Hello all,
This thread is in response to the question raised in MMounteer's Windmill Model thread < https://www.cheetah3d.com/forum/index.php?threads/14012/ > regarding "painterly" HDRI backgrounds.
Rather than hijack that thread which is focused on their beautiful image with my image, my observations, and any further discussion of using non-photographic HDRI lighting/background, here we are…
This scene/rendering was done rather quickly (using pieces I had previously made for my quiver) to illustrate my answer to the "painterly" question in a timely fashion.
The ocean and all land masses are extremely high-poly models. For what it is worth, only a small part of that overall scene is visible in this image and so the closeup pieces of land could use more polys to smooth out the curves. But that is not important in this context.
The windmill (which is distinctively from another continent and also a high-poly model) was included to provide some, hopefully amusing, continuity to the referenced thread.
On to the point of this post…
The sky is a spherical HDRI I painted in Photoshop. It was used as the source image for a HDRI light with Background: checked.
I would imagine that other pieces of software, perhaps including Affinity Photo, allow for the painting/editing of 32bit HDR images.
In the past I painted HDR images for backgrounds that included objects and land masses. I've moved along from doing things that way for a variety of reasons. One primary reason is the inflexibility in the fixed apparent lighting of a painted background. For my purposes, the tradeoff of enduring slow C3D response times when dealing with 50 some million polygons and triangles is not having to repaint the land on the background whenever I want to change the lighting or when moving the camera around for a different view of things.
To the topic of low or high resolution HDRI for the HDRI Light in C3D…
While I have been using C3D to create models (and test rendering while building a model) for many years, it is only in the past year that I have really started using C3D for serious final rendering. For many years longer than I have been modeling with C3D, I rendered with Electric Image. With new Macs requiring new versions of MacOS, my EI rendering days were drawing to a close with no 64 bit clean EI being released. It was moving on from painting backgrounds with landmasses to modeling the land masses and oceans a year ago that finally forced me to stop rendering in EI. Even though there are many things left behind in that change, the number of polygons C3D can handle leaves EI crashing from lack of memory on my old Mac Pro Cylinder with only 64GB of RAM.
EI provides for the use of synchronized images of different resolutions and bit depths to be used where appropriate. E.g. Low resolution 32 bit HDRI for lighting, high resolution 32 bit HDRI for reflections/refractions, and high resolution 8 bit for backgrounds. All matching spherical ratios.
When I first started using C3D for the final rendering, I continued to use high resolution 32 bit HDR image as the source image in the HDRI Light. I have now switched to using relatively low resolution images for the HDRI Light source image/background.
While, from my experience, I don't think there is a huge difference in rendering times, the memory footprint is certainly lower. And since I no longer include any near or mid-field objects in a background image, only sky and clouds, the low resolution 32bit HDR source images look just fine and dandy. The max dimensions output from C3D is 8192 px square. Perhaps if C3D was able to render a far higher resolution output, a higher resolution sky with clouds might make a noticeable difference.
Again, my work does not rely on a background image for anything but light and sky with clouds. Neither does my work lend itself to using a flat projected rectilinear background plate.
So, this will not address everyone's needs, but hopefully it can be helpful in some way.
Cheers,
gsb
This thread is in response to the question raised in MMounteer's Windmill Model thread < https://www.cheetah3d.com/forum/index.php?threads/14012/ > regarding "painterly" HDRI backgrounds.
Rather than hijack that thread which is focused on their beautiful image with my image, my observations, and any further discussion of using non-photographic HDRI lighting/background, here we are…
This scene/rendering was done rather quickly (using pieces I had previously made for my quiver) to illustrate my answer to the "painterly" question in a timely fashion.
The ocean and all land masses are extremely high-poly models. For what it is worth, only a small part of that overall scene is visible in this image and so the closeup pieces of land could use more polys to smooth out the curves. But that is not important in this context.
The windmill (which is distinctively from another continent and also a high-poly model) was included to provide some, hopefully amusing, continuity to the referenced thread.
On to the point of this post…
The sky is a spherical HDRI I painted in Photoshop. It was used as the source image for a HDRI light with Background: checked.
I would imagine that other pieces of software, perhaps including Affinity Photo, allow for the painting/editing of 32bit HDR images.
In the past I painted HDR images for backgrounds that included objects and land masses. I've moved along from doing things that way for a variety of reasons. One primary reason is the inflexibility in the fixed apparent lighting of a painted background. For my purposes, the tradeoff of enduring slow C3D response times when dealing with 50 some million polygons and triangles is not having to repaint the land on the background whenever I want to change the lighting or when moving the camera around for a different view of things.
To the topic of low or high resolution HDRI for the HDRI Light in C3D…
While I have been using C3D to create models (and test rendering while building a model) for many years, it is only in the past year that I have really started using C3D for serious final rendering. For many years longer than I have been modeling with C3D, I rendered with Electric Image. With new Macs requiring new versions of MacOS, my EI rendering days were drawing to a close with no 64 bit clean EI being released. It was moving on from painting backgrounds with landmasses to modeling the land masses and oceans a year ago that finally forced me to stop rendering in EI. Even though there are many things left behind in that change, the number of polygons C3D can handle leaves EI crashing from lack of memory on my old Mac Pro Cylinder with only 64GB of RAM.
EI provides for the use of synchronized images of different resolutions and bit depths to be used where appropriate. E.g. Low resolution 32 bit HDRI for lighting, high resolution 32 bit HDRI for reflections/refractions, and high resolution 8 bit for backgrounds. All matching spherical ratios.
When I first started using C3D for the final rendering, I continued to use high resolution 32 bit HDR image as the source image in the HDRI Light. I have now switched to using relatively low resolution images for the HDRI Light source image/background.
While, from my experience, I don't think there is a huge difference in rendering times, the memory footprint is certainly lower. And since I no longer include any near or mid-field objects in a background image, only sky and clouds, the low resolution 32bit HDR source images look just fine and dandy. The max dimensions output from C3D is 8192 px square. Perhaps if C3D was able to render a far higher resolution output, a higher resolution sky with clouds might make a noticeable difference.
Again, my work does not rely on a background image for anything but light and sky with clouds. Neither does my work lend itself to using a flat projected rectilinear background plate.
So, this will not address everyone's needs, but hopefully it can be helpful in some way.
Cheers,
gsb
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