Vray gpu depth of field

[luisgamino2]

Hi Konstantin, Peter Chauchev and Muhhamed


I'm rendering some spaces and there is another tool that i don't use but i should use since this happens in real life and gives the renders another level of Quality and realism and that is depth of field.

3 things

First is slower to render a scene with depth of field like 20 or 25% that with out it.

Second is that in order to achieve a better bokeh effect i have to increase a Lot the subdivids in the Quality slider, to get a clean bokeh effect.

Third is that how can i know how much defocus is needed to get a Nice shot with depth of field?

Sometimes i have to guess in order to find the Best defocus, and i have to do some test to find the Best number and i Lost time just triying and triying yo achieve the Best defocus number to get a Nice shot.

The option of Focus distance is great but i would like to enhance that part so vray can give us the Best number for the defocus.

Depth of field is very important for architectural rendering.

i loose a Lot of time just guessing what kind of value is the Best... Not to much depth of field but at the same time a Nice effect of that.

That could be really a Nice feature or a Nice upgrade in the camara roll for vray gpu 6 and vray 6.

Thanks
Best regards Luis Gamino

[Muhammed_Hamed]

Hi luisgamino2 I hope you are having a nice weekend,

I'm rendering some spaces and there is another tool that i don't use but i should use since this happens in real life and gives the renders another level of Quality and realism and that is depth of field.

DOF/Bokeh could be very handy indeed, although in reality I have found that most architectural clients don't like this effect and will not allow artists to use it.
On the freelance jobs I did in the past, I barely ever used Depth of Field because of client's feedback. It is something to consider here, usually most people will add a Z depth render element and do their DOF in Photoshop, it will not be the same quality but at least if the client asks you to remove/adjust DOF you will not need to re-render the images.

First is slower to render a scene with depth of field like 20 or 25% that with out it.

This is expected to happen, Depth of field relies on primary rays so it is gonna add to your render time. Similar to Motion Blur, it is a very expensive rendering effect.
So again, it is normal and will happen with any renderer not just V-Ray GPU

Second is that in order to achieve a better bokeh effect i have to increase a Lot the subdivids in the Quality slider, to get a clean bokeh effect.

We are aware of this issue, I have it on the GPU roadmap for some time. I hope we will get to this soon
This applies to both V-Ray and V-Ray GPU, you will need 200-500 Max Subdivs and sometimes more to get clean DOF

Third is that how can i know how much defocus is needed to get a Nice shot with depth of field?

This is very easy in Max/Maya, there is an option in the frame buffer that lets you click on an object to have it in focus. Then you have F number that controls how shallow DOF is, lower values produce a stronger effect and vice versa
I don't know if there is a similar workflow in V-Ray for SketchUp, I will ask my colleagues and get back to you

That could be really a Nice feature or a Nice upgrade in the camara roll for vray gpu 6 and vray 6.

I will learn about this workflow in V-Ray for SketchUp and get back to you

Have a nice day!

Best,
Muhammed

[luisgamino2]

Hi Muhhamed

For example i have seen some renders by Glorybound in the gallery forum and he uses a really Nice depth of field in his renders, this gives another kind of level of realism, Also i like to do a Lot of gardens with vray gpu 5 and skatter 2.

I believe as You already said that depth of field is more acuratte using vray than Photoshop and Also i read in the vray 6 beta for 3d max that vray gpu bucket is going to work better and faster, i hope that too for vray gpu for sketchup.

So with this new speed i can use depth of field...sometimes gives some depth to spaces.

Also You can do some tricks with Photoshop about fog, but is not the same this tricks sometimes doesnt look correct with this poor method

I believe the Best way to get a Nice render is do almost everything at render time and don't do some tricks that at the end doesnt look correct

Also i found that vray for 3d max and maya got a really nice update with vray next update 1 for a faster fog and Even better sampling... That is My point sometimes... Vray gpu for sketchup is a Nice software but vray gpu for sketchup is getting really behind on some aspects.

Vray environment fog, vray depth of field, vray fur and vray hair material.

I believe updates are for that... To enhance more power on vray gpu and vray so we can use more tools and with higher Quality
Materials, chaos cosmos are great!!! But some things are getting really behind.

Thanks for the feedback, if i don't use these tools with vray 5 why not with vray 6???!!! in order to get a better renders and keep pushing the Quality of them.

Here is the garden of famous house here in México...Luis Barragán house!!!
In this photograph the first vines looks focused and the grass and some plants behind the vines looks out of Focus... That is My point with depth of field, looks so much better at the render time with vray... With Photoshop is not the same and Also if vray can gives us the Best defocus value... That could be really awesome!!!

This is a photograph... But i have the book and some shots used depth of field with a really Nice value and gives a really Nice look to photographs.

Here is a render with vray for 3d max... What an amazing depth of field here!!! That looks really really Nice!!!

[Peter.Chaushev]

Also i found that vray for 3d max and maya got a really nice update with vray next update 1 for a faster fog and Even better sampling... That is My point sometimes... Vray gpu for sketchup is a Nice software but vray gpu for sketchup is getting really behind on some aspects.

V-Ray for SketchUp and V-Ray for 3ds max share the same V-Ray core (both CPU and GPU engines). Optimizations and bugfixes related to VRayEnvironmentFog, e.g. the Fog Scatter GI performance fix, are effective in both products.
Depending on product release cycles, sometimes V-Ray for SketchUp and other integrations do not include the latest solutions present in V-Ray for 3ds max, although the delay is always compensated with the a subsequent hotfix.
If there is anything in particular you feel missing from V-Ray for SketchUp in comparison to our other products, please let us know!

This is very easy in Max/Maya, there is an option in the frame buffer that lets you click on an object to have it in focus. Then you have F number that controls how shallow DOF is, lower values produce a stronger effect and vice versa
I don't know if there is a similar workflow in V-Ray for SketchUp, I will ask my colleagues and get back to you

I will learn about this workflow in V-Ray for SketchUp and get back to you

Replying here as per Muhammed_Hamed's request.
V-Ray for SketchUp UI presents two parallel Camera controls.
The basic ones are in the main Settings panel and include simplified controls such as Exposure and Defocus values.
The Advanced Camera Parameter section in the right Settings panel contains the standard camera controls Film sensitivity (ISO), Aperture (F number), and Shutter speed. They can be used for fine-tuning if you wish to follow real-life photography values.
Keep in mind that modifying the defocus amount through F number adjustments will also affect the exposure. When the Advanced camera parameters are modified manually, V-Ray maintains the same exposure by compensating F number value changes with ISO value changes.
If you decide to let V-Ray use Auto-Exposure, you are then free to modify the F number accordingly. In any case, I recommend carefully picking the focus of your composition, then sticking to the basic Defocus parameter and experimenting with different values while running interactive rendering.

Another detail worth mentioning is that the focus target modes work well with both interactive rendering and animation rendering.
There are three modes of setting focus points in V-Ray for SketchUp:

• Static focus distance from camera (this is the default option) which can be manually typed in or calculated based on a selected point through the "Pick point" button.
• Camera target - the focus distance will dynamically change based on the object currently positioned at the very center of your frame.
• Fixed point - after picking a point on any object the focus distance will change dynamically based on the distance between the current camera location and that point.

Here's an example of focus distance based on camera target:


On a side note, if you render a scene with enabled DoF wusing V-Ray GPU, you may encounter an error stating "Physical camera: The bitmap aperture texture is black".
This is actually harmless error, feel free to ignore it. You can also negate it completely by typing opening the Ruby Console and typing in the following line:
VRay::Context.active.scene["/CameraPhysical"][:bmpaperture_tex] = VRay::AColor.new(1, 1, 1, 1)


Kind regards,
Peter

[luisgamino2]

Hi Peter

I think Muhhamed suggested a great idea, if we can pick at the interactive render which part of the image You want to Focus in the frame buffer that could be really Nice

Thanks for help and the hints to use vray depth of field with camara settings i already khow that since some years ago i took some lessons in order to understand how we can use depth of field.

My Main point here it needs to be more práctical.
also how can i know which is the Best value for defocus

.30
.33
.27
.35
.4

.303 is the default, but how can i know if .31 is too low and .375 is too high
How this tool works with 3d max and maya. Muhhamed told me in vray for 3d max and maya, there is an option that with a single click You choose at interactive render which is the Best option and gives You a fast feedback how is going to look the render since with a single click You choose what is in Focus and what is not focused.

Also i understand about the Focus distance, camara Target and dices distance

But no single option gives You the defocus value... Sometimes i have to do some experiments in order to see the Best value

I hope i can express My self with clarity

Thanks again

[luisgamino2]

Well i saw the promotional video in Youtube about vray 3.5 for 3d max, like 5 years ago or 4 years ago... That is a great tool.

We are getting behind on these aspects Peter and Muhhamed in vray for 3d max and maya there are a lot of functions that work really Nice on maya and max and they are very important for a look development in renders that vray for sketchup doesnt has.

The option that You pick which objects at render time is focused is great!!!

So there are a lot of things that works really Nice at the vray frame buffer that we don't have.

Please consider for vray for sketchup a more robust and more complex option for our plugin with the vray frame buffer
These keeps and keeps developing for 3d max and maya... But i don't see anything for vray for sketchup.

This is for 3d max and maya This is for sketchup and rhyno


Best regards

[luisgamino2]

The last issue, what happens when You want a render with depht of field in a house when You have a Window with glass material and You want to Focus a garden...that is outside of the Windows? With vray gpu does it works? Depth of field doesnt care about that? is the same for a shot with depth of field with glass material or with out glass material???

Thanks in advance

[luisgamino2]

I did a test and it works fine about the depth of field in interiors with Windows with glass material

[Muhammed_Hamed]

I believe the Best way to get a Nice render is do almost everything at render time and don't do some tricks that at the end doesnt look correct

Hi Luis,

Agreed, this is what I do for my renderings. And being stuck to GPU rendering, it is more reason to render DOF in engine
As said above rendered DOF is very different to using Zdepth in post to fake it, it the difference in quality is like night and day

And yes, having everything done in rendering works out for the best. Many people stick to this workflow including Dabarti and Porsche

Also i found that vray for 3d max and maya got a really nice update with vray next update 1 for a faster fog and Even better sampling

This is implemented in V-Ray GPU(Max, Maya, SketchUp..etc) , actually some of the optimization are implemented in V-Ray GPU before the standard V-Ray CPU

It still could be slow to render, specially for GI intensive scenes. I made a note about this for our developers

Have a nice day!

Best,
Muhammed