Revision as of 14:12, 3 August 2017 by Mariomeissner (talk | contribs)

Mario Meissner SOCIS 2017 Logs


Build successfull on Arch Linux (Antergos) x64 Working my way through the Introduction_to_MGED.pdf


Successfully calculated mass of a copper sphere using rtweight.


Diving into the source code of rtweight. I will need some help understanding the overall structure of the repository and some details about rtweight.


Proposed an initial model of representation. I would use a three-variable function that returns the density of the material at a certain point in space. Integrating this function over the boundaries of the object yields it's mass. Example can be found here:


Started working on the example raytrace application. I am setting highest priority to understanding the basic behaviour of this little program, as I know it is the foundation I will need in order to continue with the project.

I will try to modify it in some ways and see if I break it.

From today onwards, I will be working from 15:00 to 22:00 most days, and from 10:00 to 13:00 as well a few days a week. After evaluating how much can be done with this schedule, adjustments will be made accodingly.


Drafted an example of how to obtain a function that returns the density a ray sees at it crosses the object.


Reading through, understanding and compiling the example applications.


Modeling the sword and continuing yesterdays work.

Starting with the candle example to get practice.


Making new, blade that actually fits the specifications; remaining time digging through the viewweight.c code.


Designing proper density model that allows for good implementation.


Studying source code.


Setting up eclipse development build and studying source code.

Facing problem where Eclipse does not properly recognize tons of symbols in the code, including basic types like "FILE". One candidate solution is to browse to the C/C++ pre-processor settings and adding and configuring the CDT GCC built-in compiler. Details here:

However performing the steps on there crashes the indexer while it's updating.

I'm using Arch, Eclipse Oxygen and the latest available GNU compiler suite. I built the project for eclipse using CMake following the guide over at wiki/compiling.

Thinking about how the user should input the density data and how we should handle it inside, I found this to be relevant:

We could let the user set any number of points throughout the material with specific densities, and then we can apply a simple curve fitting algorithm to create a continuous density function. This function could be stored in some struct or array and then be used to return the density value at any given point with precision. These requested points could be used for interpolation by the calling code.


New goal: modify the example application to shoot a ray to the object and calculate it's density assuming it's a 0 to 1 change.

Working on goal.

Results: screenshot


New goal: snippet code to read density points from command line into data structure.


Debugging yesterdays work.

Managed to make it work to a point where I think the goal has been reached. Further expansions of this goal may be made once more is known about the density specification.


New goal: write simple function that returns the density value for a material at any point in space, for simple specifications (a few density_points at max).

Working on goal.

Todays work: [1]


Continuing with yesterdays work. Decided to make a new structure to store vectors and their factors. We can go through the list of provided points for a material specification and compute the vectors we care about, push them to a list.


Received feedback on yesterdays work. Apparently I tried to do breadth first, which resulted in too ambiguous code that obviously wasnt working yet either. Today I tried to revert that and made a simpler situation work. Figuring out how to properly use vmath macros and bu_lists, as well as debugging my mistakes, took away most of my time today but I feel it was an enlightening process. Emailed results.


Day off


Partial day off. Woring on blade.


Finished blade curve.

Working on density(), will try to make the vector list work.

Facing a little design problem. If we have a vector_list, we need to be able to keep track of who's vector each projection is. We cannot store it inside the vector bc we will want to reuse them. One solution could be creating struct contribution and store a pointer to the vector it came from. After all we only need the factor. Another solution would be to calculate everything necessary (projection and contribution) within the loop and then throw away the information.

Mario Meisner.