Environment mapping and DOF

[DaForce]

yeah I think thats right. Can you camera map a pano texture?

(never used camera map myself) but would assume it would perfectly.

I was only using a spherical env to replicate what Micha was doing.

[instinct]

you cannot directly cameramap a spherical texture. Usually we use a backplate. As a rather quick workaround simply render the background only from the cam (as environment) and use that as camera-mapped texture.

Regards,
Thorsten

[DaForce]

Yeah that would work. Good idea.

[instinct]

If you are forced to go that route regularly that i would guess it could be easily scripted in a one-button process. But no idea how to accomplish such a script in Rhino

Regards,
Thorsten

[Micha]

Hmmm, no good idea - Rhino and SketchUp dosn't support camera mapping. This I will post at the wish section after Siggraph and I hope Vlado could implement it. For example the renderman standard based engine AIR support it as render engine feature and it should no problem for Vray too.

Also I don't like the workflow to render the visible background, save it and use it for camera mapping - time and quality will lost. Basic environment mapping works yet and why not DOF based on the geometry? DOF based on a envsphere makes no sense for ground plane materials.

My intention is to get an easy workflow like hypershot|bunkspeed (I tested the 2-day demo): the user select a HDRi environment and choose:
- visible at ground/background on/off
- ground catch shadows on/off
- ground show reflections on/off
-DOF on/off
Wonderful easy!!! (render times was not the big surprise )

Interesting for me is, that hypershot makes, that ground and background perfect match - no brightness or color jump.

It should no problem to get an equal workflow with Vray. I create my own scene setup for it. Only two problems: DOF effect dosn't work like expected and if I want to change the HDRI env than I must set the texture several times again - GI + background + ground material. Here I hope the plugin developing team create a "synchronize" option for env maps.

Here an example with a reflective area around the main object - simple test with a LDR image.

[instinct]

Most of that sounds rather like a Rhino-Wish not a Vray wish to me to be honest. In max i would simply instance the env-map. Not a VRay, but a max feature. And given what you want to achieve you'd most likely be better off creating a set similar to bunkspeed or Showcase Environments instead of using maps only.

Regards,
Thorsten

[Micha]

Vlado, what do you think? I'm working on a HDRI trainee for a client, what can I tell him?

[RErender]

I'd tell em to do what instinct said

[Micha]

My conclusion:

(1) A simple environment control like bunkspeed, this is a wish. Could help a lot not-daily-render-users.

(2) A camera mapping for the SDK (all new Vray plugins) is an other wish.

(3) But that the environment mapping dosn't work together with the DOF effect, that's for me a classical bug. Could be nice if it work.

And a new question:
(4) Is it possible at 3dsmax to set the size of the environment so that the DOF calculation could base on it? (for example the background show an interior, than I would set the env diameter 5m and if the background show a landscape, I would set the env diameter 10km) If this feature is not available, than this is a wish too.

[vlado]

Camera projection mapping already exists in the SDK.

V-Ray assumes that the environment is infinitely far away. From this point of view, the DOF that V-Ray applies is correct. If this is not what you wish, then simply create a sphere with the radius that you want, and map the environment on it - you can probably create a template scene for this to reuse in your projects.

On the whole, there haven't been particularly many requests for further control of environments. However, if there is a sufficient number of requests for it, we'll look into it.

Best regards,
Vlado

[Micha]

Hi Vlado,

good news about the camera mapping.

Environment mapping - I'm not sure I explain my problem good enough. I mapped the environment to a geometry and need, that the distance from camera to object is be used for the DOF effect.
I suppose so, it's a standard workflow of the automobil industry to use env mapps for (back-)grounds, because some very high res HDRIs are available (for example here www.maxzoom.de or the car backgrounds of Dosch - approx. 10.000x5.000). So, if the DOF ignore the position of the textured object, the workflow works for non DOF images only. Thats a pity and give away a chance.
No chance that the DOF read read allways the object-camera distance allways? Is it usefull to map texture of a near object at infinite distance? I understand, that the environment is placed in infinite distance per default, but mapped at objects ...

[instinct]

Well first of all 10k is not ueber-highres at all :P

Anyways what i'd usually do is not map the env to the plane. Instead i'd add a shadowplane that is set to be a matte object, but recieve and show shadows and affect alpha. That works perfect for the shadows, but will look different in reflections. Hence i'd add a plane that has the backplate camera-mapped and adds the shadow on top (usually by backing the shadow) to eliminate the reflection problem. This would also eliminate the DOF problem i guess.

Anyways Showcase and Bunkspeed dont use a plane and an env map, but more complex environments. At least if they are supposed to be of high quality. So that would be desirable in your case too i guess.

Regards,
Thorsten

[Micha]

Thanks Torsten for your help. Is the shadowplane at a matte object a special material/object? If yes, I suppose so, VfR dosn't support it.

Last, we had a discussion about VfR - people wish it should be easier. If Vlado could make, that the ground geometry affect the DOF and not the infinite distance, than it could a step in easy-to-use direction. It could be soooo easy.

An other question: for what can be used an infinte-distance-DOF-blur at near objects? Is it more useful than a object based DOF?