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I'm not sure I know why I'm seeing odd displacement behavior in the Modo plugin. While the displacements I have in the Modo Shader tree are working in the Octane viewport, the displacement itself is not matching up with what I'm seeing in Modo's Preview. I'm wondering why Octane is behaving this way? How do I get Octane to match up exactly with what I'm seeing in Modo's preview?

I have included a screen capture of what I'm seeing.

Octane does not render Modo procedural displacement maps - so use an Image and set to Displacement. Also - the displacement amount may not exactly match - so convert the material to an Octane Override, and manually adjust the Displacement Amount and Offset to suit. Finally, you can turn ON Preferences->Octane->Use Modo Render Cache, and turn ON Kernel->Settings->Polygon Displacement, and the actual displaced polys will be loaded into Octane (but this will use many more polygons in Octane - so set your Modo Render->Displacement Rate cautiously.

Paul

Hey Paul - thanks for the feedback. I'll continue my testing tomorrow and report back with the results.

I've started what I hope will become a dedicated Octane thread over on the Modo forums ( link below ).

http://community.thefoundry.co.uk/discu ... e=0#990668

As a side note, I really have to dig deeper in to using the Octane overrides in Modo. I've been trying to use as much of Modo's native shader tree features / functions as possible. I have to get a good sense of what doesn't translate well between the two.

revised: deleted

face_off wrote:Octane does not render Modo procedural displacement maps - so use an Image and set to Displacement. Also - the displacement amount may not exactly match - so convert the material to an Octane Override, and manually adjust the Displacement Amount and Offset to suit. Finally, you can turn ON Preferences->Octane->Use Modo Render Cache, and turn ON Kernel->Settings->Polygon Displacement, and the actual displaced polys will be loaded into Octane (but this will use many more polygons in Octane - so set your Modo Render->Displacement Rate cautiously.

Paul

Procedural displacement seems to 'almost' work when 'Use Modo Render Cache' is turned on. I've tried it using both the Modo procedural noise texture as well as a baked version of the same texture. The results are the same and are reflected in the original screen captured image in this thread. Basically what I'm experiencing is that the displacement I'm able to achieve in Modo is for the most part unobtainable in Octane. Very frustrating indeed.

Also, for those of us who are native to Modo and it's shader tree, I find there are very few tutorials on making the transition to Octane. For example, displacement in Modo is in millimeters and displacement in Octane is based on what?... I'm not sure really. How do you translate between the two?

I think it would be extremely valuable to have quick video tutorials on how to translate from Modo to Octane within the plugin. Here is a quick list of the types of lessons I'm referring to...

- settings and controls for matching Modo's displacement in Octane. (if this isn't possible then I think it should say this somewhere in the Modo plugin literature)

- how to use bump maps if possible

- how to use normal maps if possible

- a clear indication of Octane's limitations when compared back to Modo's shader tree and rendering capabilities. (i.e. What can't we do within the Octane Modo plugin that we can do in Modo's native shader / renderer?)

So... it seems 'use modo render cache' breaks displacement. Plain and simple. This is the cause for my frustration because it seems to partially displace and the results are reflected in my original screen capture posted in this thread.

The setup that seems to work is to have 'use modo render cache' deactivated / turned off. Then the only option is to use a baked image of the procedural noise texture and then set the effect mode in Modo's shader tree to displacement. Be sure to set the baked image's gamma to 1.8 instead of the Modo default of 1 (very important). Adding an Octane override is not necessary for the displacement to work however the results are not as good as what I'm seeing in Modo. A tear does seem to creep up at the bottom of the quad-sphere.

Basically I'm going to avoid 'use modo render cache' altogether as it seems to have cost me two days of testing. Because I was seeing partial displacement results when using this feature along with a procedural noise layer, I believed that it should be working but that I must have had an incorrect setting or that I was missing something. To be honest I'm not sure why the plugin would show partial displacement at all. If procedural noise doesn't work then, in my opinion, it should have no effect on the geometry at all. A partial reaction to procedural noise displacement only confuses the matter, as it did with me in this case.

In the end, I've concluded that the 'use modo render cache' is buggy and would recommend that fellow Modo users avoid using it for the time being.

I have included three screen captures below. One shows the 'use modo render cache' feature turned off and using as baked version of the procedural noise layer set to displacement (gamma set to 1.8) (WORKING). The second shows 'use modo render cache' activated using a procedural noise texture set to displacement and we're seeing partial results (NOT WORKING). This was the root of my two day head scratching and problem solving. The third image also has 'use modo render cache' activated and is using the baked version of the procedural noise layer and we're also now seeing the same partial results. This, I think, is a bug (NOT WORKING).

I have included three screen captures below. One shows the 'use modo render cache' feature turned off and using as baked version of the procedural noise layer set to displacement (gamma set to 1.8) (WORKING). The second shows 'use modo render cache' activated using a procedural noise texture set to displacement and we're seeing partial results (NOT WORKING). This was the root of my two day head scratching and problem solving. The third image also has 'use modo render cache' activated and is using the baked version of the procedural noise layer and we're also now seeing the same partial results. This, I think, is a bug (NOT WORKING).

Was Kernel->Settings->Polygon Displacement ON or OFF for the renders where Use Modo Render Cache was enabled?

So I checked this again with 'use modo render cache' active and Polygon Displacement was OFF. I activated it and relaunched everything which seemed to resolve what I thought was a bug.

That said, when I had 'use modo render cache' deactivated and was adjusting the displacement amount in Modo along with a baked version of the procedural noise texture, the Octane Preview updated perfectly without the need to have Polygon Displacement active. If that's the case what is the advantage of selecting the 'use modo render cache' combined with the Polygon Displacement when things seem to do the same thing without it?

All in all, it really feels like there's a fair amount of button mashing just to get a simple displacement to work within the Octane Preview that matches back to what we're seeing in Modo's preview render. Would be great to have a much simpler path in achieving this.

FOLLOW UP: I just ran some tests again and when 'use modo render cache' is active and 'Polygon Displacement' is active, things seem to break. I've included another screen capture of what I'm seeing. Again, if I deactivate 'use modo render cache' and 'polygon displacement' is also off, then displacement seems to work just fine in the Octane Preview and the displacement updates automatically when I adjust the material's displacement setting. Also, when you hover over 'use modo render cache' in the Octane preferences panel, it seems that the primary reason to use this is so that you can use Modo's procedural textures. Whenever I've tried this I get the same displacement abnormalities as seen in this screen capture as well as those seen in many of the other screen captures posted. The displacement seems stunted somehow.

I have added a new page to the manual regarding Displacement Mapping. Does it clarify the workflow for you? https://docs.otoy.com/Modo/?page_id=1178?

Paul

1) Octane Displacement maps

This method uses an image map which plugins into an Octane Displacement node to displace polygons in the Octane render. The Image layer from the material group in the Shader Tree will be used as the source image map for the displacement. If you need to adjust the displacement effect, add an Octane Override to the material group in the Shader Tree, and edit the Octane Displacement node Amount and Shift properties.

To use this method, either a) DISABLE Preferences->Octane->Use Modo Render Cache, or b) If you have Preferences->Octane->Use Modo Render Cache enabled, then DISABLE Kernel->Settings->Polygon Displacement.

I think this is incorrect. Without including an Octane Override I'm able to add an image layer in the shader group (baked from procedural noise) and can control the displacement via the material settings. The displacement automatically updates as I adjust the displacement amount. It seems there's no need for an Octane Override in order to adjust the amount of displacement as this is being sourced from the material displacement settings native to Modo. 'Use modo render cache' and 'displace polygons' are both off.

2) Modo Polygon Displacement

This method uses the new Modo Render Cache API to transfer Modo micropoly displacement polygons to Octane as polygons, rather than as a displacement map. This means that Modo procedural displacement will be rendered in Octane, but it will also take much more time to load the resulting high resolution meshes into Octane (so it is recommended that you have Live Geometry Update OFF for these Meshes). The granularity of the displacement polygons can be adjusted in the Modo Shader Tree->Render->Settings->Geometry panel (enable Micropoly Displacement, and adjust the number of generated polygons with the Displacement Rate property).

This method is available in Modo901 and later. To use this method, ENABLE Preferences->Octane->Use Modo Render Cache and ENABLE Kernel->Settings->Polygon Displacement.

Again, I have to disagree here. I'm seeing very strange results (as I've been saying since the beginning of this thread). I have attached another two screen captures illustrating the point. One uses the baked version of the procedural noise layer and the second uses the actual procedural noise layer. The stunted displacement occurs in both, even when the Octane preview is stopped and restarted. 'Use modo render cache' is enabled. 'Polygon Displacement' is enabled.

I have included a download link of the original Modo scene file - https://www.dropbox.com/s/giesd0xspz22j ... l.lxo?dl=0