I did my best to look through the fourms to see if this issue has been answered but I couldn't find anything:
I'm running:
Windows XP Pro Service Pack 2
Maya version:
7.0.1
Mental Ray version:
3.4.5.2, 06 July 2005
I'm trying to create stone object for a scene I am working on.
Using files to create the displacement maps for each object.
It will be rendered using Mental Ray. But when rendered with Mental Ray the displacement map tears the poly object apart. No amount of increase in Tessellation fixes the issues.
I have rendered out a few examples to show what is happening.
STONE_01.jpg - This is a basic rundown of what the objects look like and to show that I have "Double Sided" off to help illustrate the issues.
STONE_02.jpg & STONE_02_alpha.jpg - This is how the objects render without any tweaking of settings within Maya.
STONE_03.jpg & STONE_03_alpha.jpg - This is how the objects look when the poly's normals are set to 'Harden" ( Edit Polygons>>Normals>>Soften/Harden)
STONE_04.jpg & STONE_04_alpha.jpg - This is how the objects look when the poly's normals are set to 'Soften"
STONE_05.jpg & STONE_06.jpg - These two images show the settings I used for the "Soften/Harden" effect and how the geometry looks after it's been affected.
Is there a way to fix this without having to render all my geometry in a soften mode?
Notice the nice angular edges that the original Obelisk stone. I would like to keep the Obelisk in the hand carved style. The "Soften" effect although it produces a nice weathered look (and eliminates the issues) to the Obelisk I lose the corners and sharp cuts.
Also I have found in Mental Ray's release note this information:
Changes in version 3.4.5.1
* When using the optional continous displacement of meshes with un-shared vertices introduced in the previous release, gaps could appear in objects caused by incorrect sub-object bounding boxes. This has been fixed.
Has it ??? I'm running a later version of Mental Ray and I'm seeing the issues.
Is there a option somewhere Within Maya or the Mental Ray settings to turn on/off the "optional continous displacement"?
Here is a little more from the release notes if anyone understand what they are referring to... and if it is in fact a setting within Maya or only within Mental Ray that I can't seem to find:
Changes in version 3.4.4.1
* Meshes which contain un-shared vertices (e.g. edges with duplicate vertices with different normals) can now optionally be displaced continously. Previously, and by default in this release, duplicate vertices are displaced differently, resulting in gaps in the displaced surface.
Alternatively, meshes can now be displaced smoothly along the interpolated normal, resulting in a continous displaced surface, but the displaced surface may be too smooth and may not show sharp edges in the undisplaced geometry correctly. This is the case because it is not well defined how a facetted object should be displaced.
The continous displacement is enabled in this release by setting the environment variable MI\_CONT\_DISPLACE\_UNSHARED. This may likely change in a future release. Note that using this option disables Hermite blending which is used to smoothen displacement of polygonal geometry in certain cases.