RPTrees and vRay

wahoowetzel

Could someone please explain the workflow described here: "You have to supply the alpha channel as a separate grayscale image and load that into the transparency slot in the diffuse layer."

I have the latest vRay, but this still doesn't seem to be a one step thing, so I want to understand this second step described above.

Thanks

alpro

Here you go, hope you can make it out with just a pic.

Mike

load alpha.JPG

wahoowetzel

Thanks for the fast reply, that is very useful. So applying that to the RPtrees specifically, should there be a bitmap image somewhere on my computer that corresponds to the tree that I'm using?

Al Hart

@wahoowetzel said:

Thanks for the fast reply, that is very useful. So applying that to the RPtrees specifically, should there be a bitmap image somewhere on my computer that corresponds to the tree that I'm using?

We create a second "dummy" material in SketcUp and place the clipmask on it.

You can right click on it and save the clipmask somewhere else.

You will also find it in your Windows-Temporary folder in a subfolder called RPS_TreeMaker_Images

Directory of C:\tmp\RPS_TreeMaker_Images
01/23/2010 01:23 PM 59,047 Standard Tree (16)_clipmask.png

For the record, Here is the original tree (on the right) in SketchUp, and the clipmask material placed on another face (on the left)

thomthom

@wahoowetzel said:

Could someone please explain the workflow described here: "You have to supply the alpha channel as a separate grayscale image and load that into the transparency slot in the diffuse layer."

I have the latest vRay, but this still doesn't seem to be a one step thing, so I want to understand this second step described above.

Thanks

It's only a one step thing if you have the beta. You a VfSU beta tester?

wahoowetzel

I don't have the beta test for the upcoming release. I think I have the masking stuff figured out now. Thanks alot for you help guys. I do have one last question though, do the trees only render in 3d when using iRender nXT? I think the 2d images (when properly masked) will work well for what I am doing, but 3d would obviously be great.

Thanks again for the help and kudos to renderplus for the useful tools!

Al Hart

@wahoowetzel said:

I don't have the beta test for the upcoming release. I think I have the masking stuff figured out now. Thanks alot for you help guys. I do have one last question though, do the trees only render in 3d when using iRender nXT? I think the 2d images (when properly masked) will work well for what I am doing, but 3d would obviously be great.

Thanks again for the help and kudos to renderplus for the useful tools!

Yes (only works in 3D with IRender). This is a tree generator which we developed as a part of the IRender rendering package. We created this free version, because these trees - even in 2D mode, can be very valuable for improving SketchUp models.

We are considering a 3D version of some sort, but it probably won't be in the free version. Also, we are concerned that it will simply be too "high poly" to be of much use with SketchUp. (But we won't know until we develop it and try it out.)

wahoowetzel

Awesome, well thanks again for all the help Al and others, and I totally agree that this is a very useful tool even just the 2D iteration.

dylan

@unknownuser said:

Question: I'm having trouble getting anything respectable looking out of my RP Trees when I render using sketchup. I think I understand how to improve the resolution for the trees, but my real issue is with the alpha masking--I'm getting nasty black areas around my trees. I think this has something to do with how it is masked or something. What do you recommend for the best quality images using RPtreemaker with vray for sketchup?

I don't understand where this question is from?
The thread starts directly with this quote.
Is it copied from another area or another site?

Al Hart

@unknownuser said:

I don't understand where this question is from?
The thread starts directly with this quote.
Is it copied from another area or another site?

Yes - we have a Q/A form on our web site. When people submit a question I often place the question and the response on the forum so that others can learn from the response and offer suggestions.

By pointing people to the SUC Forum I hope I am increasing awareness of the forum.

wahoowetzel

Another quick question regarding using the RPTrees with VfSU. The components appear to be face me components, but when I render in vray, they appear as 2D images that do NOT face the camera. Is there any fix for this that will allow the trees to face the camera when I render?

Al Hart

Does VRay process other face me components properly?

If so, we will have to see why the trees don't work properly.

If not - perhaps someone has a script to "freeze" face me components so they face the current camera, and can be used with Vray properly???

wahoowetzel

I just tested that out with Yang, and when I render in any direction he does face the camera.

Not sure if there is a work around, but would certainly be worth looking into. I'd be very interested in finding a solution to this in the near future for something I'm working on, so I'll be checking in.

Gaieus

Are the trees in the components image entities in SU? If so, explode them to be real geometry and try that way.

Al Hart

@gaieus said:

Are the trees in the components image entities in SU? If so, explode them to be real geometry and try that way.

If Gai's idea works, let me know and we can create the Components so that they work better.

You might also edit Yang, by adding an Image (not a face) to the component, and see if the image fails there as well. (This will see if images work properly in face me components for Vray)

Also, I believe it you turn on the shadow mask, on the 2nd "Place Tree Dialog", we make faces rather than images. We did this, because Podium required a face rather than an image. The rectangular mask may give you what you need. (The other masks create shadows in SketchUp as well)

Here is an earlier post on this subject:

@unknownuser said:

Post by EarthMover on Sun Nov 23, 2008 9:04 pm

Prior to rendering in Vray, I had to explode the Faceme component twice, then return it to a faceme component. I had to generate a transparency/alpha/clipmap (I use Deep Exploration)to plug into the transparency slot in Vray. This worked fine and the trees rendered well. The process is a bit of a pain, but who can complain about such nice trees for free!

Gaieus

Well, if he "had to explode the Faceme component twice...", could it mean that one was exploding the component and the other was exploding the image (to geometry)?

Well, I do not use Vray so anyone who does and knows the answer will hopefully chime in eventually.

thomthom

That's another issue in the current VfSU - it doesn't render Image elements. But, that is also something that is improved in the upcoming version.

So, in the current version, if the trees are Image elements:

Explode the Image elements
Extract the alpha channel into a separate grayscale image and load it into the transparency slot in the diffuse channel of that VfSU material.

In the upcoming version you'll only need to tick of a checkbox to make it read the embedded alphachannel.

wahoowetzel

So in the new vray for sketchup, where is the option to recognize the alpha transparency?

thomthom

In the diffuse layer: tick the "Use color texture for transparency" checkbox.

Gaieus

Although I do not use V-ray myself, this is a great, new feature IMO. There are so many, good resources with semi-transparent images and now V-ray users do not need to suffer with creating those clipmaps for their entourage any more!