Cheetah3D 7.3 Beta 2

Thanks!

The render is from a series I made while experimenting with different ground textures and apparently I didn't save that iteration (simple fractal node plus power function as bump texture, but the parameters are lost now).
So here's a file without texture:
 

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Glass Ring


image.jpg

PBR wood material with specular=0 for faster rendering
 
Shadow And Light


glassrings.jpg
without texture
 

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Right after the v7 beta arrived, I experimented with severe distortion on simple shapes, just to get the hang of it. Caustics were where I was hoping to get, but the kinks weren't worked out yet. Now, however...

I used misoversaturated's cubes file as a base, and am finally starting to understand how it all flows together. Lots of directions to go with this.

Thanks, Martin! This is fun!
 

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Last renders of the caustic cube series


image.jpg

image2.jpg

Some observations:
The Falcon renderer has several default settings relevant for rendering refractive caustics:
Clamp sample = 10
Adaptive sampling = on
Ray depth = 10 ( 3,2,10,8 )
Caustic filter = 0.1

The ray depth here is often too low and should be set higher, especially glossy bounces should equal specular bounces in order to catch internal reflections.

The other settings normally grant clean and speedy renders with adaptive sampling but are coming with restraints:
The caustic filter is blurring caustic patterns. Lowering the value to get sharper caustics heavily increases noise and render times.
Clamping samples is another restriction introducing bias by discarding light (violating energy preservation).
For my taste the default value of 10 is too low regarding light balance (especially in combination with filmic tone mapping).
Increasing the value again causes more noise and longer rendering.

So the default values together are optimized for manageable rendering at the expense of aesthetic quality.
That's ok for scenes with small, not dominant refractive objects.
When the values are changed the noise detection from adaptive sampling starts to struggle.
I often resort to rerendering parts of the imige with a camera mask and denoising in Photoshop.

One more hint:
Clamp settings in the light properties also compromise caustics so I tend to disable them (in HDRI object set value to zero).
 

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Added skeletal animation support to the GLTF/GLB exporter today. Now I'm pretty much done with it.:smile:
 

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Some observations:

Thank you so much for your insights. They are going a long way towards helping me through my learning curve.

I haven't decided how I want to sculpt the base for this yet, but the render is almost the lighting and texture I want. I may need a higher resolution on the clock face texture, although the softening may caused be seeing it through the glass lens.
 

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command line gltf2usd converter

For those interested.

A gltf2usd converter was dropped on github 5 days ago. The tool is a command-line Python script which converts glTF 2.0 models to USD, with the goal being simple pipeline conversion from glTF to usdz using Pixar's usdzip or Apple's usdz_converter.

I have not had a chance yet to test this myself personally from Cheetah by using the gltf export. But I know someone who has successfully exported a bone animation from blender -> gltf . Then used the gltf2usd command line tool to create a usd. From there you can use the xcode command line tool usdz_converter to create a working usdz bone animation. Currently the bone animation is working on the Mac file system, but not ios12 beta 8 via the safari browser (maybe bug).

Anyway, the good news up until now the only way to create a usdz file with bone animation would have been using the full version of maya+usd plugin.

Whilst not the most straight forward method having to use two different command line tools, its still possible to fully access Apples new format via Cheetah 3D.
 
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After my initial post I realised that the gltf2usd converter only supports the glTF 2.0 specification. As C3D only supports glTF version 1.0 specification... its not possible as yet to build a USDZ bone animation via C3D glTF exporter + gltf2usd tool + usdz_converter xcode tool.

BTW, Apple just released a pixar USD standalone library to streamline the whole process of building USD/USDZ files on a MAC. Its available to anyone with an Apple Developers account. download link at the bottom of page.

Martin any plans for glTF 2.0 support in C3D to make this possible?
 
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I'm pretty sure Martin did use the glTF 2.0 specifications:

https://www.cheetah3d.com/forum/showpost.php?p=106750&postcount=14

Pegot,

I was NOT familar with glTF at all up until yesterday. Since then I have been trying to understand the variations.

The glTF2USD command tool rejected the C3D created glTF for Alien_walk. I originally thought it was because it may be glTF 1.0.

However, after opening the Alien_walk file and finding embedded base64 data....it may be because the glTF2USD tool doesn't support glTF files with base64 data embedded.

I looked at the preferences for glTF files in C3D and it doesn't seem to have an option for not having base64 data.

Code:
This tool currently only works on glTF 2.0 files with external textures, based on the core glTF 2.0 specification (no extensions).

Supported Features
glTF nodes are mapped to USD Xform
glTF PbrMetallicRoughnessMaterial is mapped to USDPreviewSurface
glTF Skeletal animation is mapped to UsdSkel
glTF node animations are supported
Currently supports .gltf conversion to .usd, .usda and .usdc
Currently not implemented:
.glb files
[COLOR="Red"]glTF files with base64 data[/COLOR]
PbrSpecularGlossiness or other glTF extensions
Primitive modes (other than triangles)

Anyway, it would be nice to know if it is glTF 2 for certain & whether or not the file can have option to have base 64 data or not?

I personally don't no enough about the file format to understand the pros and cons for such an option.
 
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I don't understand anything about file formats and their coding but Martin said above:
I've already started work on animation. Object animations are already working but skinning is still missing. But it will follow soon.
Added skeletal animation support to the GLTF/GLB exporter today. Now I'm pretty much done with it.:smile:

From this I understand that the bone animation in the alien walk file will not work in a Cheetah glTF file exported with the current beta2 but will do so in the upcoming beta3.
 
I don't understand anything about file formats and their coding but Martin said above:



From this I understand that the bone animation in the alien walk file will not work in a Cheetah glTF file exported with the current beta2 but will do so in the upcoming beta3.

Yes, corrected Beta 2 has the animation option on the exporter dialogue box, but the animation itself isn't in the beta2 release.

Unfortunately, I've had no luck getting any bone animations from C3D -> usdz successfully. I tried using fbx exports... then using the FBX2GLTF command tool. I've also tried using the COLLADA2GTLF command tool and it also doesn't generate the correct GTLF. I've had slightly better results with Blender, but not much better. I'm looking forward to the C3D release because it may give me another avenue to try.
 
Viewport: Hoover hints broken?

Are the Hoover hints broken lately or just missing, Martin?

Cheers
Frank
 

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In some former version there was a bug regarding blurred reflections (roughness) rendering black which has been corrected.
But it seems in a fringe case the problem still persists, that is in Cheetah renderer with no radiosity or ambient occlusion but lighting by HDRI only.
When roughness / blurred reflections are set =/=0, indirect reflections turn all black.

image.jpg
 

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Transform-tool in Gadget-mode won´t snap

Transform-tool in Gadget-mode won´t snap to point at yxz=0:

Cheers
Frank
 

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