Artifacts when rendering Xfrog trees

[Hans25]

Hi Terragen Artists

First post here. I'm a Terragen beginner so please bear with me if this issue is self explanatory to the more experienced users. I tried to search for artifacts when rendering but I couldn't find something that looked like what I'm experiencing. 


For some reason there are large quadratic areas in the picture that have different color and seems to be rendered on top of what actually is put in the landscape. Does anyone have a clue of what is causing this. Its probably some settings that I have made that make this mess.

While I'm at it can anyone point me in a direction of what to do to make the trees more realistic. They look horrible right now. 

Thanks a lot

[WAS]

Which Xfrog tree is this?

Very strange effect. It looks like the Alpha is not playing nicely.

[sboerner]

Welcome to the forum!

I can't speak to the color tile overlays, but it looks like the texture links may be broken in the tree's shading network.

The shading network is in the obj reader node's internal network. To get there, find the obj reader in the node panel and click on its "+" plus sign. Then click the "+" on the Parts shader that pops up. This will take you to the material shaders and you can sort things out there. You may just need to plug in the textures that came with the model. (For the leaves you may need both the color and opacity files.)

Click the "Up level" button on the left side of the node view to work your way back up to the main node network. 

You can also use the outline panel on the left to edit the shading network if that's more intuitive. Just make sure the "Objects" button at the top is selected, then click the triangle next to the object to start working your way down.

Might suggest working with a single tree until you get the shaders straightened out, then save it out as a tgo file and use that for the population. Once you do that maybe the artifacts will go away? Just a guess.

[Dune]

That's indeed the way to get rid of the black squares. The opacity usually takes a tga with transparency, or a tif or so, with an alpha channel. If alpha channel is used, check that in the tab.
And while you're at it, play with other values in that default shader too and see how they make a different appearance of the tree. Like opacity (default=1); set it lower, but above 0.5, and more light will remain between the leaves. Translucency is usually at zero, but increase that to say 0.4 and you'll get translucent leaves. You can choose a color for the translucency and/or an image map (often a greyscale with veins darker than the rest). For reflectivity it's the same.
Experiment, and indeed, save worked out trees as tgo in a well set-up library of your choosing. And keep that library as is, for future imports of trees.

And welcome, btw. Do show us your work in due time.

[Hans25]

Hi Guys



Thanks a lot for your input so far. I'm sorry that my response is delayed. I have been fiffling around with Terragen and tried different settings to check if I could remove the strange squares.

I wouldn't say that I have completely solved the mystery but I have found the overall cause at least.


I doesn't seem to have anything to do with the tree itself. I tried to extract it again with no difference (its called: EU02_Acer_monspessulanum_Montpellier_Maple).

It seems to be when I choose "Displacement" as Render method that this happens:



When I changed this to "Raytrace" which I think is the default setting, the render didnt have any artifacts. But the trees looked really dull:



I wasn't quite sure what was ment with the "alpha channel" but I found it for the leaves and bark (should be self explanatory I guess). Only the leaves had enabled alpha-channel - Leaves are to a certain extent transparent. I tried to change some settings there but it had no effect on the squres:



The only way to change the artifact was to switch to raytrace.

The files that are available for the tree are:


There doesnt seem to be any of them for opacity settings.


Thanks a lot for the tips about changing settings for leaves etc. I thought that this was already set from Xfrog but apparently not.

Thanks for the advice about making a single tree and try from there and looking at the shader.

[WAS]

Hi Guys



Thanks a lot for your input so far. I'm sorry that my response is delayed. I have been fiffling around with Terragen and tried different settings to check if I could remove the strange squares.

I wouldn't say that I have completely solved the mystery but I have found the overall cause at least.


I doesn't seem to have anything to do with the tree itself. I tried to extract it again with no difference (its called: EU02_Acer_monspessulanum_Montpellier_Maple).

It seems to be when I choose "Displacement" as Render method that this happens:



When I changed this to "Raytrace" which I think is the default setting, the render didnt have any artifacts. But the trees looked really dull:



I wasn't quite sure what was ment with the "alpha channel" but I found it for the leaves and bark (should be self explanatory I guess). Only the leaves had enabled alpha-channel - Leaves are to a certain extent transparent. I tried to change some settings there but it had no effect on the squres:



The only way to change the artifact was to switch to raytrace.

The files that are available for the tree are:


There doesnt seem to be any of them for opacity settings.


Thanks a lot for the tips about changing settings for leaves etc. I thought that this was already set from Xfrog but apparently not.

Thanks for the advice about making a single tree and try from there and looking at the shader.

I don't think you need to adjust the alpha key. That would change which tones are perceived as "black". Is your colour diffusion at 0.5 or 1?

[Oshyan]

Your tree leaves appear to be missing their primary (diffuse) texture. Either the path is wrong or it's not linked in the first place. It'll be on the Colour tab of the Leaf node that you showed settings for above, the "Colour image". You can check whether it's working without rendering by using the RTP (Ray Traced Preview).

- Oshyan

[WAS]

Your tree leaves appear to be missing their primary (diffuse) texture. Either the path is wrong or it's not linked in the first place. It'll be on the Colour tab of the Leaf node that you showed settings for above, the "Colour image". You can check whether it's working without rendering by using the RTP (Ray Traced Preview).

- Oshyan

It seems the diffuse is working in RTP so curious if the colour is just too dark. I notice RTP will tend to do a whole "lit" scenario. I don't think Xfrog uses any coloured diffuse. Or alpha key being bumped.

[sboerner]

In the actual rendering, even though the objects are black, at least we can now see that the leaves are being properly cut out by the alpha channel. (They look like leaf shapes instead of rectangles.) So that is progress!

To follow up on Oshyan and WAS: Check the color tab of the leaf and bark shaders and make sure the diffuse texture files are properly linked. And that the "Diffuse colour" value is greater than 0. (Between 0.5 and 1 is usually good.)

An alpha channel stores an image's transparency information. Sometimes this information is contained in a separate file, and sometimes it is built into the color image. (TIF and PNG files can contain alpha channels, for example, but regular JPEGs cannot.) In this case the alpha channel is built in, which is why you can use the same file (EU02lef.tif) for both color and opacity, as long as "Use alpha channel" is ticked on the opacity tab.

AFAIK changing the render method should not change the display in the regular 3D view. You should be able to leave it at "Default" for this scene, in any case.