Krakatoa

#941

few hours back i was trying enviroment reflection property of krakatoa and for refrencing i used krakatoa documentation given on prime focus website.

i had followed all the steps given there but i was not able to get reflection as shown in docmentation,here i am telling what i had done…

firslty i took sphere after that simple pflow node to generate particles from sphere then loaded a hdri image(max’s default hdri),then i turned on use enviroment reflection option in krakatoa but instead of reflection i am getting some part of color of hdri which i loaded so please tell me what i am missing in whole process

#942

Is it possible to render FumeFX emitter’s particles in Krakatoa?
I tried a few scenes but I can only get to render a few hundreds… there’s no such a thing as the particle amount in the FumeFX emitters… (I think).

Thanks.

#943

yes its possible but please elaborate more what you want to do

#944

the amount of particles derives from the grid size in fumefx. it will display every voxel as a particle. If you want to achieve a higher density you need a smaller fume grid(higher density) there for or use tricks like offestting 2 prts maybe amoung others.

definitely check this link:
http://software.primefocusworld.com/software/support/krakatoa/fumefx_direct_rendering.php

#945 
 Reflections require correct Normals.

From the documentation:

Environment Reflection Maps

Available in Krakatoa v1.5.0 and higher

Introduction

[ul]
[li]Krakatoa can use the Environment Map found in the 3ds Max Environment Dialog as an additional light pass by looking up texels of the map along the particle Normals (if a valid Normals channel is provided).[/li]> [/ul]

The Normal in Krakatoa is taken from the X axis of the particle’s Transformation Matrix. By default, all particles are oriented uniformly with object space matching world space, so the X axis is along the world X and would give you some color along that vector.

 So you will have to make sure your particles are aligned to the surface correctly - we even provide a [Krakatoa Geometry Lookup operator](http://software.primefocusworld.com/software/support/krakatoa/krakatoa_geometry_lookup.php) that does this in almost no time. Alternatively, you can [use the Speed By Surface / Speed Follow trick known since Max 6](http://www.scriptspot.com/bobo/mxs5/pflow/pflow__Hairy_Teapot.htm) or Orbaz PFlow Toolbox Box #3 operators, but with the operator we have provided, it should not be necessary.
 
 Once you have correct normals, the color of the environment along the normal vector will be shown on the particle as a form of "additional lighting".
#946

Well… how do I tune the amount of particles being rendered via Krakatoa if the particle emitter is a FumeFX emitter? I wouldnt want to change the smoke density parameters for example as that would influence the physics of the simulation.

Thanks

#947

As Ansi explained, we currently create only one particle per voxel.
When we wrote this code, we had to solve a practical production problem on G.I.Joe - the FumFX sim we had to render required around 64 GB of RAM. So we decided to make Krakatoa render the FumeFX in voxel mode and needed one particle to transfer the data to our voxels.
When we added this as official feature in v1.5.0, our other tool, the PRT Volume, was also only able to create one particle per voxel.

Then in v1.5.1, we added the ability to create multiple particles per voxel in the PRT Volume, but did not do the same for the FumeFX rendering. It is currently on our Wishlist to provide the same multi-particle functionality to FumeFX rendering in the future, but I cannot tell you when exactly. Also, in the case of PRT Volume we have the mesh surface to check against to ensure correct curvature, while in the case of FumeFX we have no such guiding surface and producing multiple (grid or random) particles per voxel would not necessarily smooth out low resolution voxel grids, so it might require some more advanced techniques to produce good looking results.

The alternatives would be to create particles in PFlow and drive them with the FumeFX sim as we did in the early days before direct rendering was supported in Krakatoa, or save the FumeFX to PRT, load in a PRT Loader and partition it using the High Frequency Noise Modifier method described in our tutorials. This would give you a random number of particles per voxel with the current tools…

#948

thanks for such a great help @bobo

but here is another problem which i am getting during rendering test file given here

http://software.primefocusworld.com/software/support/krakatoa/shadows_on_geometry_tutorial.php

i didnt got any problem while saving particles and loading them but when i try to render particles Max crashes immediately everytime.

i tried rendering other file using process given for generating particle shadows but same thing happens again and again.

after working some more time on krakatoa i come to know that max crashes only when turned on “save attenuation” option in krakatoa.

#949

Sorry, this is an actual bug that slipped into the Max 9/2008 and 2009 builds (it isn’t really a bug as such but was caused by some compiler settings that were changed back and forth lately). It should not crash in Max 2010. If you are using 2010 and it is crashing when saving Attenuation Maps, please let me know.

The problem has been fixed in the Beta of 1.5.2 which customers with a valid support contract have already access to via our Beta forums. Once finished, v1.5.2 will be released for everyone to enjoy.
I am not sure whether v1.5.0 had the same issue, but since I wrote that tutorial with it, I assume it was ok. You might want to try installing 1.5.0 and doing the tutorial in it until we release the official fix.

#950

today i tried to get enviroment reflections again on object (Teapot) using “krakatoa geometry lookup operator” but i didnt got any reflections on particle surface…

here i am telling what i had done

Simply taken a teapot used basic operators to get particles emitted from teapot surface and for enviroment reflections choosed default max hdri after that taken a “krakatoa geometry lookup operator” and placed it in pflow event then choosed teapot in “krakatoa geometry lookup operator” and after that when i am rendering particles i am only getting a “grey color teapot” i think i am doing something with normals but i dont know how to correct it.

Someone please expand it step by step so that i can get basic reflections in just one go after that i will play with settings to get desired output.

#951

Here are the steps for Environment Mapping:

*Created a Teapot
*Created a Standard PFlow
*Generated 200K particles on frame 0
*Replaced Position with Position Object, picked Teapot
*Replaced Speed with Krakatoa Geometry Lookup.
*Picked the Teapot in the KGL, unchecked Use for Position and Barycentric Coords AND CHECKED NORMALS, Put Into > TM.
*Deleted the Rotation and Shape operators
*Opened the Environment Dialog, added a Bitmap texture with some image file
*Dragged the Bitmap into Material Editor, switched from Screen to Spherical Environment
*Opened Krakatoa GUI, turned on >Use Environment Reflections

RESULT: Got reflections color on my particles.

#952

wooohoooooooooooo i got reflections

thanks bobo

#953

hi there. could you suggest any setting to achieve a more “ink in the fluid” result like in the cctv animation (http://www.vimeo.com/6794856) because I could only get a more “sand particles” effect in my tryings… :frowning:
thx !!

#954

I would suggest reading this topic:
http://software.primefocusworld.com/software/support/krakatoa/fighting_the_grainy_look.php

It tries to demonstrate how lower densities with higher particle counts change the look from “sandy” to “wispy”.

Hope it will help…

#955

thx a lot for this…really useful post!! and compliments to your great job on GIJoe !!!

#956

Dear Bobo,

I notice particle flow will just emit part of particles when I set it connect with fumefx.

Fumefx and pflow are run normally, but krakatoa just render a volume of it.

I set the creation of emit 0-100. (As my attachment.) But seens doesnt work.

here is a example:
http://vimeo.com/8837536

Thank you!

#957

I fail to see the connection to Krakatoa. You are connecting PFlow to FumeFX. If there is a problem, it is in one of them, or in your setup. I cannot tell where, but if you can explain what it has to do with Krakatoa, then I can take a look…

#958

Hey dim1984kimo

can you show us the fumebirth settings if you use one or maybe the whole PFlow tree with settings.
nobody can tell anything if we do not know what exactly you are doing, what settings you use.
I think your particles emit problem comes from the settings you use as in your video it does work, just not good enough :slight_smile:

cheers,
Bandu

#959

Sorry, I set the upper particle number to limit the particles…

My mistake.:sad:

#960

I am NOT suggesting you should see this movie (I haven’t), but if you happen to see The Rock in “The Tooth Fairy”, all the fairy (amnesia) dust was done in Krakatoa.
(the CG wings were rendered in VRay, but some were practical).

http://www.primefocusworld.com/work/portfolio/tooth-fairy-twentieth-century-fox