Hello patrons,
In this video we will finish this mini series about Solaris and Katana interoperability.
I'll be covering the topics that I didn't have time to cover in the first video, including.
- Manual set dressing from Solaris to Katana.
- Hero instancing from Solaris to Katana.
- background instancing and custom attributes from Solaris to Katana.
- Dummy crowds from Solaris to Katana.
- Everything using USD of course.
There are many more things that could be covered when it comes to Solaris and Katana interoperability, I'm pretty sure that I'll be covering some of them in future USD videos.
All the info on my Patreon.
crowd
Dummy crowds in Houdini Solaris /
Quick video showing how to use one of my oldest tricks to create “dummy crowds“, but this time in Solaris, which makes this even easier and faster than using SOPs or MOPs.
I’ve used a flavour of this dummy crowds technique in many shots for a bunch of movies. It is very limited in so many ways, but when it works it works. You can populate your environments in minutes!
Please consider subscribing to my Patreon so I can keep making professional VFX training. Thanks. www.patreon.com/elephantvfx
Clarisse scatterers, part 01 /
Hello patrons,
I just posted the first part of Clarisse scatterers, in this video I'll walk you through some of the point clouds and scatterers available in Clarisse. We will do three production exercises, very simple but hopefully you will understand the workflow to use these tools to create more complicated shots.
In the first exercise we'll be using the point array to create a simple but effective crowd of soldiers. Then we will use the point cloud particle system to generate the effect that you can see in the video attached to this post. A very common effect these days.
And finally we will use the point uv sampler to generate huge environments like forests or cities.
We will continue with more exercises in the second and last part of these scatterers series in Clarisse.
Check it out on my Patreon feed.
Thanks,
Xuan.
Houdini as scene assembler part 05. User attributes /
Sometimes, specially during the layout/set dressing stage artists have to decide certain rules or patterns to compose a shot. For example let’s say a football stadium. Imagine that the first row of seats is blue, the next row is red and the third row is green.
There are so many ways of doing this, but let’s say that we have thousands of seats and we know the colors that they should have. Then it is easy to make rules and patterns to allow total flexibility later on when texturing and look-deving.
In this example I’m using my favourite tool to explain 3D stuff, Lego figurines. I have 4 rows of Lego heads and I want each of those to have a different Lego face. But at the same time I want to use the same shader for all of them. I just want to have different textures. By doing this I will end up with a very simple and tidy setup, and iteration won’t be a pain.
Doing this in Maya is quite straightforward and I explained the process some time ago in this blog. What I want to illustrate now is another common situation that we face in production. Layout artists and set dresser usually do their work in Maya and then pass it on to look-dev artists and lighting td’s that usually use scene assemblers like Katana, Clarisse, Houdini, or Gaffer.
In this example I want to show you how to handle user attributes from Maya in Houdini to create texture and shader variations.
In Maya select all the shapes and add a custom attribute.
Call it “variation”
Data type integer
Default value 0
Add a different value to each Lego head. Add as many values as texture variations you need to have
Export all the Lego heads as alembic, remember to add the attributes that you want to export to houdini
Import the alembic file in Houdini
Connect all the texture variations to a switch node
This can be done also with shaders following exactly the same workflow
Connect an user data int node to the index input of the switch node and type the name of your attribute
Finally the render comes out as expected without any further tweaks. Just one shader that automatically picks up different textures based on the layout artist criteria
Clarisse shading layers: Crowd in 5 minutes /
One feature that I really like in Clarisse are the shading layers. With them you can drive shaders based on naming convention or location of assets in the scene. With this method you can assign shaders to a very complex scene structure in no time. In this particular case I'll be showing you how to shade an entire army and create shading/texturing variations in just a few minutes.
I'll be using an alembic cache simulation exported from Maya using Golaem. Usually you will get thousand of objects with different naming convention, which makes the shading assignment task a bit laborious. With shading layer rules in Clarisse we can speed up a lot this tedious process
- Import an alembic cache with the crowd simulation through file -> import -> scene
- In this scene I have 1518 different objects.
- I'm going to create an IBL rig with one of my HDRIs to get some decent lighting in the scene.
- I created a new context called geometry where I placed the army and also created a ground plane.
- I also created another context called shaders where I'm going to place all my shaders for the soldiers.
- In the shaders context I created a new material called dummy, just a lambertian grey shader.
- We are going to be using shading layers, to apply shaders globally based on context and naming convention. I created a shading layers called army (new -> shading layer).
- With the pass (image) selected, select the 3D layer and apply the shading layer.
- Using the shading layer editor, add a new rule to apply the dummy shader to everything in the scene.
- I'm going to add a rule for everything called heavyArmor.
- Then just configure the shader for the heavyArmour with metal properties and it's correspondent textures.
- Create a new rule for the helmets and apply the shader that contains the proper textures for the helmets.
- I keep adding rules and shaders for different parts of the sodliers.
- If I want to create random variation, I can create shading layers for specific names of parts or even easier and faster, I can put a few items in a new context and create a new shading rule for them. For the bodies I want to use caucasian and black skin soldiers. I grabbed a few bodies and place them inside a new context called black. Then create a new shading rules where I apply a shader with different skin textures to all the bodies in that context.
- I repeated the same process for the shields and other elements.
- At the end of the process I can have a very populated army with a lot of random texture variations in just a few minutes.
- This is how my shading layers look like at the end of the process.