Day 18

Today I would say was the busiest day of my entire 3 weeks at SESI. Maybe it was a good thing after all. Anyways, we came late today, we sat down and I continuing my ripple effect collision. I just realised something after a short while. The attributeTransfer node which I put earlier destroyed my velocity I create using the point sop. God! I deleted the attributeTransfer node and that gave me a much better result.

Anyways, Zack conducted a class for us today, It was on the basics of rendering. He went through all the different render engines and what do they do. And how do we optimise them.

First up, MicroPolygon Rendering.

Ways to optimise,
- Tweak min/max ray samples first before anything else. Because they are much less computational heavy.
- You could also tweak Shading Quality Multiplier.

Ray-Tracing Rendering.

- Renders polygon rendering the best.( Not nurbs, displacements )

Ways to optimise,
-Under dicing, Rayshading Quality.
-Ray tracing Acceleration
-KD- Tree
-KD Tree Memory Factor, shortens viewing tree time.

Physically Based Rendering.
-Better results, smoother shading, softer shadows, realistic lighting, bouncing lights.
-Volume step size is to improve rendering of volume objects.

Ways to optimise,
- Lower color limit to remove white dots on render.

Under render tab:
- Tile size( Large tile size better quality )
-Pixel Samples, Controls overall render quality for all rendering engines.

Light sampling Quality acts as a sampling multiplier to the Pixel Samples under Mantra.
Hence a 12 for light sampling Quality and a 4 for Pixel Samples in Mantra will result in a 48 sample ratio for the overall sampling rate.

Depth of field, camera F-stop(Smaller value more blur).

Motion Blur, shutter time controls motion blur, turn on geometry velocity blur for blurring of particles, etc.

Rendering wireframes:
- Create facet node under object, turn on UNIQUE POINTS
- Under Output, create wren node and there you go!

Render passes:
- Creates render passes using takes. Add a take, and select parameters to be include/exclude in the take.


Okay, after lesson ended, we went for lunch.

After lunch, I continued with my ripple effect fracturing. I will update that later, but for now, I will explain on the meteor trail I am working on.

I am supposed to create a meteor trail for my rock as it crashes down. I do not want to involve pyro simulations as I do not want to waste time trying to learn it from scratch. However, I found a thread which Miguel posted. He created his meteor trail using sprites and I decided to use that method. The way he did it is just messing around with the color of the sprites. Below is a render with motion blur.



I got no idea on how it will look if I include in the rock, maybe horrible. But I will give it a test within the next few days.

Below is my simple hierarchy:



Okay, now I will move on to my ripple effect collision. I am officially still stuck on that problem I had since yesterday. At least now I knew I could group it with color(thanks to Corinne) And thanks to Eric too!

So I am still messing around with it. Do not have a image to show how it looks but look forward to it!

It is slightly better than yesterday I would say personally!

Day 17

Today, I admitted. I slacked. Anyways, today, I went back into my simulation scene. I asked Eric about the velocity in Y problem which I had yesterday. His advice to me was, instead of computing velocities based on position which is not working, how about generating velocities using an expression?

Below is what it looks like:




And when I compute that in my dops, the simulatiom looks much better than the day before. That is how it looks:



I just messed around with it for somemore and then I realised that when the simulation is happening, there are crazy geometry pieces flying around. Weird. Anyway pause for now because Jeff Wagner has another demo to show us. And stop, my lips are so sealed.


The demo finished at around before lunch time. I went into my email and realised Mr Steven sort of approved my idea 1. He told me that I could start modeling. Yeah!

I then went to look up some references and ways on how to create the meteor trail while my thing is simulating. And I didn't manage to do a nice one, so I will not post here. But just to let you guys know, I found a way of doing the meteor trail using sprites instead of pyro but however I had some problems with the bluring of the sprites. And I decided that I will call it a day.

Day 16

Today, we came into SESI as usual, I think I am going to skip this line from tomorrow onwards. I started my day by resuming the simulations caching from yesterday. While I was doing that, I was staring at my rock shader.

After awhile, Zack started his class on lighting. He covered basic lighting principles. He also covered most of the lights in Houdini. He also taught us about the IPR render view in Houdini. After that, he taught us more on 3 point lighting.

He told us that whenever you start lighting a scene, always use the camera as a reference, as that is where the viewer will see everything. He also told us about some aspects of the lights. For example, spotlight renders faster compared to point light( which is equivalent to 6 spotlights ) Spotlights uses cone angle to generate depth map shadows. And depth map shadows doesn't work with IPR render.

About 3 point lighting,
Keylight - Area light. Reason being it provides with softer shadows. And area light in Houdini is not as computational heavy as compared to Maya.

Fill Light - Environment light. Reason being environment light gives the subject more bounced light around. For example, sun is our keylight while the sky is our fill light. That works around the same way as this concept.

He also talked about the option normalise light intensity to area, and that means that if the area light is closed to a particular object, the light intensity will be normalise so that overexposure will not occur on the object and at the same time underexposure.

After that I continued with my rock shader:

Below is the look. I am quite satisfied with the look. I wonder if I still need to tweak? Maybe.




Anyways, this rock is a much lower resolution mesh compared to the previous. And with Charles help, I managed to add another set of displacement on the rock itself. Hence, getting more detail on a lower resolution model.

Below is my hierarchy.





And regarding the ripple simulation, I managed to make it break a little. But I realised a problem which is that, when I tried to create velocity for my simulation, the Y velocity isn't created. Maybe because my object is nurbs. I think I will fix the problem tomorrow and hopefully have a flipbook of it here tomorrow. So close maybe?

Got to go to the pharmacy later to get medicine, later!

Day 15

We came in to SESI like always. I started working on the ripple effect that as a guy on odforce gave me some help on the problem I faced last week. After doing what he told me, I managed to get it to break apart! I did more tweaking, until I am satisfied, I moved on to a bigger and higher resolution grid and started replicating the effect. It seems to work but it takes ages to cook. God, the bad memories during final year project. Anyways, while I was letting it cook, I continued with my previs, I came up with another idea though. Sorry, I didn't post up the previous previs, but I will do it later with the new idea. I am planning to email Mr Steven tonight regarding the new previs and see what he says.

After finishing the previs, I went and did a little shader work. Actually, I didn't do much. I just went in and change the colors and did some minor re-editing of the network. Below is how it looks:



I hope it looks better. I am trying to overlay another set of displacement over the existing rock. I got no idea on how to go about doing it. Let's hope I could ask someone tomorrow.


And that more or less wrap up what I did for today. Videos later!

Day 14

Today was the day Mr Steven and his wife brought us to the factory outlet. They came and picked us up at around 9am. They then drove us to a Vietnamese food outlet to get some breakfast. The ham and cheese croissant, Heavenly. After that, It was a long drive for around and 1hour plus to reach the outlet which was at Cabazon, CA (Palm Springs/LA Area). The area I heard was near a desert or something like that. But anyways, the view was very good. I could see large mountains around. The only downside was it was extremely hot and the air extremely dry.

Mr Steven and his wife helped us to get the vouchers book for the outlet store and after that we are all geared up for shopping. I will not go into the details though. But we shopped a lot a lot.

We finished shopping around 4.30pm and we left the outlet at 5pm. It was then an 1hour drive to a Penang food restaurant. When we arrived, we ordered lots of food. And we started digging in soon after. The food was very good. After the meal Mr Steven made the payment and he and his wife said that this meal was on them. Thanks for the good meal!

After the meal, we went to a Hong Kong grocery supermarket to buy groceries. There were many things there, but they weren't that cheap. In the end we bought a couple of stuffs that cost us 60 over dollars. We saw dim sum also. Very good!

After that it was another 45mins ride home. And once we got home, we bid our goodbyes and that is how the day ended.

Pictures!

Day 13

Today we woke up at 6plus to go to SESI. Gosh. Today we are suppose to attend the VES(Visual Effects Society) conference in Renaissance Hotel at Hollywood. Ms Aliza and Mr Ari will send us there. We met them at SESI around 7.45am. We then made out wait to their cars and they drove us there. We arrived at around 8.45am. Ms Aliza parked her car inside the car park near a mall. We then made our way to the location.

The place was nice. Very grand. We then went into the ballroom which held the conference for Side Effects. We also grabbed breakfast at the back of the ballroom. Hotel style food. Soon after, they started opening up for the conference. There were a fair amount of companies at the event. As it was more of a recruitment event, there were many people there, handling out their resumes and showing their reels on their ipads. I approached many studios asking just for more general info. And I would say, The smaller studios aren't really geared up for Houdini in their studios. But I heard from some of my friends which approached the more popular studios, that they had houdini built into their production pipeline, but maybe not at a large scale.

Anyways, the most popular booths with many people queued up for were, Disney Animation, Sony Pictures, Digital Domain, MPC and etc.

After walking around, we decided to head out to Hollywood and try to take a picture of the Hollywood logo ontop of the hill. After many tries and quite long walking distance under the hot sun, we managed to get a clear view of it at the shopping mall next to the hotel. We took pictures and walked around the shopping mall. The shopping mall was much bigger than NordStrom though. After we had lunch we headed out to walk the Hollywood Walk of fame. We was practically staring at the stars on the pavement and not looking at any shops. We saw a fair amount of famous celebrities. After that we headed back to the hotel and helped the guys move the stuffs down to the loading bay. We then helped to load the stuffs(Computers, CPUs, cables) onto Ms Aliza's car and then Mr Ari drove us back to SESI.

We then went for dinner at Nordstrom( as usual...) We went home after that.

Now...

PICTURES!

Day 12

Today, our toilet choked in the morning. Hence, I had to wait until we arrived at SESI before I could even use the toilet. Gosh, what a day to start. We arrived at SESI and helped Aliza moved the computers to her car for tomorrow's VES event. We got to reach SESI by 7.30am. Can you believe it?

Anyways, I started re editing my previs. I will post the updated video here once I get home later. But below are a couple of screen shots.







Okay, I will explain. Steven told me that I should add spheres on the wave itself so that it will be easier to visualise. I could also use the spheres for the transition effect. However, when I tried it, it was too heavy as what I am doing is that I am grouping the top points of the wave and copying spheres to it. I do not know if that is the best way of doing things though, but it didn't work.

I thought of another way and it is by using the same group but emitting sprites instead. I managed to did it successfully as shown in the screenshot above. I suddenly thought of a idea for the transition while I was thinking of how to do the transition using the sprites.

My idea was how about as the camera is panning up, a debris flies towards the camera, knocking the camera before cutting to black. I do not know if that will work though. I will compile it into a video and send it to Steven tonight and see what he says.

After so called "completing" my previs, I moved on to do the ripple fracturing effect. I started off with putting the ripple grid below the fracture terrain. I then set collisions for the metaball against the fracture terrain. But it ended up not working. I decided to ask Eric on how to proceed from there. Eric told me to try to do it using the simplest method. Which is velocity.

He showed me an example,



The way of how the velocity is created is based on point position distance. Using the same object, He duplicated it and scale it smaller/bigger. Then a point sop is used to calculate the difference.

This is how the expression looks like:



What this expression does is it takes the bigger object with a higher point position and minus the smaller object with the smaller point position. That outputs a direction vector which then can be used as the velocity.

To adjust the velocity I could just scale the smaller object.

It is all done by scaling.




BEFORE:




AFTER:



Note: The orange lines is the velocity vector.

After that, I applied it to my scene.

I duplicated the metaball system which drives my wave.




I adjusted the size also, and I did a point sop. Exactly the same as the help file Eric provided me with.



I then did an attributeTransfer to transfer the velocity attributes to the terrain.



It works as my ripple works. I then brought it into dops. However with this setup, I couldn't break the pieces up. I do not know why, but I think I will call it a day now. So I will settle that on Monday. However I posted my problem on odforce, hopefully someone could give me a solution by Monday.

Day 11

We came into office late, around 9.30am. I sat down and continued working on my shader. Just messing around here and there. Until now still trying to figure out how writing shaders actually work in houdini. I didn't have any experience in shader writing at all.

My updated rock look:





Around 11am, John came and gave a basic VOPSOP class. Just what I needed! He made his class real basic and I learnt a lot from him. The next step I hope to be able to bring it further. His class ended around 1pm.


Charles was scheduled to give his class on materials later. After lunch he started his class at around 2pm. He gave a basic breakdown of the mantra surface shader. All the tabs and what they do. He also told us how to bring in the local parameters of the shader onto the geometry level.

Below is the render on what he taught us:



After that he showed us how to build our own simple shader with noise displacement.







There seems to be some problem with my file, but I got the overall idea on how it worked though.

After that, Mr Steven came by in the evening and looked through our previs and reference pictures.

He told me that my previs was okay just that I got to do some blending and work on the transition for the shot which the camera looks down to the shot that shows the energy sphere moving. He also gave me suggestions on how to do it.

1- Add growing spheres with alpha at the edge of the ripple and when the camera looks down, have some of them cover the camera for the transition. And for the energy ball shot transition, I could have some of the spheres move down instead.

While he was telling me all that, I got some ideas of my own. Once they are conceptualize, I will post them.

I showed him my rock shader and he said it look okay. And it seems like now, my rock has to gear more towards the meteor feel. He showed me a thread on odforce regarding rocks:

http://forums.odforce.net/index.php?/topic/9532-rock-hard/page__hl__rock__fromsearch__1

He asked me to check it out.

I also asked him regarding the displacement of the pre-fractured geometry pieces from the ripple.

He told me that I could set up a rbd collision system. I could overlay the ripple simulation below of the pre-fractured pieces. I could then use the ripple as a collision object that drives the pieces apart.

When he said that, the idea sounded quite complex, but I would give it a shot next week. I will work on my previs tomorrow.

Will be going out for dinner with him and his wife later!

Will blog tomorrow!

Day 10

Today was a long day I would say. We came in at 9am, sat down and started work. I worked on the files Mr Douglas wanted. I finished at around 11am and I realised that was a problem.

The problem is that the whole terrain flips over when I play it before it breaks. I do not even know if the secondary fracture even works now though.

BEFORE:



AFTER:






I asked Mr Douglas if he would mind helping me look through it. Sorry Mr Douglas.

Below is my finally completed documentation:




I moved on after that. I looked at Macha's ripple file and decided to implement that idea into my previs to make it more complete.

The biggest problem I have in my previs is scale wise. I am totally clueless about how big is my scene suppose to big but for the pre-vis now is too big until the camera can't see it. That is why there is that flickering thing.

Below is my previs with the added ripple effect. I will update the video later on.





After doing that I when on to do the last optional shot( If I had time ) I just did a simple one and this is how it looks:




After that I flipbooked out all the necessary frames and I am so called "DONE". Oh ya, before I forget, I re-did my storyboard just in case Mr Steven wants to see it tomorrow.

I went looking for more references for my shots. Below are all my references:


















After that I went into trying to build my own shader. I looked through the help files available on the CMS and also on odforce. I plugged some nodes from the files I looked through and came up with a shader network for the first time in my life.

Below is how it looks:





That is what I have done for the entire day today. Totally not productive I would say.
Hopefully I will be when I actually get to start working on my shot.

Screwed up!




Previs

Day 9

Today, we came to office at around 9am. After settling down, I surfed the internet for a little while. After that, there was a demo lecture by Jeff Wagner using Vidyo. The demos that he did was very good, but a little too fast for me if you ask me. I tried following but I couldn't really catch up. I ended up just sitting there listening to what he is saying.

The demo ended at around 11plus. Oh gosh, I remembered I had to rebuild the secondary fracture file for Mr Douglas and also document it. I started doing it. After doing it for awhile, say, 12plus, We went for lunch.

We came back at around 1. Eric was having his dry run on his attribute class which will happen this evening. He was in the midst of it and we just came in quietly and sat down. He was going through, local, global variables, painting attributes, attributes transfers and stuffs like that.

His dry run lesson ended at around 4pm. We messed around with his files for a little while before Corinne came and gave us a lecture on procedural modeling. At first she showed us a organic model which one of the other intern did. It was amazing. Just by looking at the number of nodes scares people. I guess I still have a fear of modeling, especially procedural modeling.

She started the class by doing a in-class exercise with us. It was to model a bridge procedurally. We started off with a curve. We stretched the curve a little and made the parts of the terrain which the curve was touching flat. That was done using a vopsop. A circle was used and copied onto the curve itself to create the arcs. The circles are trimed away from the curve leaving its shape outline behind. Then some volume is given to it at the end. She told us as our little assignment, try to make the bridge more procedural, and also try to improve it. I wonder will Ari take a look at it when he gets back. Anyways, tomorrow is VOPSOP class. Hopefully will learn something new.

After her class ended, We stayed behind till around 6pm. I continued finishing the file Mr Douglas wanted. But I realised that when I did it, I encountered some stupid orient problem which screws up the entire thing. Gosh. Will look through it tomorrow.

Sorry, no pictures though, not sure if they any can be posted.

Day 8

Today is week 2 of the SESI attachment program. We came to the office, and started working on our project previs so that it could be shown sometime soon. I didn't took long to finish my work though. I spend the rest of the time looking through odforce for files and also sidefx.com. I found many ripple files but none of them seems to apply to me. But anyway, some screenshots,




This is using metaballs to create the ripple effect and it is driven by a magnet sop.





This is created by sculpting the initial shape for the ripple and using the ripple object and ripple solver to create the ripple effect in dops.

I did a simple pre-visualisation for my project and below is how it looks:

Some screenshots:








In simpler terms, my idea is a rock hits the ground and causes a wave/ripple like shattering effect( similar to Thor ).




And my reference for the terrain:




Ari mentioned on Friday that he will be coming in tomorrow. Hopefully I could finish the pre-vis compilation tonight and show it to him. Oh gosh, I need to clean up my photos from Downtown also, in case he wants to see.