Day 44 & 45

DAY 44:
I continued working on the ripple effect in POPS. I thought it will be nearing completion. However a problem cropped up yesterday. The method which Mr Steven showed to me, regarding pre-fracturing the pieces and then in POPS, choose the emission type as Prim Center(Ordered) doesn't work. If I pre-fracture my terrain, there will be the pre-fracture lines and the grid-like lines as well.

And if I bring that into pops, POPS will get confused and the result is totally crazy.

I asked Charles for help and he tried projecting the crack lines on to a clean grid. It worked, but I will lose the terrain details.

Mr Steven told me to move on and try another method. I decided to use the method which originates from Mr Ron and it was further worked on and edited by the people on odforce.

http://forums.odforce.net/index.php?/topic/13709-copying-problem-weird-rotation/

What this does is, I pre-fracture the geometry, add a point in the center of each chunk, run the bunch of center points into POPS. There is also added angular velocity for rotation purposes.

Then the points, particles are copied on a VOPSOP. I also touched on shaders a little. And below is a simple render test.( Not the exact terrain scale )

DAY 45:
Today, I wanted to finish a low-res simulation to show Mr Steven. And I managed to did it. I spend the whole afternoon rebuilding the VOPSOP method. Then there was some crazy issues with the rebuilding of the VOPSOP. The pieces do not turn! And I did exactly the same thing. And there is angular velocity too.

Anyway, the problem was, it should be " instead of '. And I forgotten to connect a single attribute correctly. Anyway, the problem was fixed. I sent the playblast videos to Mr Steven and he said, the pieces seems to fall too fast, and the ripple is still very tight.

That's the end.

Day 43

Today I continued with the ripple effect. Mr Steven showed me 2 files which describes what I wanted, how do I copy the fracture pieces onto the particles network simulation?

First he showed me a system which uses copy stamping:

What this does is he uses an expression to delete the pieces and then uses copy stamping to copy it onto the points.

It somehow worked, but there was this weird rotation that was going on. I emailed Mr Steven again, asking him if he knew what the problem was.

He told me that the pieces were copied to the velocity vector hence they rotate in a weird way.


He then showed me another method which was very very very much simpler to understand, and simpler to do.

At first, I couldn't even believe that it could be done this way.


Anyway, it worked perfectly. Mr Steven then asked me to test out the simulation with a grid size similar to my terrain, to determine roughly how many scatter points is needed. I tried a grid with 500 rows and columns. The cache file for the simulation amounted to 16 GB. And the simulation became super low. Maybe that was the limit.

After that, I went ahead into using my actual terrain. I realised that, given the severe unevenness of the terrain, I had a lot of trouble trying to group the particles for the ripple to throw it back down. I tried many methods, I tried using a bounding object as the bounds for the grouping, but it didn't really work that well, some particles still seep through resulting in crazy, stretching pieces. I tried setting that object that I am using for the bound to a collision object, and the problem with that was the bounce was super sensitive. Resulting in the particles flying all over the place.


Hence, I decided that the easiest solution for me to fix it was to flatten my entire terrain. Get rid of the mountains and stuffs. I will do it tonight.

Anyway, I would like to thank Mr Steven for the amount of help and help files he provided me during this past few days.

I guess I got to finish quick, If not there will not be anything new to show him tomorrow.

And there was another method of copying that I posted on odforce because I would like to know how to do it.

http://forums.odforce.net/index.php?/topic/13709-copying-problem-weird-rotation/


And I also finally came up with a production schedule. And after doing it, I realised that I still have a lot more work to do. Got to pull my socks up though.

Day 42

Today, Mr Steven provided his version of my file to me. I looked through it and the result looks much better than my own version. He edited my network, he created a random force for the ripple effect using a expression.



He increased the upward force and also the downward force, to create that "up down" effect.

This was how it looked:



Mr Steven also told me that I should increase the upward force and add rotation values to the pieces.

I managed to accomplish both tasks:

1: Increase upward force

To increase the height of the ripple, I played with both the upward force that throws it up and also the downward force that throws it down.

2: Add rotation values

I did a group of the pieces in mid-air in SOPS. I then applied a primitive sop to the group with a random rotation expression.



And it looks decent I would say,



Mr Steven also told me that I may need a deformed ground for collision and up till now I haven't got it to work. And also the pre-fracture technique.

Day 41

Today, I feel that I accomplished quite a fair bit today. I managed to complete the ice pops tutorial without much problems. And I also managed to tweak the settings in pops to look like a ripple. Now all I left is knowing how to copy the pre-fracture pieces to each point.

I tried a couple of ways:

First, The ice pops tutorial way:

And this was the result:



It works though, but the geometry looks weird. Not knowing why, I moved on to another method.

Second, Mr Ron's vopsop copy method during FYP:

I tried Mr Ron's vopsop method that he taught me during FYPJ. This was the result:



And this doesn't work for some reason. Okay time to move on.

I went back to the first method. Thinking something is wrong, I went back inside pops and started playing around with the emission type.

I stumbled upon Prim Center(ordered) and realised that it works.



And this was how it looks after being copied:



And this was how it looks when I did a playback:



It kind of worked, so, I decided to start playing around with the settings on how it should react after it come back down to its original position.

At first I thought collision will be able to solve everything, hence I spend a long time tweaking it. I made it bounce first, then stop. Bla bla.. However, after that I realised that it will not work. First the bounciness is too difficult to control. Secondly, the direction of it bouncing is difficult to control also.

I decide to come out of pops, do a group of the points in mid-air and do a point jitter. I tried jittering them when they went back to their original positon and it looked weird. I also consulted Steven on a couple of issues. Like, what if I wanted to pre-fracture my geometry and this method may not even work out.


I ended like that.

Day 38

Okay, so I am officially behind time. Mr Steven came in today and told me that my dops simulation is still not there yet. I mentioned to him that my scene is getting so so heavy now that it crashes every now and then.

He told me that there were a couple of issues. My fractured pieces looks more like they are stretching rather than breaking. And I agree with him. He then told me that instead of running simulations, why don't I try it using pops. Like add a point in the center of each piece and then copy each piece to each point.

Luckily, I did something like that before during FYP. So maybe I would have a head start somehow.

He directed me to a pdf and told me to start looking at it.

I spend the whole day playblasting files and looking at houdini crashing.

Day 37

Today was a day where a lot of cooking occured. I re-tweaked my simulation until I am sort of happy today and we got news that Steven will be coming in tomorrow. I tweaked my simulation until I do not know what else can be tweaked.

But anyways, I decided to increase the scatter points for the simulation to test it out and also to let Steven look at it tomorrow so there is more variety.

I have a couple of playblast that I rendered, but they are all in wireframes.

That means that more ropping needs to be done. And the ropping takes so long. I will stick to the current simulation settings for now and see what Steven says tomorrow before I proceed further.

Day 36

Today I continued with the ripple effect. I broke up my terrain as what Steven told me. And this was how it looked( after pre-fracturing it )



I started working in the center impact portion. And that portion also happens to have the most scattered points on it.

I re-did my entire system from before. And after doing it, I realised that after the ripple occured, my fractured pieces still continue to bounce.

Not knowing why, I consulted Eric for advice. He told me that the most logical reason he can think of is because I added a force to force the pieces up and I also added another force to force the pieces down. Hence, that results in the bouncing in mid-air effect.

He told me to try to work simple if I wanted to work with groups.

Hence, I sat down thought through how I wanted it to be.

And suddenly I realised, since I already defined color inside dops, why don't I use that group to force the pieces to go up and then add a gravity node and force the pieces down after that? It may sound the same, but the group which is created based on color takes in the pieces based on the color value. Which in this case is driven by the a torus-like shape which is animated against time. Hence, some pieces which are affected by the group will go out of the group once they lose their color values. Hence, I could have more control.

I proceed on in that direction. For the gravity force pushing the pieces down, I went with the same expression that groups the pieces based on their position data.

And I will post some test videos below.

Anyway, after making sure that looks decent, I proceeded on with the second layer of the terrain.



I realised that using the same settings for the smaller terrain portion will not work for the bigger one. More settings needed to be tweaked. Or maybe its because of the piece size. Who knows?

Anyways, I played with the glue value, put that to 0. I changed the rotational stiffness and the friction.

I also increased the force that pushes the pieces upwards and decrease the forces that pushes the pieces downwards. I just played with it and hopefully I could show Steven something decent if he comes in tomorrow.

Day 35

Today, I continued with the ripple effect. I showed Mr Ari my new camera angle and he said it will not work out for him. As the turn is too sudden.

Hence, back to square one. I went back and re-did all of the timings of the camera work in my previs. I managed to finish it today. I then set up the ripple effect file hierarchy from the previous file.

I only can manage to finish it just before dops. Will continue tomorrow.

Day 34

Today we were caught on camera!





Cool! That was a nice start.

Back to work, today I went in and realised that my renders were so screwed up. I prepared 3 renders for today and only 1 managed to finish. God.

Anyway, I emailed Steven with that render and also the image which I rendered in HD with glow and stuff.






And he told me that my simulation needed a lot more work. Things such as the particle trail, the front flickering of smoke etc.

He advised me to focus on my shattering effect first instead.

I went with his advice and continued on my shattering effect.

I found that my existing camera angle was kind of cheesy and so I asked Bryan
for some advice.

He gave me some ideas on re-positioning my camera angle and it looked much better than my previous one.

I am not sure if I am allowed to change camera angles halfway through production.
And I know that I am working in the really wrong way.

But anyways, I decided to change it as it will look much better if I put that in my reel.

I spend the whole day tweaking the camera angle and setting up the shattering hierarchy I had in my other file.

I haven't got a chance to playblast the new camera angle. Will do when I have the time. But trust me, is much much nicer than my previous one.

Day 31

Today, I continued doing my meteor shot. Hopefully today will be my last and final day tweaking the shot. I realised my render for my meteor trail with motion blur is still going on. It took 22hours( and still counting ) and it is still has 7 frames more to go. I am rendering 72 frames by the way. Okay, so I will put that aside.

I continued with the glow effect for my meteor. I managed to get it looking like this:


After finding that it looked quite decent, I proceeded on to rendering the meteor rock with smoke. And it looked like this:

Below is the result with a couple of iterations:






I found that it looked pretty decent. Now I proceed on rendering it at HD 720.



The renders from yesterday aren't done yet. Hence, I will upload the renders on Monday. Meanwhile, I will pass in the render with the new glow geometry and also render that at HD 720 with motion blur.

Day 30

Today, I continued with the meteor. I consulted Mr Ari with regards to the glow of the meteor and the flickering of the smoke. He told me that I could do the glow in post or add a geometry light to the rock. I could then add a glow shader to the geometry light to further enhance it.

For the motion blur, he told me the problem that I had before with the motion blur was because I didn't increase the pixel samples in my mantra. After he helped me increase the pixel samples, The motion blur artifacts went away. ( But the render time increase by 3 times I think )


Above is a incomplete render of smoke with the motion blur. I couldn't wait for it to finish. Anyway, I couldn't visualize the smoke flickering now as it is not showing in the viewport. Let's hope motion blur could at least do something to fix that problem hopefully. After that I moved on to do the glow effect for the rock. I just messed around with the glow shader and the light intensity of the geometry light.

After that Charles gave a very interesting class about expressions. The class was more directed towards using expressions to do animations of objects. Like for example, animating objects using sine, cosine functions etc. That was all about what I have done today. Hopefully more tomorrow.

Day 29

I am officially at a crossroad now. Should I stick with what I am doing now, which is continue using the FXtool Heavy smoke or jump on to smoke simulations directly.

However, the down side of continuing using the FXtool is that, it doesn't provide much control and not really anyone here at SESI knows much about it. And I am so officially stuck.

If I jump on to smoke simulations directly, I have to learn starting from the basics and I wonder is it even worth the time to do that. Given that this shot is not my main shot.

Anyway, since I am so stuck, I went to watch some tutorials on smoke simulations just in case. Before I started on that, I dropped Steven, Mr Ron an email asking them for help. Hopefully they will reply. Odforce also didn't provide much help for me.

I watched a tutorial by cmiVFX on dust and smoke simulations. And after that, I went and did some test, like literally just playing around.

Suddenly, I saw that Steven replied my email, in the email he told me that he solved my problem and that was how he did it.

The before effect:


The after effect:



The way he did it was that he read in the alpha information from the metaballs in SOPS into VOPS. He then multiply that information with the calculated density from the shader itself. So I officially solved my problem. I am ready to move on. Thanks Steven for your help.

Next, I asked Steven about how did he managed to read in the alpha information from SOPS inside VOPS without doing any referencing at all. He told me that, creating a variable in VOPS that has the same name as a variable in SOPS will result in the variable data in SOPS overwriting the variable data in VOPS. Hence, that was how he could read in the Alpha information from SOPS by just literally creating the same "Alpha" variable in VOPS that is found in SOPS.

I also asked Steven about how do I solved the smoke flickering problems that I had. He told me that for me to do that, I could let the particles which are supposed to die, live longer and fade them out gradually instead of just letting them die.

I will so definitely give that a try tomorrow.

Day 28

Today, I continued working on the meteor trail. This time I am working on the lighting of it. A couple of versions:


Version 1: With heavy environment lighting.


Version 2: Tweaking environment lighting and changed color of sunlight.


Version 3: Overall lighting made brighter.

I then asked Mr Ari for comments on my overall scene.

He told me there were a couple of problems that needs to be worked on:
1- The meteor trail should spread out more instead of it being almost a straight line.
2- The tip of the smoke( which is supposed to be fire ) isn't hot enough. Glow could be added in to enhance it.
3- The smoke trail's density is too consistent. Allow the smoke to fade off at the back.
4- The smoke flickers too much. It should be more of a static thing after the meteor is "lit".

Just in case:

Below is my first render with some basic lights:




I started working on problem 1. And I solved it I think. Below is how it looks:



Next, I moved on to problem 3:

I managed to get some alpha in my scene by adding a color node inside pops and adding an alpha ramp to it.

I managed to get the viewport alpha to work and it somehow looks like this:



But the problem is when I render this out it looks exactly the same as before.

I therefore suspect that the shader is the problem. I went into the shader and did some random test.

I added a spline ramp to the surface alpha channel inside the shader, hoping it will work.



But no...It didn't.

Can anyone help me?

Day 27

Today, I made a decision. I will spend 2 days to tweak shot 1 and then pass it on for review before render. The past few days I am so not doing anything constructive.

Okay, so for today, I went and tweak the heavy smoke FXtool to suit more of my production needs. I turned down inherit velocities, mess around with the birth rates, went inside the network and started to do some exploring. As I mentioned a couple of days earlier, I managed to found a way to change the color of the smoke. I just played around with that and I am trying to create some alpha at the sides of the smoke. Still haven't figured that out yet. I then did a test render:



Next I placed arealights into the scene to light up the smoke. The result? Smoke that looks like smoke.
Below are the renders:



I also tried adding motion blur into the smoke.

Crazy motion blur( 15 ):



Crazy motion blur( 5 ):



And my initial test days ago:



I decided to render out a video and ask Steven to look at it for comments instead of just showing him a static frame. Now rendering.

Day 26

Today I started tackling those problems. First I went into the ripple fracture. I increased the gravity and soon after that effect started to show up a little.

I started tweaking it. However I realised that after I tried to make the simulation longer, my fractured pieces started moving towards a particular direction. I suspected it is this problem:




The slanting line. That line is suppose to be the velocity vector. I guess that all the pieces are moving along this velocity vector direction.

I consulted Mr Ziggy on this problem. He told me that, the problem is that my fit expression that creates the velocity.



My fit expression is giving this weird result. Mr Ziggy then did a step by step guide in showing me how it could be fixed.

Just by doing this is was fixed. How simple was that.



What is the difference is that, instead of refitting the values into user defined, refit them into per units. Then to increase the values use a multiplier. That way it will be much easier to control the velocities directions.

For today, that was what I did for the ripple fracturing.

I then moved on to tackle the meteor trail. I found a post on odforce showing how to create a ramp color for the smoke. I applied that and it looked like that:

I will continue to work on it.

That is all.

Day 25

Today, I continued doing the ripple effect as usual. Actually, I didn't really do much today. The computers were letting me so so down. I do not know why my scenes are much laggier today, compared to the day before, even with the same scene. I had to restart computers around 5 times so far. God, maybe there was really something wrong with my scenes.

And my latest versions of my files, the fracturing pieces doesn't break! God, after restarting the computers many times and frustrating myself with the killer lag, I just realized that at around 4pm. I quickly rushed to get the previous file versions( luckily, it works ).

I quickly did fracturing test for a different number of scatter points, 100, 500, 800.

I hope they can finish before Steven reaches.

Anyways, I didn't slack of when I was waiting for the simulation to cook. I went and did my meteor trails. I went to odforce and saw many threads. The one that I did initially was following Miguel's meteor tutorial. ( I didn't get to see the tutorial, just the file ) He was using sprites to create the trail. When I did it and tried to add motion blur to enhance the effect, it did not look good at all. I wonder how they did it. I have seen some people who followed his tutorial and produced decent results. But there isn't any files from them. Some I saw are:

http://forums.odforce.net/index.php?/topic/7353-how-to-render-color-on-sprites/page__hl__meteor__fromsearch__1

http://forums.odforce.net/index.php?/topic/5414-meteor-impact/page__hl__meteor__fromsearch__1

http://forums.odforce.net/index.php?/topic/5377-meteor/page__hl__meteor__fromsearch__1

I found a post which was discussing about the FXtool Heavy smoke in Houdini. I suddenly remembered that that tool produces quite decent smoke. I went and played around with the parameters and indeed it does. But there may be some problems which I have not notice....



I parented a sphere to this "smoke heavy" system.

Steven went through with me both my fracturing system and my meteor trail. He told me a couple of things that needs to be improved.

1- The fractured pieces should be affected by gravity and be pushed down instead of just staying put after the ripple.

2- The effect is too fast. And, a way that I could tackle the problem of simulation time and scale is to break the terrain up into different set of pieces. Then using different scatter points, pre-fracture the different pieces.

3- For the meteor trail, there has to be some sort of ramp color instead of a flat color.

4- Do more research.

I will tackle this problems from tomorrow onwards.

Day 24

Today, I continued on the ripple effect simulation. I took note of what steven mentioned to me regarding the whole simulation I showed to him.

Things he said:
1- It feels a little slow for the ripple
2- Size of each piece. And a reference for that.

First I tried to improve on the effect itself until I was satisfied. I created 2 sets of additional forces on top of the ripple effect.

1- A force that creates the upheaval effect, throws the pieces further up in the air
2- A force that brings the pieces affected by the first force down, it works like a gravity force.

I do not have the playblast with me now, due to some technical issues, but I will get it out and show it to Steven when he gets here tomorrow.

After that, I rebuilt the entire system using the terrain I did yesterday. The scale I would say is at least 15 times bigger than what I was working with before. Hence, the forces and velocities have to be much greater. Below is the scale reference of my terrain with regards to a default human scale( The model was not done by me, it was done by Mr Douglas, I am using it only for comparison intentions. Credit and Thanks to Mr Douglas)



This is the near shot.( This is not my camera angle)



This is the far shot( This is also not my camera angle )

And below is the piece reference I was intending to achieve:



I looked through the trailer on Thor which has the effect I was trying to re-create. God, their pieces were so small. ( If you compared the piece size to Thor himself. ) I wonder how many points they used, or maybe they cheated?


However there were some problems:
1- To even reach that piece size is already insane( scatter points is at 25 000 )
2- I do not know how am I going to simulate with 25 000 scatter points. 3 000 already takes so long.
3- I'm having issues with the size of my ripple and the pieces breaking up.


I would bring that up to Steven when I see him tomorrow.

That is all for today.

Day 23

Today is the first day after the long Independence Day holiday. The long holiday wasn't as fruitfully spend as what I was hoping for. But anyways, back to the important stuffs. Today I took a look at Mr Michael's file. The method he was using for his fracturing was different. And the results seems much better than what I was working on for the past 2 weeks I think. Anyways, after that, I went into modeling of the terrain using Bryan's heightmap otl he created during FYPJ.

It was my first time painting heightmaps in photoshop and the results was kind of crappy.



Can you even tell what this is?

No I guess. But this was actually my first version.

After much variations:




I gave up, I decided to take a existing heightmap and edit it in photoshop. This is what I found.




This was how it looked and after much work, the terrain which I was kind of satisfied with it.




Yah, I know, there isn't much difference. But I do not need much details on my terrain anyways. And now I am trying to rebuild Mr Michael's system using this terrain. Still no luck, hope it works!