So I think now that n-points are working for convex regions, I think the
next steps would be:
- Integrate vectors into existing point system.
- Let the user input vectors through the existing input interface.
- Consider one of the vectors and make it work.
- Consider all vectors. N-point and N-vectors working.
- Check that all edge cases work correctly (no points, no vectors,
many of everything, etc.) and clean up code.
- Modify implementation so that it properly works in all situations
(i.e. concave shapes).
I'm also noticing that the current code is getting quite messy so I think
its time to make a cleanup before continuing. A few aspects I want to work
on:
- What data should the projection structure contain?
- Do we need the absolute position (point) of the projection? I think
no, because in my code I am assuming everything is relative to inhit, so
currently the point and its computation are commented out.
- Is it a good idea to compute the distance to the previous point and
store it into the structure in a loop before starting with density
evaluation? I think it would clean up the last part of the code
considerably, but also uses more memory. I like the idea so I
probably will
do so.
- Are we really good to go using an array? I decided to do so because I
needed the sort function, but there might be alternatives I'm not aware of.
- As mentioned, everything in my code is relative to the inhit point. Is
this a good approach? For example, projection struct has a vector that goes
from inhit to the projection point, but I don't store the origin of the
vector anywhere, so someone using the vector that does not know this fact
may not know what it's origin is. My thought is that these variables will
not leave my environment so a simple comment explaining that everything is
relative should be enough.
I will assume that what I propose doing is good unless I hear feedback
telling me otherwise.
Today I will work on a bit of cleanup and then the first point of my
proposed steps.
Attached goes code with minor cleanup changes over yesterday. If possible,
use this for review.
Happy coding!
Mario.
2017-08-15 22:28 GMT+02:00 Mario Meissner <mr.rash....@gmail.com>:
> Sean!
> Implemented the math and did some bug hunting. I successfully ran an
> N-Point Voronoi example (without vectors for now).
> I shoot a ray from above at my 1000mm box. I set density points at heights
> 600, 400 and 200 with density values of 20, 10 and 5 respectively. Expected
> result is 13.5 average density throughout the segment from height 1000 to
> 0.
> Attached goes today's code and output.
>
> Notice that I have left my debugging logs on since I think they will be
> very useful for you to see how code behaves, and for me now that I'm gonna
> start including vectors.
>
> I desperately need some feedback now, hope you'll have some time to review
> this.
>
> https://puu.sh/xaUwS/c2f30fc275.png
> Mario.
>
> 2017-08-14 19:44 GMT+02:00 Mario Meissner <mr.rash....@gmail.com>:
>
>> The sorting function is now correctly implemented and works as expected
>> with projection structs, sorting them by distance to inhit. Some debug code
>> is included that prints the unsorted and then the sorted array of
>> projections.
>> Also much of the 'basement' for Voronoi is now ready, so now only the
>> overlaying math required to compute the average density is missing.
>> I think it can be done by tomorrow. I however am not sure at all if this
>> is what you meant when we talked about this model, I'm working a bit
>> towards unknown territory at the moment.
>> Attached goes diff.
>> Mario.
>>
>> 2017-08-11 23:46 GMT+02:00 Mario Meissner <mr.rash....@gmail.com>:
>>
>>> Hello Sean.
>>> Things got a bit messy on the previous thread, I apologize for that.
>>> I somehow managed to send emails only to myself for the last three days.
>>>
>>> I decided to start a new fresh thread and include the text of the last
>>> three emails here, as well as the newest code I have. It is a new iteration
>>> over email3 with some of today's code commented out so that it compiles and
>>> performs the 'complete' functionality I mentioned on my email2. You can get
>>> a feel of what I pretend to do next by having a look at these commented out
>>> lines of code as well.
>>>
>>> You can ignore the old thread and just reply to this one email instead.
>>> Sorry again for the mess.
>>>
>>> EMAIL 1
>>>
>>> Okay,
>>>
>>> So since stuff doesn’t seem to work very well on viewweight yet, and
>>> since we need to heavily modify existing code anyways, I decided to move
>>> back to rtexample.
>>>
>>> If we want to use Voronoi tesselation as our base model and expand it
>>> with transition vectors, many we have to rethink how we query data as well.
>>> It makes no sense anymore to just query the density at a specific point
>>> since we cannot just interpolate. Somewhere in between the two points, a
>>> sudden change of density might occur. Interpolation would asume some kind
>>> of transition, which there might not be (the value we obtain by
>>> interpolation might be way off the real value). So, instead of asking for
>>> the density at a specific point, lets give our function the whole segment
>>> so that it can correctly return the average density, or even the mass. This
>>> way the function knows where the segment starts and ends, can compute the
>>> projections and apply Voronoi tesselation to determine the different
>>> densities. Then with that info we compute the average density and return it.
>>>
>>>
>>>
>>> With rtexample I won’t have the problem of sharing a pointer to my
>>> point/vector list since I have a main function where I can do all that. My
>>> readDensityPoints() function will also work as expected here.
>>>
>>>
>>>
>>> I’ll start working on this, maybe with just 0 and 1 points for now, and
>>> hopefully make my first ‘complete’ piece of code.
>>>
>>>
>>> EMAIL 2
>>>
>>> Sean,
>>>
>>> I’ve started working on Voronoi model for non-continuous density
>>> evaluation using points. For now only 0 and 1 point works, but one complete
>>> functionality is there, which is what you requested. User inputs 0 or 1
>>> points and then program returns mass of what the ray saw when it crossed
>>> geometry. Feedback on the code I started writing to evaluate Voronoi points
>>> is appreciated and welcomed. Note that its by no means complete and
>>> probably full of mistakes. However knowing that it is the right direction
>>> is quite helpful.
>>>
>>>
>>>
>>> I think for tomorrow I can finish n-point Voronoi evaluation (especially
>>> if I got feedback).
>>>
>>> I’m also pretty confused about why my user input function doesnt work on
>>> viewweight. I’d love to get that working to go back to it.
>>>
>>> Until then I’ll work on functions to save my structs to a file and load
>>> them again.
>>>
>>>
>>>
>>> Hereby goes diff rtexample.
>>>
>>> Cheers!!
>>>
>>>
>>> EMAIL 3
>>> Hi!
>>> I've tried to clean up the code a bit more, and continued with the
>>> implementation of Voronoi points. I hit a wall though:
>>> I need to order my projections from the inhit to the outhit points. I
>>> was all happy using my bu_list to store them but now I realize that this is
>>> a really inconvenient option to manage them if I want to sort them
>>> afterwards. I thus switched to an array so that I can use stdlib qsort().
>>> Is this a good decision? WIP.
>>>
>>> As for storing the data into a file... how should I do it so that it has
>>> the shape or structure of a 'material density object'?
>>> Unfortunately today's code is not yet working. I send it anyways in the
>>> hopes of receiving much appreciated feedback.
>>>
>>> Cheers!!
>>> Mario.
>>>
>>
>>
>
Index: src/rt/rtexample.c
===================================================================
--- src/rt/rtexample.c (revisi¾n: 70059)
+++ src/rt/rtexample.c (copia de trabajo)
@@ -67,258 +67,464 @@
#include <math.h>
#include <string.h>
#include <stdio.h>
+#include <string.h>
#include "vmath.h" /* vector math macros */
#include "raytrace.h" /* librt interface definitions */
+struct density_point {
+ struct bu_list l;
+ point_t point;
+ fastf_t density;
-/**
- * rt_shootray() was told to call this on a hit.
- *
- * This callback routine utilizes the application structure which
- * describes the current state of the raytrace.
- *
- * This callback routine is provided a circular linked list of
- * partitions, each one describing one in and out segment of one
- * region for each region encountered.
- *
- * The 'segs' segment list is unused in this example.
- */
-int
-hit(struct application *ap, struct partition *PartHeadp, struct seg
*UNUSED(segs))
-{
- /* iterating over partitions, this will keep track of the current
- * partition we're working on.
- */
- struct partition *pp;
+};
- /* will serve as a pointer for the entry and exit hitpoints */
- struct hit *hitp;
+struct density_vector {
+ struct bu_list l;
+ vect_t vector;
+ point_t origin;
+ fastf_t factor;
+};
- /* will serve as a pointer to the solid primitive we hit */
- struct soltab *stp;
+struct projection {
+ struct density_point * original;
+ //point_t point;
+ vect_t vect;
+ fastf_t distance;
+};
- /* will contain surface curvature information at the entry */
- struct curvature cur = RT_CURVATURE_INIT_ZERO;
+struct contribution {
+ struct bu_list l;
+ fastf_t contrib;
+ struct density_vector * dvp;
+};
- /* will contain our hit point coordinate */
- point_t pt;
+struct density_point * user_plist;
+const int MAX_POINTS = 99;
- /* will contain normal vector where ray enters geometry */
- vect_t inormal;
+int compare_dpoints(const void *, const void *);
+int readDensityPoints(struct density_point *);
- /* will contain normal vector where ray exits geometry */
- vect_t onormal;
+/* Receives a segment and returns average density
+ Uses memory pointer to user point list */
+fastf_t segment_density(point_t inhit, point_t outhit) {
- /* iterate over each partition until we get back to the head.
- * each partition corresponds to a specific homogeneous region of
- * material.
- */
- for (pp=PartHeadp->pt_forw; pp != PartHeadp; pp = pp->pt_forw) {
+ /* If no user points available it means either no mass or default
density.
+ I will display a message indicating no points are defined so no mass*/
+ if (BU_LIST_IS_EMPTY(&(user_plist->l))) {
+ bu_log("No points available, thus object has no mass.\n");
+ return 0;
+ }
- /* print the name of the region we hit as well as the name of
- * the primitives encountered on entry and exit.
- */
- bu_log("\n--- Hit region %s (in %s, out %s)\n",
- pp->pt_regionp->reg_name,
- pp->pt_inseg->seg_stp->st_name,
- pp->pt_outseg->seg_stp->st_name );
+ /* DEBUG */
+ VPRINT("inhit", inhit);
+ VPRINT("outhit", outhit);
- /* entry hit point, so we type less */
- hitp = pp->pt_inhit;
+ /* Segment vector (for projections) */
+ vect_t segment_vect;
+ VSUB2(segment_vect, outhit, inhit);
+ fastf_t segment_len = MAGNITUDE(segment_vect);
+
+ /* Projections Loop prep */
+ struct projection * new_projection;
+ /* Not in use because we will use array?
+ struct projection * projections;
+ BU_GET(projections, struct projection);
+ BU_LIST_INIT(&(projections->l));
+ */
+ vect_t dpoint_vect;
+ vect_t paral_projection; //I need this to VPROJECT doesn't complain?
+ struct density_point * point_iter;
+ int array_pointer = 0;
+ /* Bu_calloc has given me some problems, so temporary hardcoded max */
+ /* FIXME: I should be allocating space dynamically */
+ struct projection * proj_array[99];
+
+ /* Loop through points and project them onto segment */
+ for (BU_LIST_FOR(point_iter, density_point, &(user_plist->l))) {
+ BU_GET(new_projection, struct projection);
+ /* Create userpoint vector */
+ VSUB2(dpoint_vect, point_iter->point, inhit);
+ new_projection->original = point_iter;
+ /* Project vector onto segment */
+ VPROJECT(dpoint_vect, segment_vect,
+ new_projection->vect, paral_projection);
+ /* FIXME: Check that projection actually falls INTO the segment
*/
+ /*BU_LIST_PUSH(&(projections->l), new_projection); we will use
array?*/
+ new_projection->distance = MAGNITUDE(new_projection->vect);
+ //VADD2(new_projection->point, new_projection->vect, inhit);
+ proj_array[array_pointer] = new_projection;
+ array_pointer++;
+ /* DEBUG */
+ VPRINT("projection vector", new_projection->vect);
+ }
- /* construct the actual (entry) hit-point from the ray and the
- * distance to the intersection point (i.e., the 't' value).
- */
- VJOIN1(pt, ap->a_ray.r_pt, hitp->hit_dist, ap->a_ray.r_dir);
+ /* Sort projection list based on distance to inhit */
+ /* DEBUG */
+ puts("Unordered Projection distances:");
+ for (int i = 0; i < array_pointer; i++) {
+ bu_log("Point at distance %lf \n", proj_array[i]->distance);
+ }
+ qsort(proj_array, array_pointer, sizeof(struct projection *),
compare_dpoints);
- /* primitive we encountered on entry */
- stp = pp->pt_inseg->seg_stp;
+ /* DEBUG */
+ puts("Ordered projection distances:");
+ for (int i = 0; i < array_pointer; i++) {
+ bu_log("Point at distance %lf \n", proj_array[i]->distance);
+ }
- /* compute the normal vector at the entry point, flipping the
- * normal if necessary.
- */
- RT_HIT_NORMAL(inormal, hitp, stp, &(ap->a_ray), pp->pt_inflip);
+ /* Density Computation Loop preparation */
+ struct projection * proj_iter;
+ fastf_t acc_avg_density = 0.0;
+ vect_t temp_vect;
+ struct projection * prev_proj;
- /* print the entry hit point info */
- rt_pr_hit(" In", hitp);
- VPRINT( " Ipoint", pt);
- VPRINT( " Inormal", inormal);
+ /* First projection point, we take everything from inhit to this point
+ as having density of this point */
+ proj_iter = proj_array[0];
+ acc_avg_density += proj_iter->original->density * proj_iter->distance /
segment_len;
+ /* DEBUG */
+ bu_log("First projection. Proportion %f, added %lf to accumulator.\n",
+ proj_iter->distance / segment_len, proj_iter->original->density
*
+ proj_iter->distance / segment_len);
+ prev_proj = proj_iter;
- /* This next macro fills in the curvature information which
- * consists on a principle direction vector, and the inverse
- * radii of curvature along that direction and perpendicular
- * to it. Positive curvature bends toward the outward
- * pointing normal.
- */
- RT_CURVATURE(&cur, hitp, pp->pt_inflip, stp);
+ /* Loop for remaining projections. For each point, take half the value
from last point,
+ and half the value from current point */
+ for (int i = 1; i < array_pointer; i++) {
+ proj_iter = proj_array[i];
+ VSUB2(temp_vect, proj_iter->vect, prev_proj->vect);
+ acc_avg_density += prev_proj->original->density
+ * MAGNITUDE(temp_vect) / (2 * segment_len);
+ acc_avg_density += proj_iter->original->density
+ * MAGNITUDE(temp_vect) / (2 * segment_len);
+ prev_proj = proj_iter;
+ }
+
+ /* Last portion, from the last point to the outhit point has density
value
+ of this last point */
+ VSUB2(temp_vect, segment_vect, proj_iter->vect);
+ acc_avg_density += proj_iter->original->density * MAGNITUDE(temp_vect)
/ segment_len;
- /* print the entry curvature information */
- VPRINT("PDir", cur.crv_pdir);
- bu_log(" c1=%g\n", cur.crv_c1);
- bu_log(" c2=%g\n", cur.crv_c2);
+ /* DEBUG */
+ bu_log("Last projection. Proportion %f, added %lf to accumulator.\n",
+ MAGNITUDE(temp_vect) / segment_len,
proj_iter->original->density *
+ MAGNITUDE(temp_vect) / segment_len);
- /* exit point, so we type less */
- hitp = pp->pt_outhit;
+ /* Return final value */
+ bu_log("Avg density we saw through segment: %lf \n", acc_avg_density);
+ return acc_avg_density;
+}
- /* construct the actual (exit) hit-point from the ray and the
- * distance to the intersection point (i.e., the 't' value).
- */
- VJOIN1(pt, ap->a_ray.r_pt, hitp->hit_dist, ap->a_ray.r_dir);
+/*
+Reads density points from stdin and stores them into density_point structs
+Receives the head of a bu_list of density_point structs
+and appends all points generated during the reading session to the list
+Returns the number of successfully read points
+*/
+int readDensityPoints(struct density_point * dplist_head) {
- /* primitive we exited from */
- stp = pp->pt_outseg->seg_stp;
+ /* If we are given no bu_list... */
+ if (!BU_LIST_IS_INITIALIZED(&(dplist_head->l))) {
+ bu_log("No valid head of bu_list has been provided.\n");
+ /* Maybe also check if bu_list is of type density_points? */
+ }
- /* compute the normal vector at the exit point, flipping the
- * normal if necessary.
- */
- RT_HIT_NORMAL(onormal, hitp, stp, &(ap->a_ray), pp->pt_outflip);
+ /* Local variables */
- /* print the exit hit point info */
- rt_pr_hit(" Out", hitp);
- VPRINT( " Opoint", pt);
- VPRINT( " Onormal", onormal);
- }
+ /* I count the number of times I */
+ int count = 0;
+ struct density_point *entry;
+ int correct, reading = 1;
+ char input[30];
- /* A more complicated application would probably fill in a new
- * local application structure and describe, for example, a
- * reflected or refracted ray, and then call rt_shootray() for
- * those rays.
- */
+ /* Outer loop. We come back here whenever user inputs wrong format and
until he types exit */
+ while (reading) {
+ bu_log("Please insert density points in the format: X Y Z
density_value (in g/cm3). \n");
+ bu_log("Type 'exit' to finish. \n");
+ correct = 1;
+ /* Inner loop. While user inputs points in correct format we
loop here */
+ while (correct) {
- /* Hit routine callbacks generally return 1 on hit or 0 on miss.
- * This value is returned by rt_shootray().
- */
- return 1;
+ bu_fgets(input, 30, stdin);
+
+ /* If user typed exit we need to exit both loops */
+ if (!strcmp(input, "exit\n")) {
+ bu_log("Exiting...\n");
+ correct = 0;
+ reading = 0;
+ }
+
+
+
+ /* User didn't type exit */
+ else {
+
+ /* Set up new entry */
+ BU_GET(entry, struct density_point);
+
+ /* If the input is in correct format we load it
and continue */
+ if (sscanf(input, "%lf %lf %lf %lf",
&entry->point[0], &entry->point[1], &entry->point[2], &entry->density) == 4) {
+ BU_LIST_PUSH(&(dplist_head->l),
&(entry->l));
+ count++;
+ }
+
+ /* Otherwise we dont load it and jump back to
outer loop to print usage again */
+ else {
+ correct = 0;
+ }
+ }
+ } /* Close inner loop */
+ } /* Close outer loop */
+ return count;
+} /* Close function */
+
+
+int
+hit(struct application *ap, struct partition *PartHeadp, struct seg
*UNUSED(segs))
+{
+
+ struct partition *pp;
+ struct hit *hitp;
+ struct soltab *stp;
+ struct curvature cur = RT_CURVATURE_INIT_ZERO;
+ point_t pt;
+ vect_t inormal;
+ vect_t onormal;
+
+ /* Area that the ray covers, in mm^2 */
+ const int RAY_AREA = 4; //2mm height, 2mm width
+
+ for (pp = PartHeadp->pt_forw; pp != PartHeadp; pp = pp->pt_forw) {
+ bu_log("\n--- Hit region %s (in %s, out %s)\n",
+ pp->pt_regionp->reg_name,
+ pp->pt_inseg->seg_stp->st_name,
+ pp->pt_outseg->seg_stp->st_name);
+
+ hitp = pp->pt_inhit;
+
+ VJOIN1(pt, ap->a_ray.r_pt, hitp->hit_dist, ap->a_ray.r_dir);
+
+ stp = pp->pt_inseg->seg_stp;
+ RT_HIT_NORMAL(inormal, hitp, stp, &(ap->a_ray), pp->pt_inflip);
+
+ rt_pr_hit(" In", hitp);
+ VPRINT(" Ipoint", pt);
+ VPRINT(" Inormal", inormal);
+
+ hitp = pp->pt_outhit;
+
+ VJOIN1(pt, ap->a_ray.r_pt, hitp->hit_dist, ap->a_ray.r_dir);
+
+ stp = pp->pt_outseg->seg_stp;
+ RT_HIT_NORMAL(onormal, hitp, stp, &(ap->a_ray), pp->pt_outflip);
+
+ rt_pr_hit(" Out", hitp);
+ VPRINT(" Opoint", pt);
+ VPRINT(" Onormal", onormal);
+
+ /* Now we compute the total mass this element saw while
crossing the region */
+ fastf_t mass, volume, length, avg_density;
+
+ /*Here we query the avg density of a segment */
+ avg_density = segment_density(pp->pt_inhit->hit_point,
pp->pt_outhit->hit_point);
+
+ /* Get the length */
+ length = pp->pt_outhit->hit_dist - pp->pt_inhit->hit_dist;
+ length = length / 10.0; //mm to cm
+
+ /*We also need to know the volume */
+ volume = length * RAY_AREA;
+
+ mass = volume * avg_density;
+ bu_log(" Segment length: %lf, volume crossed: %lf \n", length,
volume);
+ bu_log(" Mass the ray saw through this region: %lf g \n",
mass);
+ }
+ return 1;
}
/**
- * This is a callback routine that is invoked for every ray that
- * entirely misses hitting any geometry. This function is invoked by
- * rt_shootray() if the ray encounters nothing.
- */
+* This is a callback routine that is invoked for every ray that
+* entirely misses hitting any geometry. This function is invoked by
+* rt_shootray() if the ray encounters nothing.
+*/
int
miss(struct application *UNUSED(ap))
{
- bu_log("missed\n");
- return 0;
+ bu_log("missed\n");
+ return 0;
}
-
-/**
- * START HERE
- *
- * This is where it all begins.
- */
int
main(int argc, char **argv)
{
- /* Every application needs one of these. The "application"
- * structure carries information about how the ray-casting should
- * be performed. Defined in the raytrace.h header.
- */
- struct application ap;
+ /* Prepare user point list and let user fill it */
+ BU_GET(user_plist, struct density_point);
+ BU_LIST_INIT(&(user_plist->l));
+ readDensityPoints(user_plist);
- /* The "raytrace instance" structure contains definitions for
- * librt which are specific to the particular model being
- * processed. One copy exists for each model. Defined in
- * the raytrace.h header and is returned by rt_dirbuild().
- */
- static struct rt_i *rtip;
+ /* Prep raytracing and launch one ray */
+ struct application ap;
+ static struct rt_i *rtip;
+ char title[1024] = { 0 };
+ if (argc < 3) {
+ bu_exit(1, "Usage: %s model.g objects...\n", argv[0]);
+ }
- /* optional parameter to rt_dirbuild() that can be used to capture
- * a title if the geometry database has one set.
- */
- char title[1024] = {0};
+ rtip = rt_dirbuild(argv[1], title, sizeof(title));
+ if (rtip == RTI_NULL) {
+ bu_exit(2, "Building the database directory for [%s] FAILED\n",
argv[1]);
+ }
- /* Check for command-line arguments. Make sure we have at least a
- * geometry file and one geometry object on the command line.
- */
- if (argc < 3) {
- bu_exit(1, "Usage: %s model.g objects...\n", argv[0]);
- }
+ if (title[0]) {
+ bu_log("Title:\n%s\n", title);
+ }
- /* Load the specified geometry database (i.e., a ".g" file).
- * rt_dirbuild() returns an "instance" pointer which describes the
- * database to be raytraced. It also gives you back the title
- * string if you provide a buffer. This builds a directory of the
- * geometry (i.e., a table of contents) in the file.
- */
- rtip = rt_dirbuild(argv[1], title, sizeof(title));
- if (rtip == RTI_NULL) {
- bu_exit(2, "Building the database directory for [%s] FAILED\n",
argv[1]);
- }
+ while (argc > 2) {
+ if (rt_gettree(rtip, argv[2]) < 0)
+ bu_log("Loading the geometry for [%s] FAILED\n",
argv[2]);
+ argc--;
+ argv++;
+ }
- /* Display the geometry database title obtained during
- * rt_dirbuild if a title is set.
- */
- if (title[0]) {
- bu_log("Title:\n%s\n", title);
- }
+ rt_prep_parallel(rtip, 1);
+ RT_APPLICATION_INIT(&ap);
+ ap.a_rt_i = rtip;
+ ap.a_onehit = 0;
+ VSET(ap.a_ray.r_pt, 0.0, 0.0, 10000.0);
+ VSET(ap.a_ray.r_dir, 0.0, 0.0, -1.0);
+ VPRINT("Pnt", ap.a_ray.r_pt);
+ VPRINT("Dir", ap.a_ray.r_dir);
+ ap.a_hit = hit;
+ ap.a_miss = miss;
+ (void)rt_shootray(&ap);
- /* Walk the geometry trees. Here you identify any objects in the
- * database that you want included in the ray trace by iterating
- * of the object names that were specified on the command-line.
- */
- while (argc > 2) {
- if (rt_gettree(rtip, argv[2]) < 0)
- bu_log("Loading the geometry for [%s] FAILED\n", argv[2]);
- argc--;
- argv++;
- }
+ return 0;
+}
- /* This next call gets the database ready for ray tracing. This
- * causes some values to be precomputed, sets up space
- * partitioning, computes bounding volumes, etc.
- */
- rt_prep_parallel(rtip, 1);
+/* Returns the density value associated to the indicated point in space,
+for the material in question.
+For now the function receives an initial set of points but we will need
+to talk about how this function gets its initial information to work with.
+*/
+fastf_t old_query_density(point_t query_point) {
- /* initialize all values in application structure to zero */
- RT_APPLICATION_INIT(&ap);
+ /* Density point list */
+ struct density_point * dplist;
+ BU_GET(dplist, struct density_point);
+ BU_LIST_INIT(&(dplist->l));
- /* your application uses the raytrace instance containing the
- * geometry we loaded. this describes what we're shooting at.
- */
- ap.a_rt_i = rtip;
+ /* When no points provided we use this as fallback value */
+ fastf_t DEFAULT_DENSITY = 8.0;
- /* stop at the first point of intersection or shoot all the way
- * through (defaults to 0 to shoot all the way through).
- */
- ap.a_onehit = 0;
+ /* Set up density_vector list */
+ struct density_vector * dvlist;
+ BU_GET(dvlist, struct density_vector);
+ BU_LIST_INIT(&(dvlist->l));
- /* Set the ray start point and direction rt_shootray() uses these
- * two to determine what ray to fire. In this case we simply
- * shoot down the z axis toward the origin from 10 meters away.
- *
- * It's worth nothing that librt assumes units of millimeters.
- * All geometry is stored as millimeters regardless of the units
- * set during editing. There are libbu routines for performing
- * unit conversions if desired.
- */
- VSET(ap.a_ray.r_pt, 0.0, 0.0, 10000.0);
- VSET(ap.a_ray.r_dir, 0.0, 0.0, -1.0);
+ /* This point is the origin for all density_vectors,
+ and holds origin density value of material */
+ struct density_point * origin;
+ BU_GET(origin, struct density_point);
- /* Simple debug printing */
- VPRINT("Pnt", ap.a_ray.r_pt);
- VPRINT("Dir", ap.a_ray.r_dir);
+ /* If point list is empty, no points, we assume homogeneous default
density.
+ I set the origin point to default in this case. */
+ if (BU_LIST_IS_EMPTY(&(dplist->l))) {
+ origin->density = DEFAULT_DENSITY;
+ VSETALL(origin->point, 0.0);
+ /* dvlist will remain empty */
+ }
+ else {
+ /* If there is at least one point, take first point and make it
origin. */
+ BU_LIST_POP(density_point, &(dplist->l), origin);
- /* This is what callback to perform on a hit. */
- ap.a_hit = hit;
+ /* While there are still points, draw a vector from origin to
point
+ and store it in list. */
+ struct density_vector * new_vect;
+ struct density_point * point_iter;
+ while (BU_LIST_WHILE(point_iter, density_point, &(dplist->l))) {
+ BU_GET(new_vect, struct density_vector);
+ VSUB2(new_vect->vector, point_iter->point,
origin->point);
+ new_vect->factor = point_iter->density /
origin->density;
+ BU_LIST_PUSH(&(dvlist->l), new_vect);
+ BU_LIST_DEQUEUE(&(point_iter->l));
+ }
- /* This is what callback to perform on a miss. */
- ap.a_miss = miss;
+ }
- /* Shoot the ray. */
- (void)rt_shootray(&ap);
- /* A real application would probably set up another ray and fire
- * again or do something a lot more complex in the callbacks.
- */
+ /* We draw the vector corresponding to the queried point */
+ vect_t query_vector;
+ VSUB2(query_vector, query_point, origin->point);
- return 0;
+ /* After this, we will always have at least one point, origin.
+ If no more points are present, we use this point's value for
+ homogeneous density. */
+ if (BU_LIST_IS_EMPTY(&(dvlist->l))) {
+ return origin->density;
+ }
+ else {
+
+ /* We now dequeue our vector list and fill in the array of
projection values */
+
+ vect_t paral_projection; //I need this so VPROJECT doesn't
complain?
+ vect_t orth_projection; //Orthogonally projected query_vector
onto density_vectors
+ /* Set up
contribution lists */
+ struct contribution * contrib_list;
+ BU_GET(contrib_list, struct contribution);
+ BU_LIST_INIT(&(contrib_list->l));
+ /* Variables for the loop */
+ struct density_vector * vect_iter;
+ struct contribution * new_contrib;
+ fastf_t contrib, scalar_proj, proportion;
+
+ /* Loop through vectors and build contribution list */
+ while (BU_LIST_WHILE(vect_iter, density_vector, &(dvlist->l))) {
+ VPROJECT(query_vector, vect_iter->vector,
orth_projection, paral_projection);
+ scalar_proj = MAGNITUDE(orth_projection);
+ proportion = scalar_proj / MAGNITUDE(vect_iter->vector);
+ BU_GET(new_contrib, struct contribution);
+ /* In 'scalar_proj' proportion, our contribution value
will be the density of dv,
+ which is original * factor. The 'rest' is original
density */
+ contrib = origin->density * vect_iter->factor *
proportion +
+ origin->density * (1 - proportion);
+ new_contrib->contrib = contrib;
+ new_contrib->dvp = vect_iter;
+ BU_LIST_PUSH(&(contrib_list->l), new_contrib);
+ BU_LIST_DEQUEUE(&(vect_iter->l));
+ }
+
+
+ /* Now go through contributions and do work on it
+ For now take average */
+ struct contribution * contrib_iter;
+ fastf_t acc_contrib = 0.0; //Accumulated contributions (total)
+ int numContribs = bu_list_len(&(contrib_list->l)); //Amount of
entries
+ while (BU_LIST_WHILE(contrib_iter, contribution,
&(contrib_list->l))) {
+ acc_contrib += contrib_iter->contrib;
+ BU_LIST_DEQUEUE(&(contrib_iter->l));
+ };
+
+ /*DEBUG
+ VPRINT("query_vector", query_vector);
+ VPRINT("orth_proj", vector_orth_proj);
+ bu_log("scalar_proj is %lf \n", scalar_proj);
+ bu_log("proportion is %lf \n", proportion);
+ */
+
+ return acc_contrib / numContribs;
+
+ }
+
}
+int compare_dpoints(const void *a, const void *b) {
+ struct projection *x = *(struct projection **)a;
+ struct projection *y = *(struct projection **)b;
+ return x->distance - y->distance;
+}
+
/*
* Local Variables:
* mode: C
------------------------------------------------------------------------------
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