sorry for disagreament, but the DVD which was mentioned is NOT worth its price since it explains absolutely basics, which are covered in free tutorials from SESI and 3dBuzz. In all 5.5 hours there are maybe three interesting tricks. I am sure, that Mr Garman Herigstad is high qualified specialist but this DVD is not well considered. I don't want to be rude, since its clearly written on the DVD cover that it explains fundamentals of Houdini workflow, but in this case “fundamentals” means “show me differences between common software and ”procedural approach" application - which is not what I was expected.

Its much better to download free vtms from 3dbuzz.com or SESI video (they explain the basics of Houdini much more consistently and deeper) and wait for more advanced DVDs from Gnomon. I would love to see 5 hours of expressions lessons… or VOPs… or POPs… or DOPs…. or…

well… ipr lets you use accelerated rendering by caching part of render data, which won't change during some tweakings of your scene. For expamle playing with colour of light, dimmer or its position does not change displacement of your geometry, so there is no sense to recompute it after such change. Insteed of that, ipr uses a cached data and render only colour component of the surface, which is of course much faster.

Go to your ROP driver parameters tab and turn on ipr rendering at the very top of this tab.

As I understand (not sure of that) you can work with ipr both in standard viewer or its ipr version. Only difference is a workflow. In ipr viewer you see your changes immediately. In standard viewer you have to push render buttom.

Make tests! Render your frame few times changing some parameters with and without ipr. Turn on Verbose in Mantra (mantra -V 1) and you will see advantages of IPR. (which is quite common out there…)

thanks for replay.
Maybe I will join You next year on Siggraph. I got only 15000km to LA, one year of riding on my bicycle should be enough. I'm only concernd about the Ocean…

There are any chances for extensive news, materials, from SESI presentation on Siggraph - something like a PRMan Sigg. courses? Does anybody care about publishing such stuff or due to some issues I don't realize it's imposible?

thanks for replays.
I use ConvertMetaball but still during the time there is a change in a point number of my fluid object so it looks like a flock of jumping rats under a carpet… I convert metaballs to palygons for subdividing them in order to give it some more details… maybe it's not a good idea.

As to Realflow… it is a great software but I don't like it since…. it simulates fluids phisicly! which means that you hardly can control your scene. If I want, for example, my milk jumping out from a glass after it has flown in to it - well it's really tricky. That is why I try to do it entarily in H.

thanks again.
symek.

Hi!
Does anybody could explain me basic workflow of particles/metaballs effect. Maybe some tips can help. However I try to change a parameters of particles amount and metaballs size and weight, the final mesh behaves strange. I need a sumulation of fluid on some basic level and as to particles everything satisfy me. But when I copy metaballs on them and convert them to polygons, mesh starts to jump from frame to frame, so geometry looks like it changes its topology (since particles move, die, collide etc. it's quite obvious but ruins my scene). I though that this is a general way to generate such an effect. Am I wrong?

Scene is a milk flowing from a bottle to class and it does not have to be very realistic, let it be a mud flowing to class…

thanks,
SYmek.

well, that what I am doing, I got two ver. of tex, for OpenGL and for txmake. I've just was wonderd if this is common issue or it's just my ignorance. I even don't comply…, after hard work in shake I understand that for some apps. tile ordering is a matter of life or dead . Thanks.

edward: I use sixth and convert textures from large jepegs to tiffs and… rats Maybe there is some global variable or switch to change tile ordering in H…


thanks for reply,
Symek.

ye! you see, I'm telling him that for a whole last week, but I'm afraid (maybe because of my english ) he still stands on this that he must do it in render… I don't know, I don't know….

I've never in my life done glow in 3d render… is it mean that i'm not a child?

cheers,
symek.

do you really have to use zdeph map? maybe you can rander that one object a composit it without zdeph…. I can not imagine situation in which zdeph is absolutely nessesery… it can helps form time to time, speeds up some comps, but generally you always can do your comp without zdeph.

another thing is that I cannot understand to what porpuse you use zdeph in that context. Glow is filter which influances pixels colour aroud your object. IT does not touch your zdeph…. Object can be composited, just mask it to apply glow on it only rather than on whole plate.

ok, I think I understand now, you know, you always can add your glow after you composit your object. DO you know how glow works or you just use some ready-to-use filter? Make a copy of your object before composition (without background), make it B&W, up contrast, up brightness, blur it, now add this on already composited picture with SCREEN, or ADD mode. Oh! Of course you must change colour of glow multipling it by colour of your obcejct.

If you want you can send me one frame for every layer of comp., I will try to solve it and will send you results with some remarks .


cheers,
symek.

Why RMan rendering texture Y-direction is oposite to viewport? When texture in viewport displays correctly, in rendering is upside down…

is it something with a tiling/pixel order within tiffs? How to change it? Maybe there is some switch in txmake? Now I must make two versions of one texture: for OGL and for RMan.


thanks.
Symek.

yes, it is a misuderstanding:
rla is a kind of image format which does not specify a number of channels/plates: Discreet uses this ability to pipe into rla files shade pasess and some (maybe useful ? ) data like surfaceID. Deepraster is a internal data of renderer which can be exported to any image format (which support correct type of data - integer, float etc…).

Deepraster in Houdini can export data also to rla. Rla can store deepraster data in the same way as colour, alfa etc, etc.

ok?
cheers,
symek.

I don't think so, but it does not mean, that you can't output from Rman such data as you want. Look in Rman doc for details.

of course, since RLA is open format and supported by Houdini you can use it inside Houdini. But just from definition of RLA does not follow that it have to be used to bring you info about surfaceID or any other. What is specific about RLA id that it does not have defined number of channels - which means that you can pipe-in it any number and any information you want… or your renderer/shader can.
Mantra can bring you in rla (or few others formats) some variabels, try deep-raster tab in Mantra ROP. If you need some others data you will have to write shader which will define it and write down in variable.

hope this will help,
symek

to be honest… I don't see your scene and it's hard to me to imagine where is your problem, but one general remark is that glow is a last thing you want to render in 3d! Maybe there are some circumstances in which it is necesery, but in general this is a last choice! Try render your lamp separetly and add glow in post. You will have better control over hole scene and glow will look much better. You propably want to add it on your lamp in screen or Add mode, which means that you won't have a problem with alfa.

best,
symek.

o my God!
that was so easy! Funny thing is that I often use this buttom because my vga is very slow…

I dived inside every corner of H. setup… and the answer was right at the front of me and well known.

thanks,
symek.

… and to be more specific? where do you have a problem.

hello.
I think that I had changed accidently some feature in interface setup and now I can not find where i can repair it. Any changes made by handles or paramiters tabs (scaling, rotat. trans… anything) display after all… when I drag off handle or leave parameter alone. Quite confusing when you want to play around with your parameter and find good value.

Any solution?

thanks!
symek

well… i'm not a very specialist of Houdini but as I know from other software it is enough to use glass shader and change index of refraction to some higher value. Double sided surface is also good idea. (of course lenses should be sphered to give rays chance to brake on it diffrently…)


Another idea (depending on type of shot) is to make this effect in compositing. As you expect it is much faster. Just render your object (lens) as a matte, track it in compositon, add a gradient color from a center to edges and use it as a mask for distortion of original render object.

hope this will help not confuse…

symek

yes… I'm so stupid that I didn't look first inside wiki… It should be common behavor. First look then ask.

thnx.
symek

thank you, that is what I was looking for

symek.