1 February 2023
Week 4 - Harbor Picture Company x SCAD
After our meeting with our Harbor mentors during week 4, I am coming to realize how far we have come since the beginning of the quarter... and how much we still need to work on! Although we would like to put our hands on everything, it's important to take a step back and prioritize which things need the most focus.
Team Beluga met after the meeting and assigned each of ourselves a shot which would highlight our skills. We also listed our priorities for this week so that they would have the most noticeable change by week 5! For myself, I need to focus on look-dev and some camera move adjustments suggested by our mentors. Now that we finally have our perfume bottle model, I need to make the glass look as realistic as possible.
Week 4 Goals
- Look Development: Glass and Perfume Shaders!
- Lengthen shot 4
- Slow Camera move for shot 2 (not static)
Redshift Trace Depth Settings
During our recent meeting, I was directed to the dark black refraction of the perfume bottle glass in our previs render. While I want to check my IOR and glass shader settings, first I am going to go into the render settings and adjust the trace depth settings to compare before and after.
First, I changed the default "Combined" value from 6 to 20. This way, I could adjust more parameters and see a change. I may need to up it more in the future. You can already notice a change in the bottom of the perfume bottles between the image above and below.
Next, I started upping the refraction little by little until I noticed there was no more significant improvement. I found 10 to be a good value to end.
After adjusting the Refraction, I planned to adjust the reflection in increments until it was high enough to see improvement without upping render time significantly. However, it seemed only going up to 5 made any improvement.
IOR - Index of Refraction
Going back into the RS material, I wanted to see the default IOR and what I could change it to in order to get the most similar glass IOR of the perfume bottle. The default, which is seen in all the images above, is 1.5. After some research, I learned that expensive brand perfume bottles are made from crystal, leaded glass or soda-lime glass. After further research, I found crystal has an IOR of 2.0, so lets visualize that on our bottle!
To visually see the glass easier, I removed the inner orange box to focus only on the glass bottle with an IOR or 1.5, the average IOR of glass, vs 2.0 for crystal.
Comparing these two, I think the crystal glass looks more accurate and removes the black refraction we notice with the 1.5 IOR. I will need to consult with my peers and Professors for more feedback.
2 February 2023
Continuing to work on glass, I first replaced the bottle model with the most updated version by Dee. This new, updated version has thinner glass walls and will give more accurate refractions within the glass. I will also continue working on the glass with only one bottle at a time, since the images above can have odd refractions with bottle after bottle.
Let's compare the two bottle versions to see how the refractions of the glass changes with an IOR of 1.5.
In Redshift Houdini, there is an RS Material and an Rs Standard Material. While they are similar and can both have out color that can be plugged into the redshift_material node, they have different control.
The Rs Material Node has presets for materials you can choose and alter as needed which can be seen as convenient for beginner shaders. An important control that the Rs material node has (which the Rs Standard Material node doesn't) is the choice to change the BRDF between 3 different options. These options include: Beckmann (Cook Torrence), GGX, and Ashikhman-Shirley. First, let's research the difference between Beckmann and GGX!
A great resource I found was https://tryingtobeananimator.wordpress.com/2018/11/25/technical-ggx-vs-beckham-why-and-whats-the-difference/ which gives visual comparisons of the difference between Beckmann and GGX. When it comes down to it, they explain GGX as a more accurate version of BRDF, making it's renders more "realistic". BRDF, or Bidirectional reflectence distribution function, is described as the "relationship the light and view vectors and describes the light response at the shading point based on those two variables." -https://tryingtobeananimator.wordpress.com. Although I have found many sources that tell me which setting to use for which, I found this source to be most valuable. Regarding the Ashikhman-Shirley, I have found it looks very identical to Beckmann, but might up the render-time.
Now, I can understand the setting in the shader and analyze visually which gives the best appearance.
Rs Standard Material
After going into the Rs material node and comparing the different BRDF's, I found that the glass doesn't change visually, and the only small noticeable change is in the drop-off of the light on the ground. Even then, the difference is very slight.
I conclude that the Rs Standard Material is the direction to go after comparing the two images above.
After tweaking the glass of the bottle, I wanted to start visualizing the yellow-orange perfume inside the bottle once more. One of our crucial notes from last session was that our current shader of the perfume was too deep and resembled whiskey! After a member of team Beluga, Dee Divakaran, bought a small sample bottle of the Cuir Beluga perfume, its clear how different the perfume looks in real life compared to our current shader.
With the help of Dee Divakaran, we worked on trying to adjust the shader to get the correct color of the bottle in our render. Here is one of the first iterations compared to how it looked last week.
This Week - First Iteration
3 February 2023
Something I needed to problem solve was how to remove the black refractions that were noticed in the previs and above. My first solution was to put a large sphere around the scene with a white shader to remove and black space that the bottle was refracting, and thankfully this resolved the issue.
After some more tweaking and referencing our real-life perfume, here is the new update to my look-dev rig. This is just a still to show how the color of the perfume is being tweaked to look less deep and saturated like a whiskey commercial. I also went in and adjusted the dark black values which were too dark before.
Upon rendering this version, I was asking myself what I did wrong to accidentally remove the caustic light we saw in the photos above. After investigating the reason behind this, I soon found out it's because I need the inner layer of the glass inside the bottle with the same texture as the outer layer of the glass. In the render above, I turned it off thinking I didn't need it.
To help with color match and understanding the glass IOR refractions, I constantly am holding the smaller perfume sample next to me as I work! *The camera distorted the color*
From this stage on, some important factors I need to consider with the bottle is the thickness of the base in my reference, how beveled the base is in real life compared to our model / renders, and what I can do to get an inner caustic light hit those internal bevels inside the bottle.
Here is a comparison of before and after going into the maya file and editing the scale of the inner bottle and bevel!
Although our Motion Media designer Dee Divakaran is going to make a texture for the logo, I used a quick png to visualize what it would look like with the logo on!
4 February 2023
After meeting with Dee Divakaran to discuss the new changes to our bottle, she gave me a new version of the bottle .obj where the inside base curved in more to create a better bevel. Here is a comparison of before and after!
As a small break from my other tasks, I dove into shot 5 to attempt switching the bottles out for the new version to see how to would appear in the scene! However, the perfume would appear very dark regardless of turning up the light intensity.
To solve this issue, I turned off all light in the scene and placed an rs environment light to see how the black refraction would respond. As you can see below, a low intensity environment light removed the refraction and brings back that orange-yellow color!
Here is a test render of replacing the bottle in shot 1 and tweaking some of the shaders in the environment! I took the render into nuke to also test the zDefocus.
After receiving Dee's first version of a displacement map for the bee on the bottle, Dee Divakaran and I were eager to plug it into our shots. However, we both struggled with plugging in the displacement map into the rs material builder. We first put down the texture, added an rs displacement node, and plugged the "out" into the "displacement" of the Redshift material node.
We both struggled to find why our displacement was not appearing. We ensured that we:
- applied uv's to the outer shell of the bottle
- the bee of the displacement map was in the correct spot
- went into the "object parameters" of the bottle and checked ON "tesselation" and "displacement"
First, to visualize that the bee map was accurately placed, I plugged the map into base color.
Since this appeared accurate, I then inverted the image, turned displacement back on, and switched our image from a tif to a png. I also attempted adjusting the displacement scale since it looked too large. Here was our result:
It appears like the bottle is displacing but the bee is staying the same, so my first thought was to use an invert node. However, inverting does not solve the problem. It removes the displacement entirely! We will need to find a way to solve this in the future. For now, here is the displacement set very small at .02
5 February 2023
Continuing where we left off, I wanted to problem solve why I was seeing this line in the bottle.
First, I disconnected the displacement to see if that's where it came from (since this only became an issue after I started working on the displacement). Unfortunately, the line was still appearing.
Next, I went into the object parameters of the bottle and turned off "tessellation". this removed the line I was noticing!
After talking to team Beluga member Galina Bovykina, she directed me to blur the displacement map of the bee to get a smoother fall off then the straight lines we were noticing. Here was the result of connecting a blurred displacement map!
Shot 5 Lighting Update
Once I opened shot 5 to update our new bottle, I needed to go back into the lighting to remove the black refractions I was noticing. I had to restart all the lighting and placement, but the first variation was exciting to see!
The image above felt very flat and reminded me of a look-dev rig, so I seeked a different direction in what we could do for the shot. Here is a reference that would be a nice inspiration for this shot's lighting / background!
Using this as inspiration, I first deleted the backdrop to see what the bottle looked like against a dark void.
However, I would want to see the reflection of light on the ground, so I brought back the backdrop and turned the shader's weight to a very dark grey!
Look Development Rig
Here is a rendered turn table of our Cuir Beluga Perfume bottle for week 4!