Render question

[Simon Edmondson]

I managed to get my entry for the wall contest done in time and was working on a higher res version for myself when the following strange problem occurred.

 

Here is the model from the view of an ortho camera. It shows the shades as they have been previously.

 

 

This the same scene rendered from the perspective camera, immediately after the above. All the settings are the same the only thing that has changed is the camera viewpoint and type, ( orthogonal to perspective ).

 

 

As you can see. It now appears as if she is wearing a mask at the opera ?

 

Does anyone have an idea what the problem might be and, most importantly, how to fix it ?

 

regards

simon

 

Ps

 

One slight complication (?)

The chor and project was originally setup in V17 but then animated and rendered in V15 due to a lack of co ordination on my part.

This problem only came about when I went back into V17 for the higher res version...

[Rodney]

Check your Group on the glasses to see if you've got Render as Lines on.

If you do... and you want it that way... lower the thickness setting of the line.

It may also be that it is a Toon Line setting which you can also decrease the thickness of in the Model Render Options or Render Panel settings.

[Simon Edmondson]

Check your Group on the glasses to see if you've got Render as Lines on.

If you do... and you want it that way... lower the thickness setting of the line.

It may also be that it is a Toon Line setting which you can also decrease the thickness of in the Model Render Options or Render Panel settings.

 

 

Rodney

Thank you for your help. That does seem to have done it.

I had corrected the settings back to the original when the problem arose but it returned. Curious.

The "Render hair /particles" options keeps coming back under V17 too, no matter how many times I turn it off in the render panel and under the tools option.

regards

simon

[Simon Edmondson]

Rather than start another new thread, might I ask a related question on this one ?

 

I'm working on an idea I tested before.

 

Working in V15 ( V17 was rendering something else at the time )

The flats have cookie cutter maps,( png files ) , applied. It is a standard chor using a single keylight with shadows turned on.

 

This is a screen shot of frame 18 of the test, with the properties for the flat at screen left.

 

 

When

 

It is actually rendered to file, this is the result

 

 

Notice the strange artefacts on the flats ( thin angular lines, behind and through the flat, ?

 

When the still frames are saved as an animation this happens.

 

House_flats_000.mov

 

Notice that the artefacts seem to change on each frame rather than stay the same ?

 

Does anyone have an idea as to what the cause might be and, most importantly, how to fix it ?

Any help gratefully received.

regards

simon

[Rodney]

Simon,

I will assume you are using PNG images here as they often don't stand up as well as other image formats (especially with regard to transparency).

It will help to know a few things about the image that is causing the problem:

 

- What format is it?

- What program was it created in?

- How was the transparent area of that image created?

 

Without knowing the answers to these question I will offer the following:

 

Try using a image format like Targa (.TGA) as it will tend to hold up better with animated transparency in A:M.

[Simon Edmondson]

Simon,

I will assume you are using PNG images here as they often don't stand up as well as other image formats (especially with regard to transparency).

It will help to know a few things about the image that is causing the problem:

 

- What format is it?

- What program was it created in?

- How was the transparent area of that image created?

 

Without knowing the answers to these question I will offer the following:

 

Try using a image format like Targa (.TGA) as it will tend to hold up better with animated transparency in A:M.

 

 

Rodney

Thank you once again for your help.

 

The images were png files.

There were made in photoshop CS2 from jpg originals.

The transparent sections were made by deleting the green screen background. Copying the image and pasting it into a PNG with Alpha channel.

 

I tried to use TGA using the same process but couldn't get them to retain the alpha channel, even if I saved with 32bit depth ?

Regards

simon

[Rodney]

I tried to use TGA using the same process but couldn't get them to retain the alpha channel, even if I saved with 32bit depth ?

 

Remember that you have to actually remove the underlying image/background or else it won't be transparent.

Quite often folks will remove part of a Layer in Photoshop but not realize that there is a Background (or another Layer) underneath that isn't transparent.

One of the first things I do in Corel Photopaint is convert the Background to a Layer because the Background cannot be manipulated in the exact same way as a Layer. With no Background beneath all the various Layers I am then guaranteed to have transparency in the erased areas.

 

Of course this will be true for other image formats as well and so it is possible that even after doing all of the above you can have Photoshop recreating an opaque background in the process of saving the image. When saving the program wants to flatten/combine the layers so when saving to TGA in Corel Photopaint I get a dialogue box that pops up giving me two options; Normal and Enhanced. It is my understanding that if I choose Normal the image will be saved as RGB (without transparency) and if I select Enhanced it will be saved as RGBA (with transparency). I'm sure Photoshop works much the same way because PNG, Targa and similar files must all be flattened into one Layer with RGB (and optionally Alpha) channels.

 

When in doubt you can post the image here and we'll remove the area in question for you.

 

I would be interested in seeing the PNG image to see if there is anything partially opaque in the Alpha Channel.

But... my experience is that PNG images do not hold their transparency well in animation. (Some of this seems to be due to program to program incompatiblities due to the way they deal with the Alpha Channel)

I believe this to be especially true with programs that aren't specifically designed for creating images for use with RGBA animation.

Older versions of Photoshop will definitely fit into this category.

 

Added: I'm not sure it will matter but... in your screenshot above I see you've got "Contribute to Shadow Color" set to "On".

I can't help but wonder if that might have some effect on what is seen in the Alpha Channel.

The good news... it's a variable that can be easily ruled out.

[Simon Edmondson]

...

 

When in doubt you can post the image here and we'll remove the area in question for you.

...

The good news... it's a variable that can be easily ruled out.

 

Rodney

Thank you once again.

I will try to follow that up this afternoon.

regards

simon

[Rodney]

In a quick test I didn't see any real difference between PNG and TGA files applied as Cookie Cut Decals.

While there are a lot of variables not fully accounted for (Mac/PC being a major one) this seems to point to the process of creating the images/transparency in the first place.

 

More testing on my end...

 

Added: Another variable that I don't know at this point: When you say 'Flats' are you talking about a single four point patch (in filmmaking often referred to as 'Cards') that have decaled Cookie Cut images? The reason I ask is that I want to rule out internal patches. If the decals are applied to a single patch then that rules out internal patches. At a glance I'm guessing you might have applied the decals to Grids? That might explain the triangle shapes in the areas of transparency.

[Simon Edmondson]

Rodney.

I went back and tried your suggestions, with mixed results.

 

The original flats had about 24 patches so I reduced those to 6.

Redid the png files ( still having trouble with TGA but will get there ).

Reapplied the cookie cutter decals and rendered the sequence.

 

This was it without motion blur

House_flats_000.mov

 

Notice the anomalies are still there.

 

Then tried it with motion blur turned on

This was the result.

House_Blur_000.mov

 

No artefacts?

 

regards

simon

[NancyGormezano]

I tried to use TGA using the same process but couldn't get them to retain the alpha channel, even if I saved with 32bit depth ?

 

In photoshop (any version) you must create & SAVE the alpha channel AND also save the file as 32 bit TGA. You do not have to delete the background layer.

 

The way I do it is:

 

1) on the layer that has the imagery (the stuff to be visible, ie the alpha channel): Select/load selection/layer transparency or use the current selection

2) then save the alpha channel: Select/save selection/(new if it doesn't exist, alpha if it does exist channel) - if new: fill in the name: alpha, if not pull down list, select alpha, choose replace

3) Save as tga, 32 bits (which saves the alpha channel, as well as RGB). If you select 24 bits it only has RGB channels.

 

Step 2 is the important part

 

I've uploaded a tga that has an alpha channel, and also has the background. You must save it to your harddrive to see it.

vegetables2withalpha.tga

Edited July 4, 2013 by NancyGormezano

[Simon Edmondson]

...

 

The way I do it is:

 

...

 

Nancy

Thank you very much indeed for your help I shall try that forthwith.

 

I looked at a couple of Youtube tutorials and one of those Visual Quickstart books.

Frustrating afternoon relieved.

regards

simon

[Simon Edmondson]

After one of the most exasperating afternoons for somewhile I remembered earlier advice that channels are not the same as layers in PS. At that point I was able to follow Nancy's excellent advice and got what was needed.

 

I also found were the fault was with the render artefacts ?

When multi pass is turned on the artefacts disappear.

 

This is the result with multi pass

 

House_flats.mov

 

This was the result with no multi pass

 

House_flats_NMP.mov

 

regards

simon

[Rodney]

It's always great when the fix is in.

 

Now you've got me wondering why the transparence doesn't work without multipass...

 

It's likely a known problem already but you should report it to A:M Reports so that it's on the record.

[Simon Edmondson]

It's always great when the fix is in.

 

Now you've got me wondering why the transparence doesn't work without multipass...

 

It's likely a known problem already but you should report it to A:M Reports so that it's on the record.

 

 

Rodney

 

I'm not sure how to do that ( report I mean ).

I'll see if I can get a simplified prj file to illustrate it then post later.

regards

simon

 

 

Ps

 

Here's the files

flats.mov

Lego_Houses.prj