Problems with fluid animation in fountain experiment !!!

After 6-7 hours of agony we have come to the conlusion that , we are dealing with an area of blender which has little documentation , loads of bugs , slow development cycle and very useful to our experiment.

Fluid simulation seems to be working differently on different machines , differently in different versions and also there are some settings which we still have to understand.
For example each time the ratio of the total volume of the fluid in the simulation to the total volume of the cuboid (domain) goes below a certain threshhold , the baking doesnt happen. Now this is a major bottleneck to our project. Either we bake it in a different scene and use it in the complicated scene or we learn how to break down the animation into multiple domains to simplify.
the following are the bugs we have come across while playing around with fluid simulations :

a) viewport doesnt show properly the mesh data.
b) obstacles when intersecting or too close to one an another , baking doesnt work.
c) init shell doesnt work when objects are too complicated.
d) sometimes obstacles dun behave as proper obstackles.

the following images shows the bugs we discovered :







So now our model with the flask and jet through cork wasnt working with fluids , no matter what we did. So we tried to animate the fluid without the model , just using a dummy model in a different blender scene. we could manage to bake it after a lot of trial and error and we hope to get the fluid animation from this scene to work in our original scene. the following are the screenshots of the new dummy scene we made to make the fluid work.




hope somebody can shed light on why blender doesnt bake fluids in our original scene. Also if some one can find any link or ebook which has documentation on blender fluid simulations. any help would be great.

regards
gokul menon

Modelling Progress

Progress in Modelling and Texturing :

Progress has been made in modelling..finally, and the materialisation of the game seems a lot more feasible. the models have been found on various noline repositories and have been suitably modified. nitin's first contraption has been made, and the few glitches have been solved to an extent. The 'Anisotropic' button is used to reduce friction in specific directions. Reducing friction friction in the z direction thus makes the bowling pins behave more realistically. Further progress will be posted subsequently.

Chirag Nitin and Kaeyur

Ammonia Experiment Storyboard

We prepared the story board for the experiment as sir had told us to do.
made it into a ppt , have embedded it here as follows.

Ammonia Fountain EXP Modelling

Gokul & I, alongwith learning the python tutorials decided to start the modelling of the selected experiment. We decided to model the glass flask, the glass jet and the rubber cork without the appropriate textures for the day. We finished the modelling and thought we should try baking a scene where the water goes through the glass jet and comes out into the glass flask. After several hours of trying the same, we did not manage to do so. We are experiencing the same problem we faced last sem. The problem is the water does not pass through the small glass jet. It either does not bake or does not obey laws of physics. If anyone has a solution please PLEASE let us know as we intend on finishing the modelling soon and wish to start the animation.

The following are the pictures of our work today.

Water falling in a glass bowl (revisited)

I remember doing my 1st blender fluid simulation of a water sphere falling inside a water mug. its been a long time since then and i have decided to go back to basics for the ammonia experiment. I just realised that i can use single walled meshes for my flasks and trough instead of the agonizingly complex double walled mesh we are used to creating as blender isnt able to calculate the necessary fluid simulation co-ordinates when fluid is to flow inside or outside the object. But if the init shell option is turned on for an object acting as an obstacle then this difficulty can be overcome. That is what i have done in the following simulation. i made a simple uv sphere , cut it open in half and let it remain a single walled semi circular shapped flask. then i poured fluid into it. the uv sphere acts as obstacle with init shell option turned on. the domain is as usual a big cube. the following picture shows the mesh :
the result is as shown in the video :

this is an interesting development i believe , because if we manage to work with single walled meshes , then our work is reduced to half. its like suppose the project was to one has to count all the leaves in a given tree , then i guess this discovery is analogous to that of finding out that the tree is perfectly symmetrical along one of the axis which efectively reduces the work by half.

regards gokul

Fountain Experiment Script

SCENE 1: APPARATUS INTRODUCTION
Step 1: Introduce Flask, 500 cm3 or 1 dm3 which is completely dry and filled with ammonia
Step 2: Introduce Two-holed rubber stopper to fit the flask fitted with a glass jet
Step 3: Introduce Plastic syringe (10 cm3) half filled with water.
Step 4: Introduce Trough or large beaker which can hold more water than the flask and filled with a mixture of water and an acid-alkali indicator (e.g. Universal indicator)
Step 5: White board or sheet of card to act as a background to improve visibility

SCENE 2: APPARATUS SETTING
Step 1: show inverted flask on who’s entrance the two way rubber stopper has been placed and the syringe has been placed inside the 2nd hole of the rubber stopper. The end of the glass jet with the smaller bore is show inside the flask and the one with the bigger bore is kept free for the moment.
Step 2: The end of the jet with the bigger bore is placed dipped inside the liquid in the trough as shown in the diagram and the white background is placed behind this whole arrangement.




SCENE 3: THE DEMONSTRATION
Step 1: Use the syringe to squirt a few cm3 of water into the flask and gently swirl to dissolve some of the ammonia gas.
Step 2: As the gas dissolves, a partial vacuum forms inside the flask and the external air pressure will force water up the tube and through the jet - forming a fountain (see first diagram). The ammonia gas dissolves in the water emerging from the jet and the indicator changes colour.
Step 3: The fountain continues for some minutes, depending on the size of the flask and the width of the jet. When the fountain finishes, a bubble of gas remains. This is air and its volume gives an indication of how well the flask was originally filled.

Fountain Experiment Schedule

Tentative schedule for the fountain experiment (class 10) is as follows :

28th January - Script of the Experiment
7th February – Python Study
14th February - Modeling of Objects
21st February – Fluid Engine .
28th February – Game Engine and scripting.
7th March – Texturing of Objects.
28th March - Lighting and Camera.
5th April - Rendering & Testing of Experiment.
15th April - Final Product.