove I'll be looking in that direction for sure.

Thanks Arctor.

srgb

Hi Ladies and Gents,

So, I've managed to reach a semi-completed status for my polygonal heart model (the tubes need to be extended later to suit my needs, but the main body is done). What you can see in the diagram is a replica of a human heart minus all the fatty tissue that makes up the gaps between the shown chambers. (I have not textured it yet.. thats for a later date).

I am now looking towards filling the gaps with something resembling a fatty-tissue substance (like the yellow stuff seen in the real-life picture). I had thought about using the rather indirect modelling method of cookie'ing the heart with another geometry object so that I am left with triangulated geometry ‘flowing’ between the gaps. I could then chop that up into a shape that fits with the contours of the heart chambers, and subsequently recreate a (quadrilateral) polygonal version of this triangulated geometry using the ray SOP and some other methods I used for the heart. Phew! :? As you can see this seems to be a really indirect and drawn out way to do it…

Does anyone have any alternate modelling methods that I might be able to use to fill in the gaps (the very obvious area on the left side, and all the areas in-between the tubes)?

Any suggestions would be greatly appreciated .

Thanks all,

srgb

Hi ladies and gents,

I have a very complex (triangulated) organic reference model that I am trying to replicate using polygons. The model is hollow (one continuous surface after cookie'ing everything together), but it contains multiple chambers, and tubes going out from the chambers which connect with one another in certain areas. I have attempted to use a subdivided cube with the RAY SOP to form the shape of the geometry, but unfortunately the primitive faces that go out towards the surface of the reference model are intersecting in parts due to the directions of the cubes primitive faces (leaving me with a mess of geometry). I was trying to create a multi-directional vein of sorts (by polyextruding a cube) so that I could put it through the ray SOP in order to achieve a continuous polygonal surface, but its giving me a hard time .

If anyone has any suggestions for me of ways in which I could manipulate the RAY SOP to achieve my polygonal replica, or any alternate method, I would very much appreciate the advice and direction.

Thanks for your time.

Kind regards,

srgb

Thanks for the example Andrew , I'll give that a try as soon as I can.

Thanks everyone .

Great example cpb, looks very much like what I am intending to achieve. I don't understand everything that you have done, but I'll spend some time dissecting your network to see how it all works.

I'm going to give andrew's idea a try as well to see what I can achieve. (another thing I don't quite understand yet.. but I'm always willing to learn)

Good weekend to all,

srgb

Hi,

I am trying to animate a single wire-like object to look as though it has a wave travelling down it (i.e. when you take a length of rope or string and shake it from one end.. the ‘wave’ moves down its length). I've done some tests in CHOPs and come up with the attached hip file.

Now my challenge is that I want to have each end of the rope constrained to a static point, with the wave still happening along the rest of the rope. I thought that I might have to somehow transfer the CHOP wave data into a DOP network that contains a wire.. but I have no idea how to do this at this present time. Or, if there is some way to constrain the end points using a points SOP possibly?.. this too, I have no idea how to do yet. Any ideas would be much appreciated.

Thanks for your time .

cheers,

srgb

Hey tankboy, here's just a little test on your file to get a more random look about it. Not sure what you were using it for, but this sort of resembles the animated sequence example you posted.

hip file is attached .

cheers,

srgb