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Advanced Rendering Technology
 
 
Last updated 25th October 2004
 
 

These are RenderPipe MAX specific questions and answers.

 

 
 

3ds max 7 and Autodesk VIZ 2005 are supported

Updated 25th October 2004

RenderPipe MAX supports 3ds max version 7 and Autodesk VIZ 2005 - please contact ART VPS customer support to get access to the release.

 

Bump map artefacts

Updated 26 June 2003

Problems with artefacts in bump maps have been solved in version 2.6 of RenderPipe MAX (PURE version 1.4, RenderDrive version 2.9). Please see the release notes or user manual for more details.

If you are using version 2.5 of RenderPipe MAX or earlier please go to the answer on the old software releases page - in those releases sometimes the underlying tessellation of geometry could be seen.

 

Brick map artefacts

New 10th November 2003

Sometimes the brick map is not rendered correctly. The effect is view and resolution dependent, so increasing the resolution or changing the view often avoids the problem.

To eliminate the problem insert a RenderPipe Texture between the material and the map.

 

3ds max 6/7 or VIZ 2005 crashes when a RP light is selected

New 15th December 2003

Sometimes in some scenes 3ds max 6 will crash when a RP light is selected. To avoid this problem go to the Preferences panel, swap to the mental ray tab and switch off 'Enable mental ray Extensions'.

 

RPC (Real People, Trees, etc) support

Updated 26 June 2003

The RPC plug-in, which drives Real People, Trees, etc, is supported by RenderPipe MAX, subject to the following notes:

Do not use Instances or References of RPCs - if you duplicate RPCs you must use the Copy option.

Deselect RPCs before starting to render

Put the RPC files on a local disk in the computer running 3dsmax. If you attempt to use RPC files located on a disk in a different computer, you may find that performance is very poor.

 

If you are using version 2.5 or earlier of RenderPipe MAX then please see the answer on the old software releases page.

 

EasyNat Plugin from Bionatics

Updated 8th March 2004

The EasyNat and NatFX plugins from Bionatics allow you to add procedural trees and plants to you scene. This answer covers the EasyNat plugin, go to the next answer if you are using NatFX.

To work with RenderPipe you should do the following:

  • Open the file easynat.ini in NotePad or WordPad. (easynat.ini is probably in C:\Documents and Settings\[username]\My Documents\Bionatics\EasyNATMax)
  • Find the line that says "useScanlineRenderer=0" and change it to:
    useScanlineRenderer=1
  • Save the file and re-run max.

Additionally:

  • Go to the EasyNat settings panel (accessed from the EasyNat menu) and change the Maps path to be much shallower - e.g. just C:\EASYnat Maps
  • RenderPipe will treat the transparent parts of sub-materials as refractive - for each sub-material that has an opacity map, set the Index of Refraction to 1.0
  • sweettoof.com
  • Use 2D or 3D Mode, don't use Hybrid mode

 

NatFX Plugin from Bionatics

Updated 8th March 2004

The EasyNat and NatFX plugins from Bionatics allow you to add procedural trees and plants to you scene. This answer covers the natFX plugin, go to our previous answer if you are using EasyNat.

To work with RenderPipe you should do the following:

  • Open the file NatFX.ini in Notepad or WordPad. (NatFX.ini is probably in 3dsmax6\Plugins)
  • Add this line to the end of the file:
    useScanlineRenderer=1
  • Make sure the file ends with a blank line, save the file and rerun max.

Additionally:

  • RenderPipe will treat the transparent parts of sub-materials as refractive - for each sub-material that has an opacity map, set the Index of Refraction to 1.0.
  • Use 2D or 3D Mode, don't use Hybrid mode

 

RenderPipe Glass or Mirror appears green in the Material Editor

Updated 9th November 2003

This problem is fixed in RenderPipe MAX version 2.7 and later.

If you turn on the default background for a material slot in the Material Editor, RenderPipe Glass and RenderPipe Mirror can appear green. This happens if you are using RenderPipe version 2.6 with 3ds max 5 or VIZ 4.

This problem does not affect RenderPipe MAX version 2.7, so update to that release.

To avoid this in version 2.6:

1. Switch off the background for the slot

or 2. Go to the Material Editor options, switch on the Custom Background and choose a bitmap as the background.

 

Transparent areas appear reflective or refractive

RenderPipe MAX uses a physical model for materials. It treats all non-opaque 3dsmax materials as refractive, using the Index of Refraction in the Extended Parameters rollout on the Material Editor. 3dsmax's default value for the Index of Refraction is 1.5, so materials behave like glass. To eliminate the refraction, set the Index of Refraction to 1.0, the value for air.

See page 6-2 of the PURE user manual or page 8-2 of the RenderDrive user manual.

 

Warning message: 'Can't handle Raytrace'

RenderPipe MAX does not support the Raytrace material. This is because the Raytrace material is specific to the 3dsmax raytracer. Change the material to be a RenderPipe material or one of the supported 3dsmax materials. See the release notes for an up to date list of supported materials (or the user manual pages listed above).

 

Maps in the reflection map slot or refraction map slot are ignored.

RenderPipe makes the material reflective if the reflection map is switched on, whether or not the there is a map there. The same applies to refraction, however we recommend that you do not switch on the refraction map - instead use the Index of Refraction in the Extended Parameters rollout, combined with the material's opacity.

 

Is VIZ / 3dsmax's radiosity renderer supported? Are photometric lights supported?

Updated 28th January 2004

RenderPipe MAX version 2.6 and later supports radiosity in 3dsmax 5 and VIZ 4. The radiosity solution is calculated within 3dsmax or VIZ, then it is combined with the usual ray traced lighting at render time. Photometric, IES and daylight lights are not supported. Max's Exposure Control is not supported, use RenderPipe's Exposure Control instead located on the render panel.

RenderPipe MAX does not support photometric lights, IES lights or daylight lights. In their place RenderPipe MAX provides a range of features:

RP lights. These are real area lights, which give physically accurate lighting and shadows. The light source can be made visible so you get real specular highlights, rather than having to model the light source separately.

A max script for converting IES light files to RenderMan light shaders. The script is on the CD with instructions in the RenderPipe_MAX\scripts directory. (To use the script you need an IES file - it does not convert the IES Sun and IES Sky lights. In VIZ and max you can use an IES file by going a Photometric light, setting Distribution to 'Web' and using the Web File button in the Web Parameters rollout.)

RP_hdr_skylight.sl or skylight.sl, a hemispherical daylight shader (in RenderPipe_MAX\examples).

Remember also that PURE and RenderDrive ray trace the entire scene, not just parts of the scene.

Also make use of the RP Selective Secondary Illumination material (RP SSI), which is a material that is applied to surfaces that you wish to receive secondary illumination.

RenderPipe MAX version 2.5 and earlier does not support 3dsmax 5 and VIZ 4's radiosity renderer.

 

Radiosity support and tips

Updated 28th January 2004

RenderPipe MAX (version 2.6 and later) supports the radiosity advanced lighting option in 3dsmax R5 / R6 and VIZ R4.

The radiosity solution is calculated by 3dsmax / VIZ on the workstation, then passed to RenderDrive and used in the render. Though the calculation of the radiosity solution is not accelerated by RenderDrive, the use of the solution is accelerated. In most cases switching on radiosity when using RenderPipe MAX has a smaller sweettoof.com time penalty than when using the scanline renderer.

For best results use simple geometry and ensure that geometry is not peeking into dark space because this will result in the triangles along that edge looking darker (for example, if a wall is partly under the floor).

A draw back with the radiosity solution is that where two triangles share vertices the stored radiosity value may be good for one triangle but bad for the other. For example, each vertex of a box is shared by at least three triangles, one for each side of the box. If the lighting is uneven the radiosity value stored for the vertex can only be perfect for one of the three sides.

Meshing parameters are not honored, so objects should be tessellated manually if the quality of radiosity solution needs increasing.

The Advanced Lighting (Lighting Override) material and LightScape material render as their base material, the lighting parameters being ignored.

Max's Exposure Control is not supported, use RenderPipe's Exposure Control instead located on the render panel.

A variable is available to adjust the radiosity bias. The variable is called 'radiosityBias' and should be added in the file RPMax.ini under the [RenderDrive] section. It should take a value from 0.0 to 1.0. The default value is 0.01, and values between 0.01 and 0.1 should yield the best results. If a scene shows persistent radiosity problems which cannot be fixed by either re-tesselation of the geometry or increasing the solution quality, try adjusting this value slightly. Note that you have to reload the scene after editing the variable.

 

 

What is the skylight shader and how do I use it?

Updated 9th December 2003

The skylight shader is a RenderMan light shader which gives daylight style illumination from a hemisphere. It is designed to be used to give the effect of outdoor illumination from the sky or for use with HDRI.

In version 2.7 the skylight shader has been improved and renamed RP_hdr_skylight.

To use the skylight shader, first create an RP RenderMan Light - choose the RP RenderMan Light in the Lights section of the Create view on the side bar, then click where you want the top of the hemisphere of light to be and drag down to where the centre of the hemisphere will be. (See chapter 17 for the RenderDrive manual or chapter 15 of the PURE manual for more general advice on RP RenderMan lights.)

Next swap to the Modify tab on the side bar. Under 'Shader:' click on the button labelled 'None" and choose the file skylight.sl.

Click on the 'Light Shader Parameters' rollout to open it. The following parameters are available:

intensity - this controls the intensity of the light, as for any other light.

lightcolor - this controls the color of the light.

texturename - this allows the illumination to be textured. The texture is multiplied by the lightcolor. The texture does not work properly in skylight.sl, which has been corrected in RP_hdr_skylight.sl. The texture coordinates used are spherical environment, and cannot be altered. This matches using the map in background set to have spherical environment coordinates, leaving all other settings unchanged.

spread - click on the button with a black triangle next to 'spread' and choose 'Angle'. The default value is 90 degrees. At this value light will come from the whole hemisphere, falling off in intensity towards the horizon. If you reduce spread to zero, the light will behave like a direct light, illuminating with parallel light rays. If you increase spread to 180 degrees illumination will be even from all directions, including from below.

from - this is the position of the light. Leave it set to Automatic so the light position is passed automatically and controlled through the viewports.

to - this is shown in the viewport as the light's target. As for 'from', leave it set to Automatic so the light's target position is passed automatically and controlled through the viewports.

RP_hdr_skylight_additions:

use_from_to - click on the black triangle next to 'use_from_to' and choose 'Check box'. If 'use_from_to' is switched on (or set to 1) then the shader will make use of 'from' and 'to'. If 'use_from_to' is switched off then the shader will ignore 'from' and 'to' and render as though the shader is pointing downwards in 3ds max's coordinate systems.

filterwidth - this sets a filter size to be applied to the texture. If you are using a texture it is worth setting a filterwidth of between 0.1 and 0.5, especially if using an HDR map or floating point tiff. Because the shader lights from all directions, bitmaps with a lot of variation can cause very long render times and noisiness. The filter smooths out the bitmap, reducing the render time and reducing noise.

This shader produces a very nice result and is well worth using on outdoor scenes.

It is not usually appropriate to use area light geometry with the skylight shader.

 

Speckles on some frames of an animation on scene with skylight shader

New 4th June 2003

The skylight shader can cause light colored speckles to appear over frames of an animation. This is sporadic and affects random frames. It will be fixed in a future software update. There are two ways to avoid it:

1. Relight without using the skylight shader

2. Re-render affected frames

 

Is QuickTime VR supported?

To render QuickTime VR we recommend you use our qtvr.sl camera transform shader. When you render using this shader you will get a single flattened image. You can then use the QuickTime package to create a QuickTime VR file. The same shader and procedure can be used to create files for equivalent formats too.

This is a very good way to produce high quality QuickTime VR. Most other methods reply on several flat renders, which are then stitched together, so introduces projection artefacts. The PURE / RenderDrive method produces a single image with no artefacts.

The shader can be obtained by e-mailing ART VPS customer support at [email protected].

To use the shader, apply it to your RP Camera using the 'None' button in the 'Custom projection shader' box.

To control the shader's parameters you need to edit the shader's header. The following parameters are available:

minaz and maxaz specify the azimuth limits (rotation about the vertical).

minel and maxel specify the elevation, the rotation up and down.

fov specifies the field of view. There is no point editing its value because RenderPipe sets it automatically from the RP camera's field of view. seat specifies the base point of projection relative to the camera and does not normally need to be changed.

aspect tells the shader the aspect ratio of the image. You MUST set this to be the image width divided by height. So if your image is 640 x 480, set aspect to 1.3333. To do this change the line near the top of the shader from:

uniform float aspect = 1)

to:

uniform float aspect = 1.3333)

 

Where can I find RenderMan shaders to use with RenderPipe MAX?

New 3rd March 2004

There are 11 shaders in the RenderPipe_MAX\example_shaders on the PURE / RenderDrive CD. Some of these shaders can be used directly, others are provided as example shells in which you can develop your own shaders. See chapter 17 of the RenderDrive manual or chapter 15 of the PURE user manual for more information about these shaders. The RP_HDR_Skylight shader is explained in the release notes and on page 10-18 of the RenderDrive user manual and 8-18 of the PURE user manual (November 2003 version or later). The QTVR and RPMetallicShiny shaders are explained in the release notes.

There are also a number of shaders on the example and tutorial CD in the 'RenderMan MAX Shader Examples' directory. The readme file in that directory explains what the shaders do.

To make the most of the RenderMan interface you can write your own shaders. The manual contains some advice about this, and lists some useful documents and books. If you need help with a shader let us know.

 

Is this third-party plug-in supported?

We are often asked if third-party plugins are supported. There are so many third-party plugins and they change so often that we can't give definitive answers for most of them. However, these general rules can be used:

Plug-ins that need to do shading at render time are not supported (though see Maps below). This means that third-party Materials, Lights and Environment effects are not supported.

Plug-ins specific to other renderers, such as anti-aliasing plug-ins for the default scanline renderer, are not supported.

Maps - 2D and 3D Map plug-ins are supported. The RenderPipe Texture mechanism is used to convert these types of Map to bitmaps. (See page 6-7 of the PURE user manual and page 8-7 of the RenderDrive user manual.) Other types of Map plug-in are not supported.

Almost all other plug-ins are supported. This includes Geometry, Modifiers, Particles, Dynamics and File Formats.

Render Effects and Video Post plug-ins are normally supported, though see page 6-12 of the PURE user manual and 8-12 of the RenderDrive user manual as these types of plug-in may depend on g-buffer channels, some of which are rendered differently by PURE / RenderDrive compared to the default scanline renderer.

Some plug-ins are a combination of types. In these cases, apply the above guidelines to each distinct part of the plug-in.

 

How do I make sure the Background appears?

Updated 9th December 2003

RenderPipe supports the Background (as set on the Environment panel) by inserting a surrounding sphere with suitable material at render time.

If the Background is not appearing when doing a RenderPipe render then check the following:

A camera view is being rendered

The camera is perspective, so is not set to be orthographic

Manual clipping is not switched on, or if it is on the ranges allow for a surrounding sphere

The bounds of the scene are not too large. For example if there is geometry with a coordinate of 600, 000, 000 then the background will not appear.

In RenderPipe MAX version 2.7 or later, RenderPipe also renders Backgrounds from Perspective viewports.

 

Direct lights or sun lights unexpectedly shadowed

When using RenderPipe MAX, direct lights shadow as though they are outside the bounds of the scene. If you surround your scene with a sphere to model the environment, the sphere will shadow the direct lights where ever the lights are placed. To eliminate the problem set the sphere not to cast shadows - right mouse click on it and choose Properties. Switch off the 'Cast Shadows' switch. In VIZ you will probably need to click on the 'By Layer' button in the 'Rendering Control' box, changing it to 'By Object' thus enabling the object controls.

See page 8-4 of the PURE user manual and page 10-4 of the RenderDrive user manual for more information about this.

RenderPipe MAX uses the RenderMan solar call to implement direct lights. It makes physical sense because direct lights are provided to model sunlight, which is a very distant light source.

 

Rendering stops without warning while sending geometry

(Updated 30 May 2003)

Firstly, if you are using the RPC plug-in (Real People, Trees etc) go through the advice in 'RPC (Real People, Trees, etc) support' above.

Secondly, search your 3dsmax installation for the cebas.dlu plug-in and if you find it remove it. Its presence causes the 3dsmax API to give an error when accessing some types of material. (This does not affect version 2.6 of RenderPipe MAX .)

Thirdly, if you are using version 2.4 of RenderPipe MAX, check that Background Environment map is valid. If the map is empty but switched on, the render will fail without warning. This does not affect version 2.5 or later of RenderPipe MAX.

Finally if none of the above advice eliminates the problem, you need to track down the object that is causing the problem:

First set the render mode to 'Selected', deselect everything using the 'Select None' option in the Edit menu, then render. If this render fails then the problem is with the lights, camera or environment. If it works then the problem is with geometry or materials.

If the previous test shows the geometry or materials are at fault, swap the render mode back to 'View'. Use the Display floater to hide objects and then render until you find the problem object. If you use a binary search this won't take long - hide half the objects and render. If the render still fails, then the problem is within the half of the objects still visible. If the render does not fail, then the problem is with the half of the objects that are hidden, so unhide them and hide the objects that were visible. Either way the scene is already halved. Repeat this process until you track down the problem object.

 

Using the index_of_refraction.ms and rplighter.ms MAX scripts

New 12th June 2003

Two useful MAX scripts are provided in the RenderPipe_MAX\scripts directory on the CD. They are:

  • index_of_refraction.ms - this script goes through all the max materials in the scene and sets their Index of Refraction to 1.0. This is useful because at the default value of 1.5 RenderPipe treats transparent materials as refractive.

  • rplighter.ms - this script converts all the standard max lights in the scene to RenderPipe lights, and switches off the original max lights.

 

To use the scripts:

  • It is a good idea to take a backup copy of your scene first, in case you are not happy with the result of the automatic conversion.

  • On the side bar, swap to the Utilities tab and select MAX Script.

  • Click on the 'Run script' button.

  • Browse to the script and open it.

  • In the drop down list of utilities a new option, 'IOR Fixer' or 'RP Lighter' as appropriate, will appear.

  • To enable the option you must choose the option in the drop down list and let go. You must do this even if the option you require is shown top most on the drop down list. When you choose the option and let go, a new rollout will appear containing a Go button and a Close button.

  • To perform the conversion simply click on the Go button.

 

Note that RP Lighter does not preserve all data, e.g. include / exclude lists, nor does it convert lights that are within groups. It does not convert photometric, lightscape or daylight lights.

 

Visible to Reflection / Refraction switch and index of refraction 1.0

New 12 June 2003

In 3ds max it is possible to set an object to be 'Visible to Reflection / Refraction', but not 'Visible to Camera' . The object will then appear in reflections and refractions, but will not appear when viewed directly.

RenderPipe supports these flags, but with one difference - the 'Visible to Reflection / Refraction' switch is treated as a secondary visibility switch so RenderPipe does not take account of index of refraction.

If you view an object that is visible in reflections and refractions, but not visible to camera, through a transparent object with index of refraction 1.0 then the object will be visible. Similarly if the object is visible to camera but not visible to reflection / refraction, it will not be seen through the transparent object.

 

Does RenderPipe MAX work with network rendering / backburner?

New 26th June 2003

Yes, RenderPipe MAX does work with the network renderer / backburner. See page 16-2 of the RenderDrive User Manual or page 14-2 of the PURE User manual for advice on setting it up - do look at the PDF version of the manual if using RenderPipe MAX version 2.6 or later.

Basically you set up network rendering as normal. If you had a RenderDrive and a PURE card you have two choices:

1. Run two network rendering servers on 2 different PCs. One server sends jobs to the PURE card, the other server sends jobs to the RenderDrive

2. Run one network rendering server. It will split frames so one part of the frame renders on PURE, the other part of the frame on the RenderDrive.

Note that the server will still run a copy of 3ds max / VIZ in the background - this will send the geometry to the RenderDrive / PURE, receive the rendered images back and apply any effects.

It is necessary to be careful about how you tell the server which rendering device to use. If you use the 'Save selection with scene' option, then setup number 1 above will not work - both servers will render to the same selection.

If you have more than one network rendering server, then you need to keep 'Save selection with scene' switched off. You must also be careful about changing the rendering device selection on each machine running a queue to avoid clashes.

 

Assertion error when rendering an RP Texture or an RPC in 3ds max 5.0

New 19th March 2004

This is specific to max 5.0 and RenderPipe MAX version 2.8-1. It does not affect 3ds max 4.*, 5.1, 6 or 6.1, nor Autodesk VIZ 4.

If you render an RP Texture or an RPC, then you will get an assertion error in rpsurfac.cxx. If you press OK the render may continue. If you press cancel 3ds max will crash.

To avoid this problem we recommend that you install the free update to 3ds max 5.1, which can be downloaded from Discreet's web site.

If it is not possible for you to upgrade to 3ds max 5.1 then please e-mail ART VPS support as we can provide an alternative solution.

 

Error message: "Assertion error D:\jej\...\rpsurfac.cxx: Line 3400"

New 8th September 2003

This is a very rare message. This assertion error can be seen when RenderPipe MAX is outputting the bitmaps used by a scene. It means that 3ds max has failed to properly load one of the bitmaps, but has also failed to give a proper warning.

A possible cause of the message is that there was insufficient memory available for the bitmap to be loaded, so large image files such as AVIs are most likely to be affected. Though there may appear to be sufficient memory it needs to be available as a single contiguous area.

If you see this message, try rebooting your machine, clearing up temp, increasing virtual memory, increasing your physical memory or finally simplifying the scene. Note this is very rare.

 

Region Net Render

New 10th February 2004

In 3ds max 6, Region Net Render is an option built into the Network Job Assignment panel - it is enabled by switching on the 'Split Scan Lines' option. In 3dsmax 5 and earlier, Region Net Render is a rendering MAX script.

Region Net Render allows an image to be split into parts, then renders each part using the network renderer / backburner, before finally stitching the resulting parts together.

Normally it is not appropriate to use Region Net Render with PURE and RenderDrive. If you have multiple RenderDrive and PURE cards, it is better to use frame splitting direct from the render panel. However, in the following cases Region Net Render can be useful:

  • You have an unreliable network

  • You want to benefit from the network renderer's queuing and scheduling

  • You are rendering an extremely high resolution image

Region Net Render has been tested with 3ds max 5 and 6 and RenderPipe. The script has not been tested with other versions of max and VIZ but should work as well.

For more information on Region Net Render see the max user documentation. For information about using RenderPipe MAX with the network renderer, see page 14-2 of the PURE manual or page 16-2 of the RenderDrive manual.

Note you should not use RenderPipe lens effects with Region Net Render, lens effects only work on complete images.

 

Matte / Shadow material rendering black

New 29th March 2004

To use the Matte / Shadow material in RenderPipe there must be a perspective Camera in the scene, otherwise the material renders black.

 

Matte / Shadow material - visible border

New 18th June 2004

It is sometimes possible to see the boundaries of a matte / shadow object, especially when using HDRI. There main reason for this is that the HDR skylight illuminates objects from a half dome surrounding them. This means that the shadow is much larger than you expect, though most of it is very subtle. For example, the light that comes from near the horizon on the left side of the object, casts an extremely long shadow to the right of the object. Just as at sunset shadows become extremely long.

A secondary reason is that RenderPipe calculates matte / shadow by sampling with shadows enabled, then sampling without. If the effect is inherently noisey then the boundary may be visible.

To overcome this, make the plane or object that has matte / shadow applied larger and try to ensure its boundaries match those of the object it is corresponding to in the scene.

 

HDRI and Shadows

New 29th March 2004

Shadows cast in scenes lit by HDRI lights are usually very subtle and soft. This is because the HDRI light illuminates from a 180 degree dome. Light rays come from the side as well as from above, lessening any shadow. This also makes the shadow larger than you expect because the object shadows rays arriving at an angle.

HDRI can be used with the Matte / Shadow material so that shadows can be cast "onto" objects in the HDRI background. Make sure the object you place in the scene with Matte / Shadow applied is large enough to catch the whole shadow as otherwise you will see the object's boundaries. HDRI shadows are much larger than you expect because light rays come from such a wide angle.