Hi there,
can i somehow make the Magma field object visible in render?
Thank you for reply in advance
You need to define a Color field and a Density field in your Magma. Just create a Color and a Density output node, and you can connect static values, or anything calculated in the Magma flow. Then you can add a Stoke Atmospheric Effect in the Environment dialog of 3ds Max.
thinkboxsoftware.com/stoke-m … ic-effect/
This will only render in renderers that support 3ds Max volumetrics - VRay, Default Scanline, finalRender. It won’t render in mental ray, iRay or Quicksilver. Also, if the density settings are too high, it can produce very ugly artifacts, so some tweaking the Density values of the Field or the Atmospheric effect might be needed.
The following screenshot shows a very simple Stoke Magma field which basically generates a Sphere with falling off density controlled by a Curve.(It takes the Position Magnitude, divides by the Radius, clamps between 0 and 1, Subtracts from 1 to invert (1 at the origin, 0 at radius distance), remaps the value with the Curve, outputs as Density and (yellow) Color.
I then created a Spot Light, enabled Shadows and Atmospheric Shadows, set the light to a shade of Red.
I created a Plane with a Raytrace material beneath the Field and set it to blue with some reflection.
I added a Stoke Atmospheric Effect to the Environment dialog, opened the UI and picked the Stoke Field Magma.
I also set the Background color to cyan:
STK_AtmosphericEffect_RenderSphericalField_v001.png
As you can see, the field renders in Scanline Renderer, casts a shadow on the plane, and is reflected in the plane.
I then reduced the Camera Density from the default Exponent -1 to Exponent -2 and re-rendered:
STK_AtmosphericEffect_RenderSphericalField_v002.png
Here is the same with the Reflection disabled:
STK_AtmosphericEffect_RenderSphericalField_v003.png
In the following version, I tweaked the Curve to produce a fancier distribution, switched the Reflection to Fresnel, changed the color of the plane material to white, and enabled custom Light Density in the Stoke Atmospheric to reduce the density in the lighting pass to 2.0E-2:
Alternatively, if you have FumeFX, you can export your Stoke Field Magma to FXD and render using Fume’s own Atmospheric effect which is much faster, supports Multiple Scattering etc.
I took the existing scene, exported the Stoke Field Magma to FXD, then dropped the MS file created in the output folder into the 3ds Max viewport to create the matching FumeFX Grid. I added the Spot light to the FumeFX light sources list, switched the Smoke Color source to “Grid” to use the correct color, and enabled the Cast and Receive Shadows options. Note that the result looks different because the Densities are unmodified (in the Stoke Atmospheric, we used different fractions of the field’s Density for lighting and for camera rendering):
Yet another alternative approach would be to create a VRay volumetric gizmo and use a Stoke Field Texmap to colorize it. This will be slower, but would allow for advanced GI effects.
There is also the Krakatoa path using the Stoke PRT Field object, but that requires Krakatoa, obviously.
oops, i’m sorry for confuse, i should be more specify. i meant to make visible in render all that velocity vectors as you see here 
The particles are a Particle Flow, right? So you need heavy motion blur, or you can replace each particle’s shape with a tall thin cylinder and set the particle to Rotation > Speed Space Follow so it turns with the Velocity to visualize the vector…
Ok, here is an example using a Cone as Shape Instance:
[attachment=0]STK_RenderMagmaFieldDrivenParticles_PFlow_Cones_v001.png[/attachment]
- I created a Cone primitive with Height of 1.0, Radius 1 of 0.1, Radius 2 of 0.01, 8 Sides, Height Segments 1.
- I added an XForm modifier and rotated about Y at 90 degrees because PFlow assumes the X axis is the axis aligned to the Velocity when using Rotate > Speed Space Follow.
- I then added a Rotate > Speed Space Follow operator to the PFlow, as well as a Data Operator that reads the Magnitude of the Speed, multiplies it by 160 (because it is in units per tick, but we want it per frame, and at 30 fps there are 160 ticks in a frame), and output as Scale X.
- I then added a Shape Instance and picked the Cone.
- I set the Display to show Geometry.
- Rendered the Front view in Default Scanline and got what you see…