Shader Portfolio – Unbiased Vs. Biased Rendering

Biased Vs Unbiased Rendering

Biased: Gives the user complete control over how the renderer interprets the scene. This means calculations for Spectacularity, Global illumination, Final gather, Shadows etc. have to be manually entered by the user and are a result of how the user feels the lighting interacts with the objects within the scene. This doesn’t always mean that the users interpretation of how the light interacts is physically correct, this can take a lot of finessing and if not done in the correct order, can quickly look “wrong”. Renderers such as Mental Ray, Vray and Renderman are known as biased renderers.

Unbiased: Is the opposite of a Biased, meaning that the renderer is in control of calculations. By doing it this way the renderer can create physically correct renders with minimal work for the user, who is in control of noise clean up and the amount of bounces in Diffuse and Refraction. This offers more control and less room for error with calculations. Renderers such as Arnold are unbiased and are increasing in use within the film industry due to their speed and render quality.

The pro’s and con’s of each render type can be broken down;

Biased
Pro’s; More control, faster render speeds, ability to choose quality of work also the user can predict possible render times, render times can go from seconds to minutes depending on global illumination and final gather photons as well as light quality and the amount of objects within the scene, better for use with hard caustics.
Con’s; Less ability to achieve realism and this isn’t dependent on how much quality the render has, but how the render handles information. However it can still produce quality renders.

Unbiased
Pro’s; Physically correct, realistic, less work for the user meaning some adjustments regarding camera and scene clean up and real time updates using the IPR render option, better at soft caustics.
Con’s; The render is never actually done, render times can be unpredictable and the overall quality cannot be chosen.

Reference: http://basic3dtraining.com/whats-the-difference-between-biased-and-unbiased-render-engine/

 

A Late Return

So 2015… My final year of TAFE…

At the end of this year I will hopefully be walking away with a Bachelors degree in 3D and Animation… Looking at finding work overseas as well.

So naturally now all the TAFE work posts are going to start. For my elective this year I have chosen to do Lighting/ Rendering and Compositing. So there will be a lot of posts relating to those things.

I also have to develop my showreel this year and plan to document the process as I go. So hopefully there will be some interesting things regarding that with pipeline and concept.

Wish me luck and hopefully enjoy :)

d403dc0260_2_68535980_f5db86-post

Environment Pre Viz

Image converted using ifftoany
This is just an upload of something old, for TAFE purposes :)

Satellite Soda Daily Draw February 2015 – Update

So it is day 5 of the daily draw for 2015, here are two of the drawings I have done.

Just a little run down on what has been going on;

Day one: I did a quick wolf sketch in an hour to make sure I kept on task and drew something for the day. He is done on Bond paper with a fine liner pencil.

dailyDrawing_wolfFixed_001

Day 02: Due to personal reasons, day 02 had to be skipped.

Day 03: With day 02 being skipped I wanted to try and work on some digital painting as I don’t feel 100% drawing like this, so I took this chance to try and push that. Time constraints meant I couldn’t finish the work so I uploaded a W.I.P to show I had worked on something. I feel this way of doing things with a little bit of pressure that isn’t stressful is somewhat enjoyable. 

 


dailyDrawing_legsWIP_003
Day 04: I finished off the painting from the day before. It got to a point where I had to say enough was enough but I feel somethings could still be better but at the same time I got to work on values and colour. I think that composition, movement and anatomy could be improved, but this is why I am doing this as a way to get myself to fix these things.

dailyDrawing_legs_004

 

If you are interested I have a facebook and an instagram you can follow along with :)

https://www.facebook.com/twentythreebydesign

@twentythreebydesign

Satellite Soda – Daily Draw 2015

So I just signed up to this! I am hoping to gain some good habits and some much needed drawing time whilst stop making excuses.

Wish me luck :3

http://satellitesoda.com/post/view/10/daily-draw-2015

dd2015

Dynamics VFX: Final UFO Tractor Beam

For the final part of this assessment, we were given “client feedback” to make our adjustments to the tractor beam simulation before final submission to try and replicate what might happen in industry. Below is the feedback I received for my previous blog post;

“CLIENT FEEDBACK:
The outer cone of the tractor beam has a nice look to it. I like how it has the diagonal shafts coming from the top, it gives some variance to its makeup.
The tractor beam is turning on too slowly though. It needs to happen much faster so that there is time to lift the mannequin into the UFO. Think no more than 15 frames. 
We need to get some more detail into the simulation. I’d like to see thin rings run along the surface of the outer cone. These would move from the UFO down to the ground. As they run along the outer cone they would leave a faint trail of particles that would waft away from the outer cone and dissipate into the air. When the rings hit the ground they would dissipate and fade off.
I also want to see more detail in the current outer cone that you have. This will probably mean you’ll need to make the particles smaller and have more of them.
The colour is close, but it has too much green in it. Try to make it more of an electric blue.
Lose the grass type things that come up from the ground. Also, make sure the tractor beam is timed to the opening and closing or the UFO hatch doors. At present that is not happening.”

So I approached this by increasing the over samples of the particles to 3, to make the main part of the cone seem more like a veil than like individual particles. By doing so as well as trying to increase the time of the tractor beam contacting the earth, I lost the cross over effect of the particles. I do rather like the electric blue colour more than the aqua colour I had previously.

I had a bit of trouble trying to get the little rings to look how I wanted them to, I tried several different fields, emitter types and also goaling to an object. In the end I emitted particles from the initial rings I created and turned the visibility off, because I found if I had used any form of keys in the visibility attribute I had issues with the particles turning on and off again. So these initial rings became my emitters for the visible rings. After trying several fields, Newton, Gravity, Turbulence, Air, and Drag, I settled on using a Radial field. This still didn’t quite give me what I was after but I needed to keep moving forward in order to finish the simulation. I would rather that the particles actually moved away from the centre of the rings in a horizontal motion and slowly glittering into nothing.

I removed the particles floating up from the ground, I can see how they weren’t the desired effect. I only kept the point particles falling from the UFO, these I changed to a golden colour to add a little subtle contrast to the simulation and added a noise texture to the opacity ramp to make the particles sparkle on their way down.

After struggling a lot with the rag doll simulation, I finally got the simulation to work however I had further issues importing my file into the VFX file, so to get around this problem I referenced the original reference and made the hinge constraints and parenting constraints within the VFX file. I know this might not be the way it was meant to work, due to the assessment reflecting industry, however I wasn’t sure of the issues and needed a quick solution, so I improvised.

Below is a playblast of my final simulation, I feel the ring particles could be a little too fast but this can be changed later if need be.

Dynamics VFX: Rag Doll Tutorial; Hinge Constraints

The Dynamic sub menu in Maya is not just about creating particles. Within this menu set, you can create basic skeletons for characters using hinge constraints that will be used with fields to generate basic movements without having to set keys on the timeline. These dynamic simulations can, if need be, be baked out and keys added to the time line once you are happy with the over all result of the simulation.

In this tutorial, we will be looking at how to construct a hinge constraint skeleton for the mannequin provided in the UFO scene file for the tractor beam assessment. The aim is to get the mannequin to start off in a standing position, then once the tractor beam has done what it needs to in order to lift the mannequin up, we will use dynamics to lift him into the hatch of the UFO.

To start we need to have a model, in this case our wooden man, free from constraints and that the geometry is separate. Here is the model I will be using for my simulation.

mannequin

Because our geometry is separated, we will need to attach it to the rest of the mannequin to avoid geometry being left behind when we go to add fields to the finished mannequin. For example;

woodenMan_gravityField

I found that the best way to attach the ball joint geometry to the rest of the models geometry is to parent constraint selecting the “r_upperArm”  and then the “r_shoulder” going to the animation sub menu > constraints > parent option box, reset the settings and making sure maintain offset is turned on.

parentConstraint_options

Hit apply and repeat this for the rest of the ball joints. Your mannequin and out liner should look like this once you have completed this step.

parentConstraint
parentConstraint_geo
You can also do a straight parent for this step, however I had some trouble with getting this to work for me.

Now that the mannequin is parent constrained, we can start setting up our hinge constraints. Selecting the head of the mannequin then the chest, go to the Dynamic Sub Menu > Soft/Rigid Bodies > Hinge Constraints Option Box. Before we do anything else make sure the settings are reset within the tool, File > Reset Settings; make sure the drop down menu stating which type of constraint it is has hinge selected.

hingeConstraint_optionBox

Above is an example of the options I used when applying the hinge constraint to the left ankle. Besides from little adjustments to the translation and rotation of the constraints, I found this way to work. Continue to do this to the rest of the mannequin by following the flow of joints; for example select the chest and then the right upper arm and constrain then move and rotate the constraint into position, replicating how a joint should bend, now the right upper arm then the right lower arm and constrain then move and rotate the constraint into position, the right lower arm and the right hand then constrain then move and rotate the constraint into position.

You will end up with a skeletal structure looking like so;

hingeConstraint_skeleton

To test that everything is working, select for example, the hand and apply a gravity field. Depending on which direction you wish for your mannequin to move, change the settings in the gravity field to achieve this. For me I want my mannequin to float upwards so I will change the second attribute in the direction fields to a positive number and bump the magnitude up to a number that will actually cause an effect, for me I chose 100. Make sure you have enough frames on your timeline to create a decent simulation to accurately test that it works.

gravityField
If all goes well, then your final simulation should end up looking like this;

finishedMannequin

 

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